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Fermentation Crocks: The Who, What, Where, When, Why and How

Do you want to easily and effortlessly make probiotic-rich fermented foods a part of your life?

Are you confused over what container to ferment in?

Are you afraid to eat food that’s been left on your counter to ferment for weeks and is now covered in mold? I am!

Are you tired of fermenting in make-shift containers?

Read on for the Who, What, Where, Why and How of fermenting in a water-sealed ceramic crock.

And when you’re ready to make some sauerkraut, here’s my How to Make Sauerkraut In a Crock in 7 Simple Steps [Healthy, Flavorful, Easy] recipe:

WHAT is a Fermentation Crock?

A fermentation crock is a stoneware pot designed to hold cabbage and vegetables as they ferment.

There are two primary types of ceramic crocks for fermentation available: Open Crocks and Water-Sealed Crocks. Both have advantages and disadvantages to consider.

Keep in mind that sauerkraut fermentation is best done in an anaerobic (without air) environment where the lactic-acid bacteria can best do their work and yeasts and molds – that can ruin your ferment and impart an off taste – are far less likely to grow.

Open Crock

Six white open crocks for fermentation in different sizes. |

Open crocks are readily available and are what most of us envision when the word “crock” is mentioned.

This popular crock is probably what your grandmother or great-grandmother made pickles in, especially in the U.S., home to crock producing capital, Zanesville, where the Ohio Stoneware company makes both open- and water-sealed crocks. You may even have one gathering dust somewhere in your home.

To ferment in an open crock, cabbage or vegetables are first packed into the crock and then a plate is placed in the crock – to hold whatever is fermenting below the brine. Lastly, a cloth is secured over the opening. With this set-up, outside air can still enter the crock.

We opened our first, water-sealed crock batch of sauerkraut today. Came out beautifully clear, so my wife and I are now believers in the method over our old school “pillow case over the open crock”. We sealed it on the first day and never looked again. This was a TSM Fiesta Harvest 15 liter.

What About Fermenting in a Food-Grade Plastic Bucket?

A plastic bucket is a type of open crock. Not only are you allowing mold and other potentially harmful bacteria – as discussed below – into your final product, but the lactic acid produced during fermentation can react with the material in the bucket and leach harmful chemicals into your ferment. Even with BPA-free plastic, other chemicals in the plastic could leach into your foods.

Advantages of an Open Crock

  • Generally, less expensive than a water-sealed crock and readily available.
  • Open top and straight walls make it easy to clean.
  • Easy to fit whole or large vegetables into.

Disadvantages of an Open Crock

  • Ferment prone to developing surface mold and/or Kahm yeast (a harmless yeast that appears when a ferment is exposed to air).
  • Older crocks may contain glazes unsafe for food use, especially crocks from Mexico.
  • Weights and lids often need to be purchased separately and can dramatically raise the cost of the crock.
  • If a cloth is used to cover your ferment, it’s prone to wicking brine onto the floor.
  • Easy for flies and fruit flies to get into and lay eggs in (not a welcome gift in your ferment).
  • Makes for a frustrating fermentation experience (Just read the Comment Section on my most popular post. Has Your Fermentation Gone Bad?).

Water-Sealed Crock

Five colorful handmade water-sealed fermentation crocks. |

A water-sealed crock is the ONLY style fermentation crock I will ferment in! Biases aside…

Water-sealed crocks are a bit more difficult to find, but as fermentation is sweeping the nation, they are starting to appear in stores and cottage industries are evolving and creating pieces of art worthy of living on your kitchen counter.

After a water-sealed crock is packed, two half-circle weights are placed into the crock to keep your ferment submerged. Then, the lid is placed into an open moat which is then filled with water. Now, outside air is prevented from entering the crock and carbon dioxide gases created during fermentation easily bubble out.

Advantages of a Water-Sealed Crock

  • Makes for a very easy, almost care-free fermentation experience (You have to keep the moat filled with water.).
  • Neither flies nor fruit flies can get into the crock and lay eggs.
  • Very little chance of mold or surface yeasts growing on your ferment.
  • Takes the guesswork out of making sauerkraut and other fermented vegetables.

Disadvantages of a Water-Sealed Crock

  • The water in the moat must be monitored and filled as necessary. If not, the seal will be broken and air will be allowed to flow into the crock.
  • Narrower opening makes it more difficult to pack your ferment.
  • Shape at the top of the crock, where the lid is, can make it difficult to clean.
  • Sealed environment makes it hard to monitor what is going on inside.
  • Generally, more expensive than an open crock.

WHY Use a Water-Sealed Fermentation Crock Instead of Jars?

Two images with the left image showing a brown Water-sealed crock and the right  showing mason jar with white lid filled with sauerkraut for fermenting. |

Now that you understand the differences between open crocks and water-sealed crocks for fermentation, I’ll share with you the advantages of fermenting in a water-sealed crock over a mason jar.

I am all for fermenting in mason jars, recommend their use for making sauerkraut and ferment about a third of our family’s annual supply of sauerkraut in jars.

My teaching recipe, How to Make Sauerkraut In a Jar in 7 Simple Steps [Healthy, Flavorful, Easy] uses mason jars for a fermentation vessel. It works great for consistently fermenting mold-free sauerkraut.

However, once you’re comfortable with fermenting in a jar and want to make larger batches or just want the greater depth of flavor that develops in the more stable environment of a stoneware crock, then I recommend graduating to fermenting in a water-sealed crock.

Fido jar and airlocks for fermenting. |

What About Fermenting in Jars with Clamp Lids or Using Air Locks?

Many people successfully ferment in either a jar with a clampdown lid or various jars with an airlock in the lid.

I have tried fermenting in the Fido-style jars with the clamp lids and for sauerkraut don’t find any great advantage in using these “fancy” jars over the inexpensive and readily available “Mason” or canning jar.

Using an airlock with the canning jar is a step up and there are some great choices on the market which I’m now using.

But, I want people to easily and inexpensively ferment sauerkraut. The mason jar is a great place to start.

The water-sealed fermentation crock is a great crock to graduate to once you have mastered fermenting in a jar and want to start fermenting larger quantities.

Advantages of Fermenting in a Water-Sealed Crock

Brown water-sealed fermentation crock broken down to show the inside parts and the outside like the weighing stones, deep water groove, and lid with convenient handle. |
  • The thicker stoneware wall creates a more stable fermentation temperature, resulting in sauerkraut with a greater depth of flavor.
  • Weights keep sauerkraut below the brine for safe and even fermentation.
  • The lid works with a water groove – which you keep filled with water – to form an airtight vacuum seal.
  • Gasses created during fermentation rise and escape via the water moat.
  • Brine can’t escape and overflow the vessel. Result? Sauerkraut with plenty of brine.
  • Odor is trapped in the crock. Music of bubbles escaping – plop, plop – but no smell.
  • Stable fermentation environment results in a greater range and number of beneficial bacteria.

Disadvantages of Fermenting in a Mason Jar

  • Brine can overflow resulting in a drier sauerkraut.
  • You have to loosen the lid – or don’t put it on super tight – to allow pressure to escape.
  • Not airtight. Air can enter the ferment.
  • Not always easy to find an effective “weight” to keep ferment below the brine. (A small “jelly jar” does the trick for me.)
  • Theoretically, a lower count of beneficial bacteria.
  • Inefficient if wanting to ferment a large quantity.
  • Odor in the home of fermenting sauerkraut.

WHO Should Use a Water-Sealed Fermentation Crock?

Anyone who wants to up the quality, depth of flavor and moisture content of their sauerkraut.

In addition, if you are struggling with severe health challenges, many recommend only eating sauerkraut that has been fermented in a truly anaerobic container – such as a water-sealed crock – where the beneficial bacteria have the optimal environment in which to grow.

Make sauerkraut with high counts of bacteria. |

For our sauerkrauts, we actually found our quality and consistency improved as we scaled up. It may be that a more vigorous fermentation is achieved with a bigger mass of vegetables and therefore bigger population of lactobacilli, or it may be due to a more successful airlock overall. – Dan Rosenberg, Real Pickles in Greenfield, Massachusetts

I want you to be successful fermenting in a crock. So, before you pull out your credit card, get comfortable first with fermenting in a jar.

Mistakes with small batches make for small losses. Success with a jar-sized ferment builds confidence and empowerment. So, first things first:

  1. Have you made a few jars of sauerkraut using How to Make Sauerkraut In a Jar in 7 Simple Steps [Healthy, Flavorful, Easy]? Wonderful!
  2. Do you feel comfortable making sauerkraut and do you know which flavors your household prefers?
  3. Do you have a rough idea how much sauerkraut your family eats?

Yes, Yes and Yes! Then, let’s figure out what size crock you’ll want to purchase.

WHAT Fermentation Crock to Purchase for Your Needs?

Crocks are sized in both liters and gallons, depending on the manufacturer. I own a 5-liter, a 10-liter and a 3-gallon crock. I love them all. I use them all.

Usually, the size of the crock denotes its capacity. That is, how many quarts or liters of sauerkraut you can ferment in it. The crock is actually larger, than the size noted, to allow space for the weights, brine and expansion of the contents as it ferments. (NOTE: Harsch crock sizing is based on actual size. Keep that in mind if you own one and are trying to figure out how much cabbage you can pack in it.)

I recommend the 5-liter crock for most households. You’ll pack a 5-liter crock with about 10 pounds of cabbage and harvest anywhere from 5 to 6 quarts of sauerkraut from it. It is not too heavy to lift when full and it fits into your sink for washing.

A 10-liter crock also works great, especially for larger families. I pack it with 20 pounds of cabbage and harvest 10-12 quarts of sauerkraut from it. However, it is a struggle to lift and a little more difficult to fit in my sink for washing. But, the 12-quarts of sauerkraut it produces makes the drawbacks manageable.

Korean kimchi inside metal bowl. |

If you consume what the average Korean does – 1 quart of Kimchi weekly! – you might want to consider something larger than 10 liters.

My 3-gallon (11.4-liters) crock gets filled once a year with enough cabbage and vegetables – 25 pounds worth! – to make 12-13 quarts of Sweet Garlic Sauerkraut, the family favorite.  Its size makes it too heavy to move when full. So, I pack it in the same location that it will be fermenting. It is awkward to clean in most sinks

Since it’s nice to have a smaller crock to make a few flavor-packed jars of any of the many sauerkraut recipes I’ve developed, my next purchase will be this 1-gallon crock in my favorite colors.

I consider fermentation crocks to be heirloom items that I will be able to pass down through my family. May sauerkraut nourish and live on in my family – and yours – for many generations to come.

Some things to keep in mind as you consider the various styles and sizes of crocks.

  • Is the crock the right size for your needs? Crocks are sized all the way from 2 quarts to 40 liters. How much do you eat in a week and how often do you want to ferment?
  • What do you plan to ferment in your crock? Pickles, whole onions, corn-on-the-cob and other vegetables can all be fermented in your crock and may sway you on what size crock to purchase. See Ferment Your Vegetables: A Fun and Flavorful Guide to Making Your Own Pickles, Kimchi, Kraut, and More, by Amanda Feifer for some non-sauerkraut crock recipes.
  • Once full, are you able to pick it up and move it around? A 5-liter crock will weigh approximately 25 pounds when full. I can easily carry it around.
    My 10-liter crock weighs 35 pounds when full. Thar’s a struggle to move.
    My 3 gallon, 50 pounds! I don’t move that and instead, pack it in place.
  • Can you fit it in your sink for washing?
  • Are the handles functional? For most crocks, they aren’t! Only my Harsch crock has a useful depression on the underside of the handles. Most are flat and I never feel I can get a good safe grip. So, I wait to put the lid on and carry the crock by putting my hands into the opening. A workable fix.
  • Do you know the reputation of the company making the crock? You want to make sure food-safe clay and glazes are being used. For me, Germany is the classic location, but I’m learning that the crocks from Poland are of a similar quality. China is another culture deeply steeped in fermentation as one of my readers recently pointed out:
    “The Chinese have been using water-sealed crocks for thousands of years especially in the countryside where they are ideal as a perfect seal against insects etc. I live in Sichuan in a third tier city and I know that at least 8 out of ten families keep one or two of those crocks under the sink. They replenish the crocks with whatever vegetables are in season, from peppers to carrots etc. and rotate the crocks.”
  • Where do you plan to store it? If you want to keep it on your counter and use it throughout the year, do you need it to fit under your upper cabinets? Or, will you make sauerkraut seasonally and store your crock in the garage or basement?

WHERE to Buy Water-Sealed Fermentation Crocks?

When I bought my first fermentation crock back in 2002, my only choice was the German-made Harsch crock. I bought the 10-liter size and still use it to this day. Though it is no longer available, have no fear; you now have many choices!!!.

With the power of the internet and the growth in fermentation, there are many wonderful crocks to choose from. Below are currently available brands. Most can be found on Amazon – though not always at the best price – where you can drive yourself crazy reading all the reviews. All come with a 2-piece stone weight unless noted otherwise.

Shipping costs can greatly impact the cost of the crock you decide to purchase. Visit the website to determine current shipping costs. There are a few with free shipping.

Actual dimensions and weights are pulled off the internet and may not be 100% accurate. Different websites had different numbers for the same crock.

I tried to find the best prices at reputable companies and include links, with Amazon being the only affiliate links at this time. Pick the best one for your needs and enjoy making many batches of mold-free, flavor-rich sauerkraut for years to come. Most links are for the 5-liter crock. Use that link to also access other sizes.

If you live outside the US, scroll down to the Canada, Australia & New Zealand and Europe sections for a listing of companies servicing those areas.

Boleslawiec Polish Fermenting Crock

Brown boleslawiec fermentation crock with the pale yellow stone weights placed outside. |

Handcrafted with the rich, abundant clay by the by local artisans in the Boleslawiec Region of Poland, the Boleslawiec Crock is crafted by those with 60 years of experience.

The quality of these Polish fermenting crocks is on par with the popular Harsch Gairtopf fermentation crocks from Germany but at a much more affordable price.

Sizes: 5-20 liters (1.3-5.3 gallons)
Glaze: Lead and Cadmium-free
Made In: Poland

Specification for a 5-liter (1.3 gallons) crock:
Height: 12.25 inches
Diameter: 10.25 inches
Weight: 14.95 pounds

Luna glass crock weights. |

NOTE: All the Boleslawiec crocks sold by Stone Creek Trading come with lead-free glass weights as an alternative to the traditional porous ceramic weights which are sold with most fermenting crocks. From their website:

“With traditional ceramic porous weights, the unglazed surface can absorb bacteria present in your ferment. When something goes wrong in the fermentation process, the bad bacteria or mold can be absorbed into the porous stones. It can be very difficult to then sanitize the porous stones. As an alternative, glass is non-porous and will not absorb anything!”

In addition to being non-porous:

“Luna Glass Crock Weights are 15% heavier than the traditional porous weights. The additional weight helps keep your ferment submerged where you want it.”

I’m excited to try a set of these. From one review: “Glass weights are great as they don’t absorb odors or stains and allow you to see food beneath.”

5-liter Crock at Stone Creek Trading Impeccable customer service. Comes with lead-free glass weights and recipes for pickles and sauerkraut. Shipping only to the US.

Schmitt Fermentation Crock

Brown Schmitt water-sealed fermentation crock with brown stone weights placed outside. |

German manufactured fermentation pot. This traditional pot is suitable for almost all types of vegetables including cabbage, pumpkin, cucumber, carrots, and more. Stoneware does not require special storage or care and is neutral for all fermented vegetables.

The crock comes in a dark brown color and it is supplied complete with lid, stone weights, and instruction booklet.

Sizes: 5-10 liters (1.3-2.6 gallons) capacity
Glaze: Lead and Cadmium free
Made In: Germany

Specification for a 5-liter (1.3 gallons) crock:
Height: 10 1/2 inches
Diameter: 9 inches
Weight: 16 pounds with weights

5-Liter Crock at Lehman’s  They also have a 3-gallon USA made crock.

Harvest Fiesta Fermentation Crock

Brown Harvest Fiesta water-sealed fermentation pot with the lid placed leaning against the crock and the pale stone weights placed on top of each other. |

Harvest Fiesta Pots are skillfully designed and made by local artisans in the Czech Republic. They are fired at temperatures over 2000 F and their heavy earthenware composition features a distinctive rich brown character with a lead and cadmium free glaze. Intended for long-term food storage, their artisanal design features an extra-wide opening, making it easy to load all of your favorite vegetables for maximum yield. Stone weights are included.

Notes from Reviews:

  • Emblem is a sticker that easily falls off.
  • Handles are easy to grab.

Sizes: 5-20 liters  (1.3-5.3 gallons)
Glaze: Lead & Cadmium free
Made In: Czech Republic

Specification for a 5-liter (1.3 gallon) crock:
Height: 10 inches
Diameter: 11 inches
Weight: 11.94 pounds

TSM Products Harvest Fiesta Fermentation Pot with Stone Weight, 5-Liter
56 Reviews
TSM Products Harvest Fiesta Fermentation Pot with Stone Weight, 5-Liter
  • 5 Liter fermentation pot with water channel or gutter Oxygen and mold free environment for...
  • Lead and cadmium free ceramic and comes with stone weights
  • Hand wash rinse and dry with cloth or paper towel


Ohio Stoneware

White Ohio Stoneware water-sealed crock. with 2 blue stripes wrapping around the body of the crock and a white lid leaning on the side with a blue stripe around the rim. |

I own this 3-gallon crock made by Ohio Stoneware. It is large, but I love it for those extra-big batches of sauerkraut. I think I packed 30 pounds of my Kimchi sauerkraut recipe into this crock last fall. It’s too heavy to lift when full, so I packed it right where it would be fermenting.

Sizes: 3 gallon (11.4 liters)
Glaze: No lead or harmful chemicals
Made In: USA, Ohio

Specification for a 3-gallon (11.4 liters) crock:
Height: 15 1/2 inches
Diameter: 11 inches
Weight: 21 pounds

  • Clean, smooth lines.
  • Weights are large and heavy to better hold the ferment below the brine.
  • Very reasonable price for this size of crock.
  • Walls are thinner than with most other ceramic crocks.

3-Gallon Crock from Red Hill General Store

Pressure Cooker Outlet

Art that Makes Food: Fermentation Crocks Individually Handmade by Artisans

Mark Campbell Ceramics

Mark Campbell water sealed fermentation crock in dominant yellow with blue patterns and drip paint effect at the middle of the crock. |

These crocks are wheel-thrown and made-to-order with your choice of glaze colors.

Design one to sit on your kitchen counter to daily add beauty to your home and inspire you to make sauerkraut! More about Mark Campbell Ceramics here. Be sure to check out his beautiful bowls.

LISTEN HERE to Mark discussing his business and journey into the fermentation world on The Fermentation Podcast, 40:23 minutes. Show notes include a video of him making a 1-gallon crock and his Taco Kraut recipe.

He totally gets how flavor-packed sauerkraut can dramatically and effortlessly shift the flavor of a meal which is why I’m always creating new recipes.

Sizes: 2 quarts (2 liters) and 1 gallon (3.8 liters) are the standard sizes, but will custom make other sizes
Glaze: Non-toxic, food-safe
Made In: USA, California (Shipped worldwide)

Specification for a 2-quart crock:
Height: 8 1/2 inches
Diameter: 7 inches

  • Extra large water reservoir (spend less time keeping it filled).
  • Water moat includes a pour spout (makes it easier to remove water from the moat).
  • Weights completely glazed (easier to keep clean and mold free).
  • 224 reviews!

Sarah Kersten

Sarah Kersten water-sealed fermentation crock in white in small and medium sizes. |

Modeled after a traditional Chinese design, these crocks are designed by Sarah Kersten and hand crafted at her studio in Berkeley, California.

Sarah’s work is inspired by her love of beautiful, functional ceramics, and her desire to produce heirloom-quality fermentation crocks.

Crocks come with glazed porcelain weights and a letter-pressed booklet of recipes and instructions.

Sizes: 2 quart (2 liters) and 6 quarts (5.7 liters) capacity
Glaze: Non-toxic
Made In: USA, California

Specification for a 6-quart (5.7 liters) crock:
Height: 10.5 inches

Live in Canada?

There are now two companies in Canada that carries water-sealed fermentation crocks.

Bio Supply

Black Schmitt & Sohn water-sealed fermentation crock and brown stone weights one leaning against the crock and the second leaning against the other. |

Bio Supply carries the Schmitt & Sohn fermentation crock in a variety of sizes. With typical German ingenuity, these crocks are created with a modern twist using a natural clay slurry which reduces the weight while increasing the durability.

Bio Supply will ship across Canada. Contact them for shipping costs. Their store, House of Nutrition, is located just outside of Victoria, so if you live on Vancouver Island you can pick one up at their store and save on shipping.

Mustard Seed Clay Creations

One brown fermentation crock made by Mustard Seed Clay creations with engraved square design in the middle bordering an intricate swirling sun pattern. |

Ray and Bev Niebergall live on the beautiful Sunshine Coast, near Vancouver, B.C. and run a full-time pottery studio, Mustard Seed Clay Creations, making functional and artistic one-of-a-kind pieces that would look beautiful on any counter.

The crocks are available in 3.7 liters (1 gallon). Larger or smaller ones can be made on request.

The glaze is food-safe and lead-free. They are available in 2 glazes: one is a Japanese Shino glaze which has wood ashes from our stove sprinkled on prior to the glaze firing; the other is a Kaki glaze, very smooth and durable. They chose glazes with an earthy, depthful look to complement the product inside.

They are in the process of developing a website. Until then, they can be contacted at rbniebergall AT gmail DOT com

Live in Australia or New Zealand?

Scythes Australia

Brown Zaklady water-sealed fermentation crock with white lining the rim. |

Scythes Australia is located in Mudgee, NSW. They import fermentation crocks from Zaklady Ceramiczne that are made at a factory in Poland.

Scythes Australia carry the 5, 10 and 20-liter water-sealed crocks complete with weights and a set of fermentation recipes. I think these crocks are made by the same company making the Boleslaweic crocks shown at the beginning of this section.

Mad Millie

Green Mad Millie water-sealed fermentation crock with the brand name in black background and white lettering in the middle. |

Just the color makes me want to buy one of these.

The Mad Millie crock is a 3-liter comes that is shipped with 2 traditional clay weights, instructions and recipes.

European Based Companies

Ken Bours Ceramics Agency

Brown Ken Bours sauerkraut pot with intricate painting of landscapes over the body of the crock and the two white stone weights displayed at the side. |

Ken Bours Ceramics Agency is located in Nederland and ships worldwide.

They carry a variety of water-sealed fermentation crocks in sizes from 2-liters to 25-liters. Style vary all the way from the traditional straight-walled to hand-etched rounded. Some are handmade by master Dutch Ceramist Daniel Lebon.

WHEN to Ferment in a Crock

Illustration of a tree with leaves changing into the four seasons of summer, spring, fall and winter. |

Image by Shelly


Just about any time that works for you with all that you are juggling in your life.

When I bought my first crock – a 10-liter Harsch Crock – I made a batch once a month. Just when my family was about to finish our last jar of Dilly-Delight Sauerkraut (The only flavor I made at that time.), the next batch was ready to harvest.

So, on my next shopping trip into town, I would purchase 4 or 5 heads of cabbage and get to slicing. With this approach, I was fermenting throughout the year and able to notice changes in the sauerkraut depending upon the temperature I was fermenting at.


Fall, when cabbages are plentiful at the markets – at least in North America – and there have been a few frosty nights to sweeten the cabbage is a great time to make sauerkraut.

Now that I have not only great local sources for cabbage in the fall but an extra refrigerator to store a year’s supply of sauerkraut, I make the bulk of my sauerkraut seasonally. Nothing beats a fully-stocked refrigerator.


Hot summer when higher temperatures fall outside the ideal range.

If temperatures are on the warm side, ferment for a shorter time period, 2 to 3 weeks instead of 4 to 6 weeks.

HOW to Ferment in a Crock

Partial view of a brown fermentation crock, two round green cabbages and two onions on top of a red and white striped cloth in the background, green peppers in the foreground, two small glass bowl with spices and the two brown stone weights on top of each other. |

I have published the How to Make Sauerkraut In a Crock in 7 Simple Steps [Healthy, Flavorful, Easy] recipe where I go into greater detail and include many pictures on how to make sauerkraut in a crock.

5 Pounds Cabbage & Vegetables – 3 Tablespoons Salt

This quick overview is here just for a summary. See How to Make Sauerkraut In a Crock in 7 Simple Steps [Healthy, Flavorful, Easy] for the full recipe, but for now here are a few points to keep in mind:

  • Make sure you have successfully made a few jars of How to Make Sauerkraut In a Jar in 7 Simple Steps [Healthy, Flavorful, Easy]. This recipe teaches the basics for you to be successful when fermenting a large batch.
  • Make successive 5-pound triple batches. A triple batch would call for 3 times the ingredients listed in my recipes. This quantity just fits into an extra-large mixing bowl.
  • Use 3 tablespoons of salt for each 5-pound batch.
  • Pack tightly into your crock, repeating with successive 5-pound batches. Stop 4 to 6 inches from the crock opening. Pack any excess in quart (liter) jars.
  • Place weights in, pressing down firmly to get the brine to rise above the weights.
  • Put the lid on, fill the trough with water and enjoy the music that will ensue in a couple of days. Monitor the trough, making sure it is kept full of water. This is your anaerobic seal.
  • Find a home for your crock, where it can ferment undisturbed for 4-8 weeks at 65-72 degrees Fahrenheit. To protect your floor from condensation, raise the crock off the floor with a few blocks of wood. The bottom of most crocks is not glazed and moisture does transpire through to the floor.
    Ferment for a longer time if temperatures are cooler; shorter time if temperatures are warmer.
  • When fermented to your liking, pack in quart (liter) jars and store in your refrigerator.
  • When done with the fermenting, store the weights in an open-air environment, or let thoroughly dry. I used to store my weights in the crock where traces of moisture still in the stone resulted in moldy stones. No fun.

HOW to Care for Your Crock

Luckily, these crocks are pretty much carefree. There are a few things to be aware of, however.

Smoothing Out the Edges

Inspect your crock when it arrives. If you notice some rough edges, here’s a tip left by a potter in one of the comments sections:

The unglazed edges on the various crocks and lids are often rough enough to scratch a counter. Before using your crock, simply get wet-dry sandpaper (the black stuff) and do 20 seconds with 180, 200 and 220 grit and then 20 seconds with 400 grit under running water and those edges with be super smooth.

Avoid Ruining Your Floors

Brown crock on top of wooden blocks to protect your floor. |

The bottoms of most crocks are not glazed and moisture can transpire through to the floor. When fermenting with your crock, make sure you protect your floor from condensation. Raise the crock off the floor with a few blocks of wood.

Removing Mold from Your Weights

According to Mark Campbell of Mark Campbell Ceramics, as discussed in this podcast, mold can’t be removed with bleach. He believes all the bleach does is dye the color of the mold; it does not completely remove the mold.

Instead, he recommends cleaning the crock and weights with some vinegar and then washing them well with soapy water. Next, put the weights (not the crock) inside a cold oven and then turn the oven on to 250 degrees and let them sit in there for 30 minutes. Turn the oven off and wait for the weights to cool down so that you can remove them with your bare hands.

The heat and the vinegar will kill the mold. Mold is more of an issue with unglazed weights. With glazed weights, it is much easier to just rinse off the mold.

Storing Your Crock and Weights

Early on, I stored my unglazed weights in my crock. Bad idea! The next time I opened my crock, I was greeted by mold-encrusted weights.

Weights need to dry in open air for a good week to make sure there is no longer any moisture left in them. I do this and then store them by themselves in one of my kitchen cabinets.

Which Fermentation Crock are You Lusting After? Know of a Company I Need to Add to the List?

Please share in the Comments Section. Thank YOU!

Last update on 2021-10-24 / Affiliate links / Images from Amazon Product Advertising API

75 thoughts on “Fermentation Crocks: The Who, What, Where, When, Why and How”

  1. Mine is from Ren Bours. I’ve ordered a 5 litre, in mustard (ready in January) I live in U.K. I really want the glass weights, I’m reliably informed that Stone Creek Trading will be operating in Europe by February 2016, so I’ll get some then. Very informative article, thanks.

    • Hello Johnny, Glad you enjoyed the article.

      Stone Creek Trading is sending some weights my way to review. I’m anxious to try them in one of my crocks that have rather meager weights.

      Were you satisfied with your experience purchasing from Ken Bours? How did you select a crock with so many to choose from?

      • Hi Holly (Ren Bours not Ken) My girlfriend chose the crock and also the 5L mustard one, coming soon. I’m not convinced that porous weights are what I want, so I’m looking forward to Stone Creek Trading expanding their operation, to include Europe. The fact that these weights are heavier, is a bonus. Very straightforward purchase, lovely crock.

  2. Hi Holly,

    Have you ever heard of the water in the lip getting sucked into the Crock? The other day I noticed the water level was low, below the cut out on the lid. I topped it back up. Today the water is overflowing…So I removed some with a turkey baster. The ferment is just starting its 3rd week.

    Is it possible that the water sucked into the crock will ruin the ferment?

    I am going to ride it out 2 more weeks and then jar…fingers crossed.


    • Hello Steve, Yes, I’ve dealt with this issue and I’ve heard from others experiencing the same.

      But I don’t think it gets pulled out of the moat. I think it just gets pulled to the inside half of the moat. Another gal working on a batch had this same experience and used your turkey-baster trick. 🙂

      If the water did go all the way into the crock, it’s not enough to upset the salt balance.

      Next time you notice a “dry” moat, jostle the lid ever so slightly and the water should move back. This happens more with large temperature swings – I think – or barometric changes. Hope all is good.

      • Thanks, there was a big swing in pressure…we recently had a storm blow through. So I guess the Crock also doubles as a barometer!

  3. Hi! Great info, thanks! I own a German made (I think) crock that is fairly sizable but I really love. It holds water around the lid and does a wonderful job of keeping out mold and scum on the inside. Based on your assessment of just fitting into the sink, I guess it’s a 10 liter. Anyway, I’ve made only sauerkraut in it for the past 5 or 6 years and filled it up with cabbage each time, but I want to branch out to other vegetables, smaller in batch. Can you ferment only half a crock of something, or would that create too great a chance for mold? I wouldn’t mind having a 2nd smaller crock but not sure if I really need to spend the $$ or just use what I have. Your thoughts?

    • Hello Karla, Ideally, you would fill it, but with a 10-liter crock that’s an awfully big batch of vegetables. I understand your dilemma. I would first try a few vegetable brine ferments in quart jars to get a feel for it and see what you like.

      I would highly recommend the book Fermented Vegetables by Shockey, if you don’t want to search the internet, for some flavorful ideas.

      Then, try a batch in your crock maybe only filling it halfway and see how it goes. I can’t say. I’ve only done sauerkraut and kept to fairly full batches. But, with the water-sealed environment at least you’re stacking the deck in your favor. See how that goes before buying another crock. However, I own 3 and am happy to have sizes to choose from and will be buying a gallon-sized next for small batches and to also do fermented carrot sticks.

      To get a better idea on its size, you can fill it with quart jars of water. Best of luck.

  4. I have the same 3 gallon Ohio Stoneware crock that you have. It does not have weights and I am not sure which weights to buy.

  5. Is there anything you can use to seal a crock with a crack? My father in law has a 30 the has a hairline crack and he’d like to repair it if possible. Thanks for any tips!

  6. Hi, nice overview!

    As I am looking for a crock (German living in Canada and need Kraut…) and since I am soon for a few days is Germany, I plan to buy a pot there, much cheaper then in North America.

    I checked both the Polish and Czech, but with a German shipping address the German companies are the cheapest. But I just wondered, there are 2 different “Schmitt” who do pots, about the same price, and look very similar. Actually, the only difference I can see is the label.

    I guess both are completely fine, just wondering which is the one you mention:

    Actually, the addresses of these are just 5 km from each other, so they must be somehow related, but still have different owners, according to the webpage… Funny thing.

    • Good idea. I likewise do most of my shopping when in the states, with US$. I would just make sure they are made in Germany and not China where some are starting to be made. The weights for the “Schmitt” labeled one is what I have and the weights are a little on the light side. If you can get the actual weight of the weights, I would go with the heavier one.

      Also, did you check the Ren Bours company shown above? They seem to be a higher quality to me. Bit higher on prices, I think.

      • Thanks for the tip! I just asked both of these German Schmitt companies, there are indeed the same family (parents and son, 2 different companies, same pot). Interestingly, you have a photo with a label from my first link, while bio-supply has the version with the other company’s label… Nevertheless, this pot is not made in Germany but in the European Union, according to both shop owners. So I would guess Czech or Polish, which is fine too.

        This gray pot is made in Germany and differs from the one in your article, and is more expensive (for 4l instead of 5l -> 40€ instead of 20€): . Not sure if it’s worth the difference.

        Got unfortunately only the weight of the pots, not the stone’s weight…

        And yes, I checked out Ren Bours as well, still waiting for an answer from him, as he has different pots. Only slightly more expensive then the German ones, so not a big deal.

        In the end: crazy that these pots cost about 3 times the price in North America, in Germany it is easy to find one for 30 €, including VAT and shipping, while here in Canada it is more 100 CAD, plus VAT and shipping… (for a 5 l pot). I guess it is mostly the shipping weight which makes it so much more expensive…

        Cheers from Montréal!

        • I bought my pot a few years ago through and was told it was made in Germany. Interesting to see they are now made in the EU. I wonder if the quality has changed.

          I would want handles that are usable, weights that are heavier than lighter and a decent-sized water trough. But… don’t drive yourself crazy trying to decide. It’s just great you can get one outside of Canada for yes, prices here are crazy.

          • Happily transported the pot in the hand luggage around the world, and now had my first batch ready after 4 weeks. Kraut, some carrots and some crazy huge dill plant stems, all left when we cleaned the garden, were packed in together. And since we Germans (and Scandinavians and east Europeans) love caraway, some went in the pot as well. Pot was finally only half full, but nothing gone bad, so all good. Everyone who tried it loves it! (my girlfriend was surprised that Sauerkraut fits so great to tempeh, I did this , with my homemade German style rye bread. Just have to try to do tempeh by myself, it’s fermentation in the end 🙂 )

            But the next round will probably some kimchi, since I found some cheap daikon…

            Anyways: Happy with the pot! (and you’re right, it handles could be a bit bigger, but I can live with that…)

          • The things we do to make good food! Your determination paid off. Thank you for the update and the recipe – looks scrumptious. I’ll link to that on my “Ways to Eat” page.

  7. Instead of filling the moat with water, I fill it with olive oil. It has the exact same air-tight seal as water and allowing the gas out through bubbles, but even better, it does not evaporate so you can truly just forget about the ferment for 3 weeks.

    • What a great idea! Thank you for sharing. Let me know how it works for you.

      Might be messy to clean up, however. And, I do know some have the moat water getting pulled into the crock (barometric pressure changes) so that could be an issue. Food for thought.

  8. Interesting that you state you don’t trust/like Chinese watercrocks. Any reason(s) for this ?
    For your information Chinese have been using these for thousands of years especially in the country side where they were ideal for a perfect seal against insects etc. I live in Sechuan in a third tier city and I know that at least 8 out of ten families keep one or two of those crocks under the sink. They replenish the crocks with whatever vegetables are in season,from peppers to carrots etc. and rotate the
    Crocks of varying sizes and materials are readily available from any market or grocery store here and they only cost a few dollars. My glass (yes glass) 5 gallon crock cost me less than $5.00 Aus.

    • Hello Marius, Thanks for calling me out on this. My concern is with what materials are used in the glazes. So, I guess it would be best to say “Purchase from a reputable company that can ensure they are using food-safe materials.” Made that edit. 🙂

      Thank you for sharing how the Chinese have been using them and it’s nice to know they are still a part of the culture. Are they mainly nuka-style pickles? Or, brine pickles? Would love to see a picture of one of your crocks and what you have in it.

  9. This is a wonderful crock overview, thank you!

    For what it’s worth, I have yet to be convinced surface molds are a problem that requires a special crock. As Sandor Katz recommends, if surface molds develop just scrape the affected veg and discard. Thus far, I’ve been I’ve been using the open crock method with food grade buckets I obtained for free from the grocery store bakery department, and have yet to develop surface mold. I look forward to obtaining a ceramic crock in the future, but for now food grade buckets are working just great.

    • Hello Mark, Thank YOU and I’m so glad you have a fermentation method that works and that you’re fermenting. That’s what counts and not obsessing over details that prevent forward momentum. 🙂 a small “fault” of mine…

      • No harm no foul! Obsessing over the details is good too. : ) Exciting news for me is that I did borrow a harsch crock from a friend, so right now I’m giving it a test drive. I still have surface scum generating on the top after a week or so, however. Does this happen in your experience? Is there a sealing method you enjoy? While the surface molds and scum doesn’t bother me too much, I would certainly like to get to a point where they can be avoided or minimized.

  10. 4 available as of 03-10-2017 on eBay.


  11. The Mad Millie fermenting crock is nice, I like the color, but over $200.00 for a 3 quart crock is way to expensive, especially when you can get a custom made, custom color crock from Mark Campbell for way less, his work is great,and his colors are amazing, so glad I found him on your web site, I have a five quart crock ordered from Mark in his sunset color, hope to send you a photo soon. I already have an oil bottle to match the crock, next up is a 10 quart kombucha crock!

    • A good question. I measured the three I own (4 3/4 to 6 inches) with the Ohio Stoneware 3 gallon one being the 6 inches. I can’t see more than 2 heads of cabbage fitting in in, however. Hope that helps.

    • You’ll want to make sure it is restaurant-grade (316, 18/8), or marine-grade (304) stainless steel which is designed to not break down in acidic and saline solutions. You’ll also want to make sure gases can escape by leaving the lid loose, especially during the first week. A creative solution if all works.

  12. I found some Chinese water sealed crocks for ten dollars. They look like the Chinese crocks selling for 39 dollars on amazon. Are these safe?

    The crocks have a white glaze inside and out and complex blue pattern on the outside. The lid looks like a rice bowl and there is a flat inner lid too. Store was going out of business, it was an impulse buy.:)

  13. I found some 2L Chinese water sealed crocks for ten dollars. They look like the Chinese crocks selling for 39 dollars on amazon. Are these safe?

    The crocks have a white glaze inside and out and complex blue pattern on the outside. The lid looks like a rice bowl and there is a flat inner lid too. I bought the last one. Store was going out of business, it was an impulse buy.:)

  14. Hi!

    I’ve been fermenting for about a year now and use a gallon glass jar and rig up a lid for it.

    The other day I was at the store and saw the Ohio Stoneware 3 gallon crock and (per your recommendation) purchased it.

    Once I got it home I realized how huge it is and am wondering; if I only fill it half way will the fermentation gasses be enough to displace the rest of the air in the container? Or should I keep looking for a smaller crock?


    • Yes, that is a BIG crock and ideally, it should be 3/4’s full or you end up with too much air and the greater chance for mold and yeasts to inhabit – not what we want. I would recommend a smaller crock. The 5-liter makes 4-5 quarts of sauerkraut. Read back over the section on what size crock is best for your needs and go from there.

      • Thank you for your help!

        After re-reading the crock size section I ordered the Stone Creek Trading fermenting crock 5L you reviewed on another portion of your site. It looks like it’ll give me a little more room than my 1 gallon glass jar and I can always get another one in the future for more capacity or experimentation.

        Your website is such an incredible wealth of information!

        Thank you for your time!


  15. Hello, I purchased the Polish Boleslawiec pot. I put gherkins, garlic and pickling spice in. I made the brine according to the directions provided. I peeked 2x (day two and day three) before I read the part that said don’t open the lid. Is my batch ruined? Thank you!

  16. Hello Holly,

    Hope all is well with you.

    Thanks for the excellent website and all the information.

    Following your lead and instructions we’ve just made a batch of red cabbage/beetroot/apple sauerkraut in a 5l fermentation crock for the first time. Left it completely alone on the kitchen counter next to a thermometer which recorded the daily max and min temps. It’s sat for 3 weeks at a pretty steady 20-23C and has come out perfectly. Many thanks. Very pleased and I can wholeheartedly recommend the crock method.

    We’ve just decanted it into jars and put it in the fridge. I noticed a few small air bubbles in the jars as I packed them and topped them off with the fermentation liquid. I did my best to get rid of the bubbles but in case any are left are they likely to cause any problems? Obviously I understand there could be the risk of mould, but I imagine they’ll be in the fridge for weeks rather than months and there is quite a lot of liquid.

    Many thanks.


    • Hello Raj, You’re quite welcome and I’m happy to hear of your success. I need to look into one of those min/max thermometers. They sound quite helpful.

      Don’t worry about those air bubbles. I use a small kraut pounder to pack my jars. Use your fist or any devise to just gently press the mixture in and the bubbles will rise to the surface. Leave your current jars be or feel free to press down on their contents now. Since it fermented so nicely, the air bubbles should pose no problem. Little or not risk of mold due to all the good bacteria and low pH.

  17. Hello Holly, I would like to say thank you so much for the amazing amount of info you put on this page! I have been researching my first step into fermenting and purchasing a crock. I have bounced around the idea of buying aPolish, German, 5 Litre, 10 Litre etc. Not being sure what to do, (I now learned from you, a 10 Litre would not be a good idea if I can’t filed it even half way when fermenting). I came across this website and learned so much, I think I know what I want to do now. I am trying to find a 5 Litre starter crock kit – most likely the Nik Schmitt kit (they have an English version website),but they may not ship to Singapore. We’ll see. It’s hard to find a company that will ship here. My question is, if I can get a crock sent here, and because it is tropical weather (average temperature this week is 31C/88F – we are almost on the equator), would the humidity, air pressure etc maybe effect the fermenting time/create mold? Any suggestions?
    Again, great content and work on this website. Thank you.

  18. Hi Holly,

    Excellent advice!

    Thank you so much for all your kind suggestions in your reply to me.

    I just purchase your excellent Surefire Sauerkraut ebook!

    Very happy.

    And, I took a suggestion from a fellow-Canadian from Montreal, on this commments page
    ‘a!’…….they suggested a crock supplier in Holland, Ren Bours – great response from them…they will ship to Singapore my first starter kit etc…great supplier thus far….unfortunately both Schmitt crock supplers never responded….but Bours did, with great info,suggestions etc.

    Now I await my crocks….and follow your recipes….

    At this moment I am watching your youtube interview with Sylvie…great interaction

    Ever thought of doing short videos for the internet on how to ferment and crock?

    Think about it.

    u could help a lot of crock newbies globally.



    • Good to hear you found a source for your crock. You’re not the first to have good things to say about Ren Bours. Glad he’s able to help.

      Short videos are in the works. Have to first finish my BIG Sauerkraut eBook and then onto fun how-to videos. Thank YOU for all your support. Let me know your favorite recipe from the Recipe eBook.

  19. Can I use my Harsch crocks for making apple cider vinegar? The Harsch crock uses a water moat to restrict the inward flow of air, and all the vinegar recipes I’ve read use a cheese cloth to keep out bugs but allowing a inward flow of air. So do I need to remove the water moat and lid, and replace it with a layer of cheese cloth?

  20. Hi Holly,

    I ordered a 20 litre crock but think it’s much bigger than my needs, are their any issues with too much empty space in the crock?
    Say if I only fill it half way, will that effect the end result?

    I bought the bigger one for when I want to do a large batch of cucumbers at one time, but when I do cabbage it will be much less.

    • The ideal is to fill that crock about 80% full to decrease air available for mold and yeasts to grow. Play around with it, but you will likely find that you are scooping mold off the surface, much like with an open crock. Buy a second, smaller one???

  21. Hi Holly,
    I am soon to start up a small business selling sauerkraut and other products at my local markets. I would love some advice on how to move from my small size fermentation to a larger scale. I have been using jars at home so far, I am not sure whether to move to crocks and which size or a stainless steel vessel? I am wanting to do at least 3 flavours, possibly 5, so I would need several vessels. I have been searching online to find pictures of commercial ferment companies, but haven’t found much. One that I did find looked like they used a stainless steel large stock pot and lid (like you would use on a stove), I don’t understand how they would weigh the cabbage down or how the bubbles would escape?
    Also, If you have any tips on sealing the jars etc when I would put it in the jars after it ferments? etc.
    Any advice is much appreciated to help me get to the next step.

    • Hello Charlie, It is so great that you are starting a sauerkraut business. Sandor Katz has a chapter “Considerations for Commercial Enterprises” in his Art of Fermentation book that is worth looking at. If you’re anywhere near Berkeley, CA. There is the Three Stone Hearth that sometimes does apprenticeships. They use water-sealed ceramic crocks kept on wheels. There is the Cultured Pickle Shop in Berkeley that I’ve seen videos on/talking about their setup.

      Personally, I would ferment in the water-sealed stoneware crocks. See how large your can get from Stone Creek Trading. Stainless steel can get quite expensive if you’re using a grade that won’t corrode under the acidic conditions. I would do an image search for “raw sauerkraut brands” and then research the companies you find. Good Luck!

      • Thanks Holly, I live in Queensland, Australia, so a little far to go to one of those workshops! Though they would be great.
        I think I will have a go with the crocks, if I invest in a few I can have a few flavours on the go.
        I’ll have a look out for that book too, thank you for the tip.


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