The absolute easiest veggie preservation trick
It sounds intimidating, but fermenting those fall veggies is super simple
Hiya squash blossoms, and welcome back to Cool Beans! We’re in the heart of harvest season, when many fruits and veggies are bountiful and at their best. Pretty soon there will be a lot less variety, which got us thinking about how to capture fall produce at its peak. So we’re diving into the Technique Toolbox with James Beard Award–winning editor and cookbook author Darra Goldstein to talk about the age-old food-preservation method of fermentation, which turns ephemeral flora into pucker-inducing, long-lasting goodies like sauerkraut and kimchi.
To showcase the method, she pointed us to a recipe for fermented winter squash in her new book, Preserved: Vegetables, the fourth in a series of volumes she co-authors with chef Cortney Burns and longtime food and lifestyle editor Richard Martin. While the process is dead simple, Goldstein admits that it can feel uncomfortable for beginners, because over the days and weeks it takes for food to ferment you need to trust that it isn’t spoiling—even if you start to see a few spores. Most commonly, that will be a harmless white layer of yeast or a little surface mold. “I know that for some people, initially myself included, the idea of fermenting something maybe seems daunting or scary,” Goldstein says. “But if you see some mold, you just scrape it off. I’m pretty badass about it now.”
The technique
In terms of process, there’s not a ton to do—except wait and trust. Peeled veggies get stuffed into a sterilized container, then covered in a salty brine. The key to staving off bacterial bad guys is keeping the veg submerged, usually by weighing it down with a small saucer or other kind of weight. Seal the jar tightly, and that’s pretty much it.
The contents do need to “burp” every few days, which means opening the jar to let out the CO2 that’s built up, or choosing a container whose lid has an airlock that’ll release the pressure on its own. (If you don’t know what that last part means, yours probably doesn’t.) While you’re at it, you can also check for mold and scoop any off; if it’s so much that it’s making you nervous, you can always scrap that batch and start again. In a few weeks, the veggies are ready to use.
Why it works
Fully submerging veggies in brine creates an environment that’s inhospitable to unwelcome microbial growth. In the right concentration, “salt allows the good bacteria to thrive while killing the bad bacteria,” Goldstein says. In this case, the good guys are lactobacillus—hence the name lacto-fermentation.
Those good microbes go to work on the veg, turning its naturally occurring sugars (including lactose) into lactic acid. This process creates a perfect high-acid, low-pH habitat for the veg, a balance that keeps it from spoiling, maintains, and, in some cases, even enhances its nutritional value and injects it with scrumptious sourness and gut-friendly probiotic properties.
Variations and uses
This process will work with almost any veggie, but the proportion of salt to water, and the time it takes for vegetables to ferment, will vary depending on their texture and density—and your desired level of sourness. Squash will take about three weeks to get to the promised land, while cabbage and cucumbers require less time, and carrots and beets might need more.
You can play around, but not with the salt, Goldstein warns. Avoid the iodine-fortified kind, because it can inhibit bacterial growth. The recipes in Preserved call for Diamond Crystal kosher salt specifically. You can use Morton or another option, but it’s best to check the measurements online, as volumes can vary among brands.
How you use the final result also depends on the veggie in question. Winter squash, Goldstein says, “feels hard when you first cut into it, but it’s actually a soft flesh so it breaks down in a way that other vegetables don’t.” For this reason, it’s not suited for snacking the way other pickled produce can be. Instead, it’s ideal for soups and stews, or whipped up into a purée you can use as a dip, spread, or side.