Warning! This topic is NOT complicated, but it does have different parts, because some types of foods are fermented in one way, some in another way, and a few can be done in more than one way. So we’ll try to cover the basics in as simple a manner as possible.
Fermenting foods introduces healthy microbes into the food, which sometimes preserves the food for an extended period, but sometimes is done for reasons other than preservation. The microbes consist of an assortment of bacteria and yeasts. When it is done properly, the healthy ones grow faster than unhealthy ones and keep the unhealthy ones from populating significantly. For more on good and bad microbes, read this article: Good Germs, Bad Germs
Other terms commonly used for fermented foods include:
- Cultured
- Cured
- Pickled
- Brined
We do NOT advocate or provide information on making alcoholic drinks – we do provide information on not ACCIDENTALLY making such foods!
Commonly fermented foods include:
- Sauer Kraut
- Pickles (old fashioned brined pickles do not use vinegar)
- Vinegar
- Milk cultures such as kefir, buttermilk, and yogurt
- Salsa
- Mustard
- Ketchup
- Many types of condiments
- Bread yeasts (including wild yeast made without store bought yeast)
- Hummus and other bean ferments
Many of these are traditionally fermented foods. Most fermented foods end up with a pickled flavor, and may taste like they contain vinegar even when they do not.
Most fermented foods follow a basic set of processes and rules:
1. Use clean containers and utensils, and clean your produce with water (vegetable detergents are not helpful).
2. Prepare the food – peel, chop, crush, mix items together, etc. WARNING: If the food has spoiled bits on it, soft spots, or other signs of decay, do not use it. You need fresh food with no signs of mold or rotting, or you’ll spoil your ferment before it even gets started.
3. Either pack it into the jar so there are no air bubbles, or submerge the food in salt brine. Exception: wild sourdough yeast is simply mixed in a jar.
4. Solid foods that do not have liquid above the surface should be close fermented with a lid on the jar. Brined foods may be open or close fermented (closed fermenting may take a little more attention if you don’t use an airlock system). Vinegar and wild yeast requires open fermenting.
5. Leave plenty of headroom in the jar, so the food has room to expand. Foods will typically increase by 25-30%, but some increase as much as 50% in the fermentation process.
6. During the initial fermentation period, make sure the food stays under the surface of the liquid if it is a brined food (use something to hold it under the brine if needed – a zip bag filled with water works if you don’t have anything else the right size, though we recommend using a double layer of zip bags with a bag full of water sealed inside a second bag just in case it pops open).
7. DON’T MESS WITH IT! Leave it alone and don’t stir it, don’t open the cap, don’t repack it, just leave it alone for at least 3-5 days (or however long the recipe calls for).
Exception #1: Non-airlock close fermented containers should be vented as needed. This does NOT mean opening the top! It means loosening the lid until you hear it hiss, and tightening it back a little when it stops hissing. The top of a canning jar lid won’t pop down when pushed if it needs vented.
Exception #2: If you are making sourdough starter or Amish Cinnamon Bread starter, then you need tend to it as directed in your instructions. If you are making wild yeast, it is important to open it and stir it daily during the initial fermentation period to help with the propagation of wild yeast in the starter. That is not important once it gets going.
NOTE: During the beginning of the process, the ferment won’t have much odor, but by the second or third day, you should start to smell a vinegary, pickley smell. If it lacks that smell, after four or five days, and especially if the water has gone unevenly cloudy (iodized salt may cause a little bit of even opacity to the water, this is more clumpy looking), or if the vegetables have started to feel slimy, throw it out. This isn’t likely to happen if you follow the directions, but the best of us push the limits sometimes and find out the hard way just where they are!
8. When the food has reached the desired degree of fermentation, it may be repacked into a clean storage container with a tight lid. Make sure that you still follow the rules of working out air bubbles, and submerging brined foods in brine. The jar should be fairly full. Store the container in a cool, dark place – a refrigerator is good, or a cool root cellar.
9. During storage, DON’T FUSS WITH IT! If you need to remove some to use it, do so, but don’t mess with it a lot, and submerge the foods again, and reapply the lid, tightly.
10. Make sure you clean your hands before getting foods out, and use clean utensils. It can be really difficult to keep the kids from getting into the pickle jar with their fingers, but it helps the food last longer!
11. Use your eyes, and your nose. If something does not look or smell like food, don’t eat it. Throw it away instead. Don’t try to salvage it. Your compost will appreciate it, but your stomach probably won’t.
Some foods do require specific temperatures to incubate cultures, but most pickled foods do not. Some won’t do well in summer heat – in fact most don’t, though you can culture yogurt in the summer without an external heat source if you live in a warm climate. Most pickled items were fermented in a root cellar in previous centuries, where the temperatures were fairly cool, allowing for a long slow ferment. A root cellar is typically warmer than a fridge, but cooler than room temp, and many ferments thrive in that range. The top of the fridge provides a warmer place to culture foods that like a little extra warmth in the winter time. Pay attention to the way your recipe says to do it, and find a spot that meets the general requirements.
Fermenting foods can be a lot of fun. There’s a real thrill in biting into a pickle that started out with a few simple ingredients, and turned into something that does not taste like any of the ingredients you put in, but which is simply delicious. Fresh cultured foods are not like the embalmed grocery store versions, they are crisp and lively in flavor and texture.
So follow the rules to enjoy healthy fermented foods. And have some fun with it!