My last two columns on home fermentation triggered a surprising number of email questions from readers. In today's column, I'll address the three most commonly asked questions and pass on a couple new recipes.
How can I tell if it's safe to eat?
Fermentation is one of the oldest methods of food preservation. It's very safe as long as you adhere to some basic principles. The goal is to create an acidic environment that is too harsh for non-beneficial bacteria and molds. Pickling achieves this by adding vinegar.
Lacto-fermentation achieves this by salting and creating a brine that is ideal for lactic-acid-producing bacteria and inhospitable to other bad bacteria. Because lactic-acid bacteria are anaerobic, as long as the veggies are kept submerged "underwater," they are protected from the bad aerobic bacteria.
How do you know when your ferments are ready?
It's important to know when it's time to put your ferment into the fridge. It will continue to ferment while in cold storage, but much more slowly. It may take anywhere from three days to three weeks to get to that point of "doneness." There really isn't a set time frame. The only way to really gauge doneness is by tasting your fermented product. The moment you place your fruit or vegetables in a brine, the flavor starts moving from sweet to sour. As microorganisms continue to do their work on the sugars and other carbohydrates found in the vegetables, the taste of fermented vegetables will change. How quickly that transformation takes place is affected by several variables, such as room temperature and particle size – whether it's shredded like sauerkraut, cut in pieces like cauliflower, or kept whole like cucumber pickles.
If it's under-fermented, it will taste a bit raw, and if over-fermented, it will taste unpleasantly sour. The ideal degree of sourness is a matter of personal taste and intended use. Periodically sample your ferment to assess its progress. I recently made a jar of fermented red cabbage kraut with apple. When I first tasted it, it was almost perfect. I got busy and a week later, I planned to serve it with pork chops, but it had become a bit too sour. In Korean cuisine, when kimchi is served as a raw side dish, "young," somewhat under-fermented kimchi is preferred. For use in a soup or stew such as kimchi jigae, over-fermented, stronger tasting kimchi is better. One of my favorite "junk food" indulgences is a Kogi Dog – a grilled hot dog on a toasted bun spread with sesame mayo, caramelized kimchi, grated cheddar, and topped with lime-cilantro-scallion slaw and a swiggle of Sriracha. It's so damn tasty! For Kogi Dogs, you want to use your oldest, funkiest kimchi. When you begin sauteeing the kimchi in butter, it smells pretty vile. But after it caramelizes down, it becomes unctuous, sweet, divine.
What do you do if there's mold floating on top of your jars? Do I need to throw it out?
This happens when something has floated to the top and is no longer submerged in the protective, salty, oxygen-free environment. That's the reason you want to put a weight or brine-filled zip-close bag to keep whatever you're fermenting underwater.
If you find a white film or colored, raised fuzzy spots on top of your ferment, carefully spoon off the top layer, give the container a few seconds to air out, then evaluate the aroma and flavor. If it doesn't smell foul, taste it. If it doesn't taste bad, it should be fine. If it smells or tastes unpleasant to you, dump it and try again with a new batch.
When you are ready to venture further in your home fermentation journey, try making this delicious and anti-inflammatory celery kvass from St. Louis food writer Sherrie Castellano. Or a crazy interesting Jalapeño Cilantro Lime Kraut from Farmsteady.
Adapted from a recipe by Sherrie Castellano
½ lb celery, stalks and leaves
½ tsp fennel seeds
1 bay leaf
¼ cup parsley leaves
1 teaspoon whole black peppercorns
¼ teaspoon uniodized salt*
3 cups distilled or filtered water*
*if you have a kitchen scale, use 14 grams of salt and 710 grams water
Cut the celery stalks into pieces no longer than 5 inches and save the leaves. Add the fennel seeds, bay leaf, parsley and peppercorns to a wide-mouth quart canning jar. Rinse and drain the stalks and leaves and pack tightly into the jar. Dissolve the salt in the water and fill the jar, allowing at least 1 inch between the waterline and the top of the jar. If the celery and leaves won't stay submerged, use a fermentation weight or brine-filled resealable bag to hold them down. Seal jar with a lid with an air lock and set on a plate at room temperature for 5 days. If you don't have the fancy lids, use a regular canning lid and open slightly every so often to release the built-up gases.
Strain the liquid into a clean jar and chill before drinking. The fermented celery can be used in salads or soups and stews.
Jalapeño Cilantro Lime Kraut
Recipe courtesy of farmsteady.com
1 head Napa cabbage
1 1/2 tablespoons kosher salt
2 jalapeños, thinly sliced
1/2 cup cilantro, chopped
1/2 lime peel, thinly sliced
Remove and discard any outer damaged or wilted leaves from the cabbage. Reserve one large leaf. Quarter the cabbage and remove the core. Cut each quarter crosswise into 2-inch-wide strips. Regular green cabbage works great in this recipe as well but should be thinly sliced.
In a large mixing bowl, combine your shredded cabbage and salt. Massage the salt into your cabbage for 8-10 minutes. The cabbage will soften and release liquid. Add in jalapeños, cilantro and lime peel. Toss to combine.
Pack the cabbage into your fermentation jar tightly, using your hands and pressing down with your fist. Add all liquid released from the cabbage.
Trim the reserved cabbage leaf into a circle (you can use the base of the jar or the lid as a guide). Place on top of the packed cabbage and then add the fermentation weight. You want the packed cabbage to be completely submerged when weighted. If liquid levels are low you can top with a brine by dissolving 1 teaspoon salt to 1 cup water.
Top with lid and airlock. Ferment 5 days, then refrigerate.
Peter's pandemic hiatus is over and he is now at the restaurant Spoon and Stable in Minneapolis, baking bread and making pasta. If you have any more questions about home fermentation, he can be contacted at email@example.com.