Sauerkraut Fermenting: Cooking with Microbes

Recipe is from Fermenting Certification course with Harvard

Recipe Ingredients:

• ½ Cabbage (red or green or a mix of both)

• Salt, 2 -3 % of cabbage weight

Optional Spice Additions:

• Caraway seeds, garlic, allspice, black pepper, chili flakes, cumin, turmeric, mustard seeds

Materials:
 

• Wide mouth quart mason jar with lid

• Cutting board

• Knife

• Large bowl

• Food Grade pH strips

• Clean paper towels/cheesecloth (optional)

• Rubber band (optional)

Procedure:

1. Chop cabbage finely. Weigh the cabbage, place it in a large bowl, and sprinkle salt on the cabbage. Distribute salt evenly throughout the chopped cabbage.

1. Massage the cabbage mix to break up the structure and help release the water. The salt pulls out water from the cabbage through osmosis. You want to really squeeze and knead the cabbage for at least 5-10 minutes.The cabbage should ‘sweat’ and release a substantial amount of brine. Tilt the bowl and pull the cabbage aside to see if you have brine on the bottom of the bowl. When you have about a cup of brine, you are done.

1. Measure the pH of the cabbage brine. Place the cabbage mix into the mason jar. Do this by adding a little cabbage at a time and pack tightly with your fist or a kitchen utensil (a pestle or spoon is great!), pushing all the air out, before adding more cabbage. When you are done, the brine should cover the cabbage completely. If it doesn’t, make sure the cabbage is pushed down tightly – the cabbage will sweat more water in the next few hours.  (If for some reason your salted cabbage does not make enough brine, then simply add 2-3% ratio of salted water on top, to keep the cabbage fully submerged when pushed down)

1. Fold several whole cabbage leaves and place on top, again pushing down tightly. They will serve as a lid, and you can peel off one at a time if mold develops. Pro Tip: Use a glass weight that fits your jar, or a plastic zip-lock filled with water to weigh down the kraut to keep it below the brine water.

1. Place the lid on top but DON’T tighten it – gas will be produced which can cause the jar to explode if the gas can’t escape. If you use a lid remember to check daily that the lid remains very loose and make sure to let any air out – when we do this, we say that we “burp” the sauerkraut. An alternative to using a lid is to cover with a clean paper towel or a doubled-up cheese cheesecloth secured with a rubber band. Place the jar on a shallow tray or in a large bowl to catch any brine that may bubble out when the fermentation gets going.

1. Leave to ferment for 1-3 weeks in a constant environment of 70 to 75 degrees F (Use an incubator or a heated water bath cooler with an aquarium heater if room temperature doesn’t stay constant for you). Check often for mold on top and remove the top cabbage leaves if this occurs. This is common and if removed right away, the sauerkraut underneath will still be fine to eat. Properly fermented should be measured at a pH of 3.5 or lower.