Last month we discussed the amazing health benefits of eating real (as opposed to store-bought, pasteurized) sauerkraut and other lactic acid fermented vegetables. This month we will talk about how to do it yourself at home.
UPDATE: Check out our new Jar Top Fermenter that solves all the challenges with mason jar fermentation described below and makes mason jars a fantastic option.
How It Works
Lactic acid fermentation works when beneficial bacteria produce lactic acid. When the lactic acid builds up to a certain level it kills off all other harmful bacteria, including the bacteria that cause food to decay. The lactic acid producing bacteria continue to thrive in this high acid environment. This is why they can also live in the high acid environment of the digestive system. Vegetables preserved in lactic acid will keep for many months, or even longer refrigerated.
Vegetables are sliced, diced or shredded and submerged in a brine solution made of chlorine free water and iodine free salt. The vegetables should be weighted down so they stay below the surface of the brine. A lactic acid forming bacteria culture is added. It is important for the vegetables to be oxygen free for the process to work, so keeping them submerged is critical. The brine will retard the growth of harmful bacteria that might be present for long enough for the lactic acid forming bacteria to lower the pH of the solution (acidifying it) to a pH of 4 or lower. Once that occurs, typically within about two or three days, the acid kills off any harmful bacteria. Without exposure to harmful bacteria or oxygen, the vegetables begin to ferment and acquire their characteristic sour flavor.
During the first week or two the vessel containing the brine and fermenting vegetables should be kept at room temperature then moved to a cooler location like a basement where it can stay for many weeks. The longer the vegetables steep the more flavorful they become. During the fermentation process, quite a bit of CO2 (carbon dioxide) is formed, so it is important that the vessel have a means for this gas buildup to escape.
In order to preserve vegetables through lactic acid fermentation, you need four basic ingredients:
- Vegetables Suitable for Fermentation – Cabbage is the classic choice, but most root vegetables are also good candidates. Radishes, turnips, yams, beets, onions, garlic, kohlrabi, and rutabaga all work well. Other non-root vegetables like small cucumbers, peppers, and cauliflower can also be fermented.
- Natural Salt – Iodine free sea salt, sea salt or real salt. Salt is added to water to form a brine solution that delays the decaying processes for long enough for the lactic acid bacteria to take hold. With experience, you can reduce the need for salt in the process, but starting out you should use salt as indicated.
- Water – Filtered or boiled to remove any chlorine. The fermenting process can only take place in an oxygen-free environment, so submerging the vegetables in the salt water brine is critical.
- Lactic Acid Bacteria Starter Culture – The traditional source for this bacteria culture is whey, which is fine unless you are a vegan. Below we will discuss both vegan and vegetarian approaches to your starter culture. There are some good commercial starter cultures available online, but they are an unnecessary expense. If you are a vegan watch the label closely, as we have yet to find one that isn’t derived from milk.
In addition to the basic ingredients above, you will likely want to add some spices. See below for some ideas.
You will need a knife to cut the vegetables, a potato masher or meat mallet to bruise the cabbage and large bowls. You will also need something to act as a weight to hold your vegetables below the surface of the brine. Something made of glass or ceramic that is well cleaned is ideal. In addition to the above, you will need a vessel in which to do the fermentation. Here are some options:
- Mason Jar – Mason jars are commonly used, but can be limiting for several reasons. The lid needs to be loose to allow the buildup of CO2 to escape, and it will be impossible to prevent oxygen from entering the space above the brine. You also lose some of the brine as vapor so you may need to top off with salt water. Best bet here is not to fill too high with vegetables. Fill not more than 80% and be sure there is plenty of brine covering. Keep an eye regularly to ensure that there is sufficient brine. The mason jar should also be kept in the dark for most of the process. The biggest challenge we have found with using mason jars is that they are limiting in terms of the quantity you can do in a single batch. You need three or four-quart mason jars to do a single head of cabbage. On the other hand, if you use a bowl or crock, you will probably end up transferring into mason jars for storage anyway. UPDATE: Check out our new Jar Top Fermenter that solves all the challenges with mason jar fermentation and makes mason jars a fantastic option.
- Ceramic Bowl – This is the method recommended by Ann Wigmore. It works well except for the surface of the brine is prone to grow mold and or film that needs to be skimmed off regularly. There are mold and yeast spores in the air that will inevitably land on the surface of the brine and begin to grow. Of course, the surface of the brine is in constant contact with oxygen in an open vessel, so care needs to be taken to keep the brine levels substantially high. You can mitigate the air exposure with cling film.
- Purpose Built Fermenting Crock Pots – Gairtopf, a German company, manufactures two different designs of fermenting crock pots that are made specifically for lactic acid fermentation. While these certainly carry a cost (starting at $129 with free shipping for the smallest 5-liter capacity crock) they eliminate the drawbacks of mason jars or open bowls. They will do up to 50 liters at once, they have an innovative water seal that covers the brine and allows CO2 to displace all the O2 in the air space. The clever water seal allows excess air to escape and prevents oxygen from coming in. It is made of ceramic that doesn’t absorb odors, blocks light, is easy to clean and has a lead-free glaze. It also comes with specially designed weighting stones to keep the vegetables below the surface of the brine. Because the enclosure is oxygen free and covered, you should not see any film or mold that can build up in both the mason jar and open bowl approaches. It is as close to maintenance free as you can get. The only thing you need to watch is that water will evaporate from the water seal, and may need to be topped off occasionally. The key benefit of these fermenting crocks is volume. You can do larger amounts that are awkward with other vessels. We carry the Nik Schmitt designed crocks. It is basically the same as the Harsch designed crock, with primarily cosmetic differences, and the Nik Schmitt Crocks are often a little cheaper. Both Crocks are manufactured by Gairtopf in Germany. If you prefer the Harsch, you can find them on Amazon.
Vegetarian Vs. Vegan Approaches
One of the critical ingredients is a culture of lactic acid forming beneficial bacteria. These bacteria are replete in milk products like kefir, buttermilk, yogurt and sour milk. If you are vegetarian okay with dairy, these are a suitable source for a starter culture. Take a pint or two of buttermilk and strain it with a strainer lined with cheese cloth to separate out the whey. Add the whey to the brine and you are good to go.
But what if you are vegan? Not to fear! Lactic acid bacteria are common to milk products, but not exclusive to them. In fact lactic acid forming bacteria are common on the surface of fruits and vegetables, so it’s possible to start fermenting without any sort of dairy derived culture. The white powdery film on fruit like plums and grapes is the salts left over from the action of lactic acid forming bacteria that live on the surface of the fruit.
The trick is using an approach called “wild fermentation,” which means fermenting without a starter culture. Green cabbage is particularly high in naturally occurring lactic acid forming bacteria, especially organically grown cabbage that is free of pesticides. Cabbage is so high in these bacteria in fact that it is really the best vegetable that you can reliably ferment without any additional culture as a starter. Cabbage in appropriate salt water brine will develop its own beneficial lactic acid culture in time to carry off a successful batch. If you are just starting to ferment, just make sure that your first batch is a good, dense green cabbage. Don’t worry about adding whey or any type of starter culture. It will develop naturally. Once you have your first batch of sauerkraut, save the juice. A pint or two saved in a sealed container in the refrigerator can act as your “lactic acid starter”. It is the same principle as sourdough starter (another type of fermented food, BTW). Save some juice from the last batch to use as a starter in the next batch. Your next batch need not contain cabbage as the starter from your previous batch will do the trick. Voilà! 100% vegan lactic acid culture! Here are some tips to follow on your first wild fermented batch:
- Make sure that the bulk of what you ferment is green cabbage, if not exclusively green cabbage.
- Peel the outer leaves off and rinse, but do not rinse the interior leaves, before or after shredding.
- Give shredded leaves an extra good pounding. You want to squeeze plenty of juice from the cabbage to include in the brine.
- Puree one of the outer leaves in a little water to add to the brine.
- Use the recommended full measure of salt, especially on this first batch. The salt acts as a bridge to allow the lactic acid forming bacteria time to take hold. This is especially important when fermenting this first batch without a starter.
- Carefully examine your first batch when it’s done. Watch for signs of rot, sliminess or uncharacteristic odor. The presence of any indicates that the lactic acid didn’t reach critical mass in time, and you should discard the spoiled batch and start again.
- A successful batch will carry the unmistakable, pungent sauerkraut smell.
- If your first batch fails, include a little lemon juice or vinegar to increase the initial acidity of the brine as an additional help on your next try.
Basic Sauerkraut – Step By Step
- Take two heads of cabbage and remove the outer leaves and set them aside.
- Shred the cabbage into large plastic bowls.
- Use a kraut pounder or meat mallet to mash and bruise the cabbage. You should soften up the cabbage so that there is plenty of juice.
- Option: Mix in some spices to your shredded cabbage to spice up the sauerkraut. Try some dill (fresh or ground) caraway seeds, basil, juniper berries, black peppercorns, garlic, or experiment with combinations.
- Pack the cabbage into your fermenting vessel.
- Rinse the outer leaves and use one or more outer leaves to cover the shredded cabbage. Tuck the edges down. This will keep stray floaters to a minimum. Option: puree one outer cabbage leaf in a little water and add to your brine, especially if you are fermenting without a starter culture.
- Use a weight to weight down the cabbage. A ceramic cup or dish (well cleaned) will serve.
- Make brine with filtered water and iodine free salt. Use a ratio of 1 tablespoon of salt to a quart of water. Pour into vessel so the brine covers the cabbage by an inch or more.
- Strain a pint or two of buttermilk through a cheesecloth lined strainer. Add the whey to the brine. Option: skip this step if fermenting wild.
- Let your vessel sit for about a week at room temperature.
- Move the vessel to a cooler location like a cool basement or even the refrigerator.
- The sauerkraut should be ready after another week. Fermenting it for longer periods will result in a more flavorful and softer sauerkraut. It will keep in the refrigerator for many months.
- Check For Failed Batch – Watch for signs of slimy sauerkraut, obvious rot or uncharacteristic or foul odors. Discard the batch and try again if any are present.
- Don’t Disturb – If you are using a fermenting crock pot resist the temptation to peek or uncover. As it will introduce oxygen and spores from the air.
- Starter Juice – Save the juice from a successful batch to use as the starter culture in your next batch.
- Skim the Scum – If using mason jars or a ceramic bowl, you will need to monitor frequently to skim any film, scum or mold from the surface of the water. Allowing this to build up too much can spoil a batch or introduce an unpleasant flavor. A successful batch in a fermenting crock pot should not have any film or mold.
Things To Try
- Less Salt – Once you get a little experience you can experiment with reducing (or even eliminating) salt from the process. Make sure you have plenty of starter culture to jump start the process, and use the juice from freshly juiced celery (which is high in natural sodium) to take the place of salt. The more celery juice you use, the less salt you can use.
- Spices – Experiment will all kinds of flavoring and spices. In addition to the spices mentioned above (basil, dill, caraway, peppercorns, garlic, bay leaves, juniper berries) also experiment with mustard, wasabi, horseradish, sage, rosemary, thyme or oregano. Use onion sparingly as a little goes a long way, and you can even add a kick by throwing in a slice or two of fresh jalapeno pepper.
If you are ready to try fermenting your own vegetables, we recommend taking a look at either of these books to learn more and get additional ideas and recipes:
While you can certainly succeed in fermenting vegetables in mason jars or ceramic bowls, a fermenting crock pot makes the process much easier and more successful. It also makes a smart addition to any emergency food storage program.
by Kaitlin Petra Jones
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