Fermented Foods


History

Lactic Acid Fermentation (commonly referred to as lacto-fermentation), is an ancient method of preserving food primarily using the Lactobacillus genus of bacteria. Many different cultures have their own cultural food or drink made using lacto-fermentation; in Africa they make Koko Sour Water, in Mongolia and the Caucasus mountains they make Kefir, in Europe there is sauerkraut and pickles, and in Korea and China you find Kimchi. It uses the preservative nature of lactic acid and salt to prolong foods consumability. Many different foods can be preserved via lacto-fermentation including:

  • Dairy

  • Fruits and Vegetables

  • Beverages

  • Meats and Fish

Science

Lactic acid fermentation primarily uses the Lactobacillus genus of bacteria. Despite this, many fermentations also include other genus of bacteria and yeast including Brettanomyces, Pediococcus, and Leuconostoc.

Name Yeast Anaerobic Bacteria Produce Lactic Acid Produce Slime Other Notes
Lactobacillus x x Common in nature
Brettanomyces x Found on skins of fruits. Known colloquially as “Brett.”
Pediococcus x x x
Leuconostoc x sometimes x Responsible for the “sour” smell in sourdough bread.
Streptococcus thermophilus x x Found in yogurt and sour cream.
“Kefir Grains” x x x Symbiotic colonies of yeast and bacteria in a matrix of lipids and proteins

Brine Method:

Many methods for pickling rely on a brine (salt water) solution to inhibit initial microbial growth until Leuconostoc, Lactobacillus, Pediococcus, and other beneficial microbes can sufficiently reproduce and begin fermentation. The fermentation process of these microbes causes a lowering of the pH, due to lactic acid production, in the overall solution and further inhibits the growth of unwanted microbes. The process can take a few days to several months at room temperature (around 72°F). The finished pickles can then be stored at cellar temperature or in the refrigerator and be enjoyed for months or years longer than the original fresh produce.

...which leads us to…

TASTY PICKLED FOOD!

Yogurt and Dairy Ferments:

Yogurt, sour cream, kefir, and cheese are all fermented foods that are made from dairy, sheep, or goat milk. Yogurt relies on a rather simple process by which to make it. You first heat the milk to around 185°F which denatures the protein in the milk, preventing the milk from forming curds. The milk is then cooled to around 110-115°F at which point the bacterial cultures are added. Yogurt is a quick ferment if kept above 100°F during the entire fermentation process. The quick process results in it being finished with fermentation in around 6-12 hours. Sour cream uses almost the same process, but is instead fermented at room temperature and using heavy cream.

...which leads us to...

TASTY YOGURT!

Fermentation Vessels

An appropriate vessel for making pickles is one that is:

  • Airtight

  • Food-safe

Mason Jar

  • Glass is easy to sanitize

  • Inexpensive

  • Airtight so no oxygen gets in from the outside

  • Special lids allow for use of airlock.

Pickle Pot

  • Generally made of earthenware or ceramic

  • “sealed” with water and allows gasses to escape during fermentation

Fermentation bucket

  • Made of plastic

  • Available in 2 gallon and 5 gallon sizes

  • Airlock encourages gasses to escape

  • Difficult to sanitize completely. Do not use same vessel for pickling and then making beer or mead.

(Wide-Mouth) Vacuum Flask:

  • Keeps temperature consistent for yogurt

  • Wide-mouth helps with removal and cleaning later on

Generic Procedures For Pickles

Step 1: Gather ingredients.

  • Fermenting Vessel

  • Sanitizing agent such as Star-San

  • Sea Salt (non-iodine containing salt)

  • Chosen produce

  • Filtered Water to cover (if needed)

  • Weights (if needed--to keep vegetables submerged)

Step 2: Sanitize vessel and prepare produce.

  • Sanitize vessel, spoons, and weights according to directions. If using Iodophor, you must let it dry completely.

  • Wash produce in filtered water, but do not cook or sanitize them.

  • Chop produce into desired size

  • Add salt to chopped produce or create brine solution of about 2% salt and add produce to it.

    • Brine solutions are about 3 Tbsp salt to 1 Qt water, depending on the type of salt.

  • Add any additional spices at this time.

  • Make sure all ingredients are submerged below the brine. Push out any air pockets or bubbles.

  • Leave an inch or two of space between the top of the brine and the top of the vessel

Step 3: Close vessel and wait.

  • Leave at room temperature, out of direct sunlight.

  • Check after a few days.

Good:

  • Sour “pickle” smell

  • Bubbles of CO2/burping

  • Cloudiness in Brine

  • Bubbly/carbonated flavor

Okay:

  • White film looking a little like spaghetti known as kahm yeast--just scrape it off, it won’t kill you.

  • Foam should disappear after a few days.

Bad:

  • Bright colored molds

  • Fuzzy black molds

  • Funky “off” or “putrid” smell

  • Slimy Brine

Plain Sauerkraut Recipe

There are many methods for making sauerkraut, this is just the method that I use.

Ingredients:

Kosher salt (or sea salt, it just must not include iodine)

One head cabbage

Mason jar (1 quart size jar is good for about ½ a cabbage)

Star-san (This is preferable, if you are using Iodophor you must rinse extremely well)

Saran wrap

Instructions:

  1. Wash the head of cabbage removing several layers of outer leaves.

    • Set aside one large leaf for later.
  2. Weight the remaining cabbage in grams, note this for later.

  3. Chop up the cabbage into smallish pieces.

  4. Set aside 2.25-2.5% by weight of Kosher Salt.

  5. Knead the salt into the cabbage, squeezing the cabbage and working > the salt into all of it.

  6. Set aside for 20 minutes, covered with saran wrap.

    • At this point, you should sanitize the mason jar.
  7. Put the cabbage into the mason jar, pour the liquid over the cabbage > ensuring that the cabbage is completely covered by liquid.

  8. Place the large cabbage leaf of the top of the cabbage, ensuring it > too is covered by the liquid.

  9. Lightly screw the mason jar top on, set aside for as long as you > like based on taste.

  • If the cabbage raises out of the liquid due to CO~2~ push it down > with a sanitized wooden spoon.

Dill Pickle Recipe

This is a standard lacto-fermented dill pickle recipe that I have modified.

Ingredients:

5 tablespoons kosher salt (or sea salt, it must not contain iodine)

2 quarts filtered water

4-6 grape leaves (optional)

6-9 cloves garlic, peeled and whole

2 large heads of dill

A pinch of black peppercorns and red pepper flakes. (You can include mustard seeds, I however do not)

Pickling cucumbers

Star-san

Optional: sliced carrots and other vegetables

Instructions:

  1. Mix the water and salt into a brine solution.

  2. Add a few of the leaves and some of the spices to the bottom of the > jar.

  3. Add some of the cucumbers.

  4. Layer more leaves and spices until the jar is full about 1-2” from > the top of the jar.

  5. Pour the brine solution over all of the mixture leaving 1” of > headspace in the jar.

  6. Lightly close the lid of the jar and leave for 3-5 days, or to > taste.

Further Reading and Resources

[1] “Lactobacillus.” Wikipedia. Wikimedia Foundation. Web. 29 Apr. 2015. <http://en.wikipedia.org/wiki/Lactobacillus>.

[2] Katz, Sandor Ellix, and Michael Pollan. The Art of Fermentation: An In-depth Exploration of Essential Concepts and Processes from around the World. Print.

[3] Tonsmeire, Michael. American Sour Beers: Innovative Techniques for Mixed Fermentations. Print.

[4] Garrett, R, and Charles M. Grisham. Biochemistry. Belmont, CA: Thomson Brooks/Cole, 2005. Print.

[5] Lei, V, and M Jakobsen. “Microbiological Characterization and Probiotic Potential of koko and koko Sour Water, African Spontaneously Fermented Millet Porridge and Drink.” Journal of Applied Microbiology. 96.2 (2004): 384-397. Print


See also