Straight to the Point
For fermenting at home, we recommend investing in a scale, canning jars, air locks, fermentation weights, a fermentation crock, pH strips and a meter, and glass bottles. You can read more about our recommendations below.
Fermentation is a gear-heavy business. (Take that from a home-fermenter whose kitchen is bursting at the seams with all kinds of jars, valves, lids, and various knickknacks.) Whether you’re making kimchi, dipping your toes into sourdough (not literally, hopefully), or brewing your tenth batch of amber beer, you’re going to benefit from having the proper equipment. As one of my old chefs used to say, you gotta use the right tool for the right job.
If you're just starting out, the tools required are relatively spartan—especially for recipes like sauerkraut or dill pickles. But as you progress into more complex techniques and refine your methods, that toolkit will expand. Let’s dig in.
A Reliable Kitchen Scale
Fermentation relies on spontaneous interactions between microbes and food: in other words, it’s a game of chance—based on probability and the conditions you supply. Still, one of the main goals of any fermentation recipe should be reproducibility. Can you get the same or a similar result, every time? That’s where a kitchen scale comes in handy. Since many recipes feature a specific ratio of salt to solid material, a kitchen scale makes it easy to double, triple, halve, or even multiply a recipe by any factor. For instance, recipes like sauerkraut often use a 2% brine. Using a scale, you can prepare a 2% solution of any volume of water to accommodate however much cabbage you’re using. Without a kitchen scale, that kind of flexibility, precision, and consistency would be virtually impossible
Glass Canning Jars (Of Various Sizes)
8-Ounce Mason Jars
This size is ideal for smaller projects or test batches for those who don’t want to commit to a large yield. They’re also great for managing and maintaining a sourdough starter over a long period of time.
16-Ounce Mason Jars
This size is suited to smaller batches of material, or for test batches. The yield is generally under two cups, so it’s great for small households.
32-Ounce Mason Jars
A quart-sized jar is perfect for most fermentation recipes like hot sauce or a smaller batch of pickles. This is probably one of the most versatile sizes, and its wider mouth makes it easier to go in and out of the jar with chunkier items.
Half-Gallon and 1-Gallon Jars
While a jar can get you far, there are two potential concerns for particularly active ferments. First, there can be a large buildup of carbon dioxide, which requires unscrewing the lid periodically or “burping” the jar. Second, there is always potential for the unwanted growth on any surface exposed to oxygen. For example, though technically harmless, kahm yeast—the fuzzy, white, musty-smelling substance that accumulates on the surface of a batch of pickles—is a common concern for many ferments because it can adversely affect overall flavor. To get around burping, and to guarantee (or at least raise the chances of) an anaerobic environment, it’s helpful to use an air lock.
An airlock is any device with a one-way valve that allows carbon dioxide to escape the vessel; at the same time, the device prevents any oxygen from entering. As fermentation proceeds, carbon dioxide accumulates—replacing any oxygen in the vessel—and escapes, promoting an oxygen-free environment.
Air locks generally come in two types: Water-less, and water-based. Typically, these are specialized lids that fit most conventional canning jars. Water-less air locks like the Easy Fermenter lids, are great for projects like sauerkraut or kimchi. The set comes with a vacuum pump to initially remove oxygen. Over time, the one-way valve continues to keep oxygen from entering as carbon dioxide builds and escapes.
Water air locks offer practically the same functionality as water-less air locks. As the ferment produces gas and pressure builds up, gas will force its way through the valve and through the water chamber, finally making its way out through the pinhole in the top cap. Water-based air locks tend to offer more flexibility, since they can be fit to practically any sized jar.
As fermentation goes on, things tend to move around—especially if they’re bubbling in a brine or any amount of moisture. Solids can float to the surface and can be exposed to air (especially if you don’t use an air lock), which isn’t ideal. A simple solution? Drop a weight on top. Glass weights come in various diameters, and they’re perfect for keeping items submerged in liquid. I don’t recommend metal, wooden, or other potentially porous materials for weights.
For larger projects like miso or soy sauce, any recipe that features a mash, or even certain pickle recipes, stone weights are another great option to keep the solids submerged. These stones from Ohio Stoneware are a textbook example: They are non-porous, ceramic weights that measure six inches in diameter—ideal for large gallon jars or wide ceramic crocks.Continue to 5 of 7 below.
A Fermentation Crock
While glass jars are easy to find, affordable, and come in a range of sizes, there are some benefits to upgrading beyond a jar. Take this ceramic fermentation crock, for example. It's heavy-duty and dark, offering a cool, dark space that is impervious to light, which can adversely affect fermentation. Longer-term fermentations like miso or soy sauce can benefit from using these types of crocks, since you don’t have to monitor for light exposure or worry about massive fluctuations in temperature. This crock comes with its own weights to keep your ingredients in their brine and a little muddler, for fermenting mashes. It also comes with its own built-in water valve—and everything is dishwasher-safe.
The team also likes this Korean fermentation crock, which is made of BPA-free plastic and is dishwasher- and even microwave-safe (though we don’t advise microwaving in a fermentation recipe). These crocks come in a wide assortment of sizes, whether you're making just a small batch of pickles or a massive container of kimchi. You won't need any weights with this model either—simply press down on the lid to keep your ingredients submerged.
pH Strips and pH Meters
One way to know if your foods are properly fermented is by testing pH. The FDA recommends that acidified foods have a pH of 4.6 or lower; but for a truly shelf stable item like hot sauce, you’ll want an even lower pH of 3.4 or below. (pH ranges from one to 14; one being the most acidic.) To test the pH, pick up some test strips or a pH meter. Christina Ward, our contributor who has written for us extensively about pickle science loves this digital pH meter, which takes you out to the hundredths. While it might feel like overkill, this kind of accuracy will ensure your fermented foods are safe to eat.
Thick Walled, Round Glass Bottles (Optional)
While by no means an essential piece of equipment, a glass bottle comes in handy when you’re making beverages like kombucha, ginger soda, beer, or cider. These bottles are designed to trap carbon dioxide via a tight-fitting cap: as yeast consumes sugar, it produces gas that carbonates the beverage. Swing-top or “Grolsch” style bottles are a popular choice among home brewers, since they are sturdy, easy to clean, and the gaskets last for quite a long time.
One drawback to swing-top bottles is that they are all-or-nothing: There’s no way to ease into opening the bottle, which means there is a risk of a small explosion if there’s a large buildup of carbon dioxide in the bottle. A great alternative is to use a twist-cap bottle such as these Stout Flint Glass Bottles. They feature threaded twist caps that form a tight seal when closed properly. Twisting allows you to let gas out slowly, which gives you a little more control.
Are Mason Jars fermentation-grade?
Yes, Mason jars are recommended for fermentation.
Do I need to burp my fermentation?
If you’re using glass jars, yes, you will have to periodically “burp” them. However, you could also invest in some air locks, as described above.