I love fermented foods, but because I am not very good at exhibiting patience when I am hungry, I rarely make them myself. I cannot fathom having something as delicious as kimchi fermenting in my house for weeks without being allowed to taste it. I would be consumed by my knowledge of its presence, the nearly imperceptible sounds of the fermentation process throbbing inside my brain like a tell-tale heart. There is no shortage of outstanding fermented foods on the market, so I usually see no need to make these products myself.
My one exception: fermented berries. It’s one of those things that literally anyone can make even if they don’t know the first thing about cooking, much less fermentation. It can take as little as 12 hours for the berries to be ready to eat, meaning I can make a jar after dinner one night and be stirring sweet, fizzy berries into my yogurt the next morning. (Or, far more likely, eating them straight out of the jar.) The fermentation process can make your summer berries last for months instead of days, and during those months where quality fresh berries are scarce, you can use frozen ones in this recipe, no problem. Try these at lunch in fancy grilled cheese sandwich, like one made with chevre or brie. Or serve them at dinner, with grilled chicken or in a vinaigrette.
2 cups berries (blackberries, raspberries, and blueberries work best)
1½ tsp. honey, maple syrup, or other liquid sweetener
½ tsp. kosher salt (or ¼ tsp. fine sea salt)
½ cup filtered water, plus extra as needed
3 Tbsp. whey (That liquid that puddles on top of sour cream and yogurt? That’s whey. Use that, then enjoy the sour cream or yogurt later with the berries.)
Wash the berries and gently pack them into a clean jar. Stir the honey, salt, whey, and ½ cup filtered water together and slowly pour it over the berries, occasionally tapping the jar against the counter to release any air bubbles. Add extra filtered water as needed until the berries are fully submerged.
Cut a small circle piece of parchment paper slightly larger than the opening of your jar; lay it directly over the surface of the berries, push down slightly to make sure all the berries are underwater, then place a light weight in the center of the parchment (like a slice of fruit). Seal the jar tightly.
Place the jar into a cold oven with the light on (or any other place whose temperature is consistently, slightly warm) for 12-48 hours. Check on them occasionally, peeking underneath the parchment paper to see if the fermentation process has gotten started. Once you see the liquid begin to fizz, discard the parchment and weight, close up the lid, and store the berries in the fridge for up to two months.