I made dill pickles recently, using the recipe my grandfather taught me when I was about 8. He was from Poland, born in 1907, and grew up very poor. Preserving food for the winter was not a hipster hobby—it was a matter of survival. This is how a lot of fermentation traditions around the world came to be, especially in areas with harsh winters. That these myriad methods for preserving food—from pickles to vinegars to garums to charcuterie and beyond—taste much better than the raw materials is one of the defining miracles of food here on planet Earth.
My grandfather’s method was super simple: cucumbers, a few garlic cloves, and a big bunch of dill in a jar covered with 5% brine (50g salt per liter of water). He boiled rocks and used those as weights to hold the cukes below the brine, and then put the jars on shelves in his basement and let them ferment. That’s the whole recipe. These days, I don’t use 5% salt for lacto ferments (though I do use that percentage for a lot of koji things, like shio koji).
His pickles taught me the three things you need to know to pull off lacto-fermented pickles:
Brine. 2% is the minimum safe percentage, but if you’re pickling whole vegetables like cucumbers the salt will pull water out of them, diluting your brine. So For a pickles like this I’d recommend using at least 3%, even 4% to be safe—especially if you’re packing the veg tightly so there isn’t a lot of empty space for the brine to occupy.
Weight. Lacto pickles need to be held beneath the liquid while they ferment. Anything that sticks up above the surface will grow mold.
Temperature. If you have a basement, you’re in business. If not, find a cool spot that’s ideally between 55˚-65˚F. If you don’t have that, leave your jar out on the counter for a day or two and then move it to the fridge. It’ll ferment much more slowly in there, but it will happen.
If you’re currently covered in cucumbers like those of us who garden in these latitudes, go forth and make pickles. But this post is actually about what I did after the cucumber pickles got eaten and given to friends. I had this big jar of delicious, garlicky-dilly brine and couldn’t bear the thought of pouring it all down the drain. Coincidentally, I had been trellising my tomatoes and some branches got cut (both purposefully and accidentally) in the process. So I had a decent supply of green tomatoes on hand. You’ll won’t believe what happened next!
First, like I said above you need to be aware that your vegetables will dilute your brine. The cucumbers had done this, so I added another 2% salt to that brine before adding the tomatoes (I left the garlic and dill in the jar because why not?) I also sliced a serrano pepper and added it to the jar to give the tomatoes a little heat and simpatico flavor from their nightshade cousin.
Then I let them sit for about a week. They’re just swell now—tart, hot, salty, and addictive: everything you look for in a pickle. I like to slice them into wedges and serve them as part of an appetizer spread, or chop them finely and add them to everything from tuna salad to tartar sauce. You can also slice, flour/egg wash/seasoned cornmeal them, and make amazing fried green tomato pickles.
There are other uses for brine that I can go into later on, but for now when you finish a jar of pickles think about what might also enjoy a fortifying bath in the magic liquid that remains. Just remember to bump up the salt, and consider what secondary flavors (like the serrano) you might want to add. This won’t necessarily work forever, but depending on the vegetables you’re fermenting and the flavors you layer, you might be able to get another jar or three out of your brine.
The bacterial populations in a jar do vary over the course of a fermentation, so the microbes present at the end will be different from the ones that got the ferment going. So some flavors can be slightly different. But it’s worth reusing your brine once or twice for sure. After that, have you tried making gravy with it? Freaking fabulous. Report back!