Spring Fermentation

Regular readers of my articles know I am interested in food preservation and the minimization of waste. Thus, it should come as no surprise to learn that I’ve delved into more than a few fermentation projects. As I think of the spring crops coming on, my mind drifts immediately to lactobacillales, one of humanity’s oldest friends.

I recently started making kimchi again when I saw some Napa cabbage that was on its way to becoming pig food. I did some research (it had been a number of years), grabbed a food-safe bucket and some ingredients, and got to work. I won’t go into detail (I’ll save that for the fall), but suffice to say my interest in lacto-fermentation was rekindled.

Lactobacillus is a bacteria. It digests sugars and converts them into lactic acid, which produces tart, fruity, funky, and umami flavors. Sour pickles, sauerkraut, sourdough bread, yogurt, and sour beers all rely on lacto-fermentation. To a lesser extent, so do wines, many cheeses, cured sausages, and miso. Lactic acid bacteria are anaerobic, meaning they can flourish without oxygen, and they are highly salt and acid tolerant. There are an untold number of strains, each producing its own nuances of flavor. And they are everywhere.

Back to the season at hand, here in the lush and fecund Skagit Valley, we are blessed with an abundance of early radishes, turnips, and asparagus. These veggies have all the hallmarks that you look for in a pickle. Crisp, not too fibrous, juicy, fresh, and delicious. With just a little preparation, the process is a breeze. The hardest part is waiting.

Rather than a recipe, let’s just talk through the basics. I’d advise starting simple: One kind of vegetable, maybe one or two aromatics or spices, salt, water, lactobacillales. The first thing to do though is figure out what to ferment in.

Setting up a fermenting vessel can seem challenging. There are airlocks, ceramic crocks, fermenting weights, jar attachments, sealed fermenting bags, and many other implements available. The beauty of lactic fermentation is that it’s very forgiving. Find a food-safe container that you can more or less seal, and find a ceramic plate or bowl that fits in snugly. Add weights—clean marbles or stones are fine—to press the solid contents underneath the liquid.

There are a few simple rules:

1. Clean your crock and equipment thoroughly.

2. Use filtered or spring water—never tap or distilled water.

3. Use enough salt.

4. Keep everything submerged.

Second, wash your ingredients, but NOT TOO MUCH. We aren’t inoculating the brine, we’re relying on naturally occurring bacteria in the environment. Most of this comes from the produce itself. Run the vegetables briefly under cool water and get rid of any dirt. Trim the greens off of turnips and radishes. You can leave them whole, but it will take longer to ferment. Otherwise, trim the ends off and slice into ¼ to 1/3 inch rounds. For asparagus, trim the bottom and try to pull off the thickest of the fibers. You can cut the spears in half or leave them whole. I’ll also give a quick shout-out to the next round of vegetables that will be in season: raab, garlic and leek scapes, spring onions, and spring garlic are all excellent lacto-fermenting foods.

Next, what are other ingredients you’d like to use? Delicate herbs don’t work well, nor do powdered spices. Garlic, onions, ginger, peppercorns, mustard seeds, rosemary, or bay leaves are fine add-ins. As I said earlier, start simple. With such delicate and fresh produce, there’s a lot to be said for leaving it entirely plain. The fermentation alone produces an abundance of flavor.

Find a bowl or other container that will easily contain all of the vegetables. Weigh it while empty, and make a note of the weight. Add all of the vegetables, cover completely with water, and weigh again. Calculate 2% of the weight of the vegetables and water, and measure out that much salt (non-iodized!). Drain the water off into another bowl, and dissolve the salt into it. Put the vegetables into your fermenting vessel and then add your dish and weights. Pour the brine over. Press the weighted dish down to make sure everything is submerged, and close it up. Don’t seal it entirely, you don’t want it to explode. You can use an airlock, a not-quitetightly screwed-on jar lid, or a food-safe bucket with a lid. As long as the contents are submerged there’s very little possibility for contamination. It should be kept at 55° to 75° for a minimum of four days, and typically not more than seven. The best way to know when something is done fermenting is to taste it, so crack it open after four days and see what’s happening. Is it soft enough for you? Is it funky enough? Call it done when you want, and then call your friends. Tell them to bring jars.