Fermentation is one of the oldest ways to preserve food, but it’s a technique that has become unfamiliar for modern home cooks. We still consume a lot of fermented foods, including dairy and grains, and we may even be brave enough to try those at home. But somehow fermenting vegetables seems daunting, raising doubts about whether we’re preserving or spoiling food.

Essentially, fermenting is souring via microbes. Microorganisms break down the sugars and carbohydrates in food, causing a chemical change that increases acidity and ultimately preserves the food. The process leaves no room for microbes that spoil food to move in. Properly fermented food looks, smells, and tastes bright, crisp, and tangy. A fermentation that has problems will be discolored, soft, and rotten smelling; you’ll turn up your nose before it even gets near your tongue.

Most people think of pickled cucumbers or brined cabbage when they think of fermented vegetables. But many other vegetables, and even some fruits, can be fermented. In most cases, the only ingredients needed are fresh produce, salt, and water.

Fermenting produce is far simpler than making cheese, baking bread, or even canning vinegar-pickled vegetables. If you have the space to store them (we reinforced the shelves in the fridge because they become so loaded with jars of fermented vegetables), you’ll quickly fall in love with pickles that stay crisp because they’re never exposed to heat and turn sour naturally instead of tasting of vinegar. As I share some of my favorite vegetable ferments this month, keep a few points in mind to ensure your ferments are as successful as mine.

Preserve the Best

As with any preservation method, starting with fresh, unblemished produce gives the best results. The good microbes in vegetables that have started to decompose fight an uphill battle against spoilage microbes. If your produce has been damaged by garden pests or weather, you may still be able to cut away the rough spots and ferment the rest.

A clean fermenting vessel and fresh brine also keep the process running smoothly. Scrub any dirt from your vegetables, but don’t worry about removing peels; these protective layers often contain many of the healthy microbes you’re trying to encourage.

Slow Time

When you’re constantly on the go, the idea of letting something just sit and work it’s magic seems unreal. But that’s exactly what fermentation needs: time. By comparison, you put just a little active time into preparing the produce and brine and packing them into a container. Once you step back, the microbes in the crock or jar mostly need to be left alone.

That said, keep any eye on what they’re up to, particularly when you’re new to fermenting and when during the first few days of the process. You’re watching for brine that creeps below the top layer of produce, vegetables and flavorings that float free of their weight, and foam and a scummy layer on the surface. These can all be part of the fermentation process and are easily resolved when they’re noticed quickly: More brine can be added, weights can be shifted, and foam can be skimmed away. But if they go unnoticed, the air-exposed produce can become discolored or even moldy. So take a peek once a day to make sure everything is nicely tucked below your brine.

Location, Location, Location

Where you choose to let your fermentations sit can be the difference between bright, crisp vegetables and dull, soft ones. Temperature is the most important: room temperature (around 70°F) works well in most cases; above 80°F, microorganisms that soften produce might take hold, and below 60°F, the process may take two or three times as long.

So if your kitchen roasts in the summer, you’ll want find a cooler spot. A clean area in a mudroom, garage, or other space with a concrete floor can keep your ferments cool. If you’re in an overly hot apartment, consider installing a temperature control on a dorm fridge; refrigeration temperatures are too cold to start a fermentation successfully. In many cases, it’s easiest to just enjoy summer produce while it’s fresh and ferment the last harvest of snap beans, cucumbers, tomatoes, cabbage, carrots, and other vegetables.

Light exposure can alter the quality of your fermented produce. Old-fashioned opaque fermentation crocks help keep the produce cool and the light out, but unless you’ve inherited one, they’ve become overpriced collectables. I like to ferment vegetables in quart or half-gallon Mason jars, wrapped in towels and set in a cool mudroom. They’re easy to clean and monitor; simply pull away the towel, and you can see precisely what’s happening in the jar.

Twice as Tasty

All this month, I’ll be sharing recipes that get you hooked on fermenting vegetables. Next week, I’ll introduce you to the process with some vegetables that are barely fermented before they’re transferred to the fridge for storage and can be eaten in a few days. I’ll also share some of my favorite fermented pickle recipes, explaining why they’re superior to even pasteurized vinegar pickles and how to maximize their flavor and crispness, and teach you how to ferment cabbage in German and Asian styles. If you still hesitate to try fermenting vegetables on your own, I’ll be teaching these techniques in workshops through September.

Like what you’ve learned? To learn more in a Twice as Tasty workshop—in your own kitchen, among friends, and with my personal help—click here. If you’re not yet a Twice as Tasty subscriber, get this newsletter and weekly post notifications delivered straight to your inbox by clicking here.