We, the fermenters, know a true thing: vegetable fermentation is quite the simple process. In fact, the only thing you really need to join our ranks is the spirit of discovery and the desire to make food more flavorful and healthful.
There are a couple things that make the process work more smoothly, though. One of those keys to great vegetable fermentation is keeping things submerged. Although vegetable fermentation is possible without full submersion, for the kind of fermentation we’re most usually engaged in, it is better to submerge. Submersion keeps mold and unsightly, distasteful surface yeasts at bay and it make our little probiotic microbe friends oh, so happy.
There are nearly endless ways to keep your vegetables submerged. If you’re fermenting in jars, it pays to be creative. If you’re fermenting in crocks, it’s usually pretty easy to find a weight given that they often come with them and always have wider openings that lend themselves to using plates, bowls and other common kitchen items as weights. I’ve tried a lot of tricks over the years for jar fermentation. Do keep in mind that whatever you use should be food safe and acid tolerant (especially be careful with glass which can contain lead). Here are some that I’ve found to work very well.
Many years ago, I found some cotton, reusable tea bags at a kitchen supply store and had many happy fantasies of all the herbal infusions I would be making with them, and all of the sachets that I would gift to friends with garden herbs. Fast forward to the present day and that hasn’t happened (I do infuse herbs, but I do them fresh or dried in whole sprigs, no bag necessary). I do, however, fill them with ceramic pie weights, which are both food safe and weighty and place them on top of my ferments.
Use these the way you would use pie weights (above). Marbles can be a little trickier, though, since you want to make sure that no lead is in the glass and that there aren’t any glazes that could leech into your food.
A small plastic ziplock bag with a small amount of brine in it. Don’t fill it all the way or it won’t fit in your jar. Place it on top of your vegetables and put the lid on without securing it all the way. The brine acts as a weight (and if there’s a leak in the bag, you won’t dilute your pickling brine). It’s flexible enough that you can still put your lid on. Don’t seal the lid so that the CO2 created during fermentation can easily escape. Downside: there’s plastic on top of your food for the duration of fermentation. This is a cheap and convenient method, but I don’t use it because I have plastic fear.
The enduring favorite in my house. I wrote a post about this lo, those many years ago. Briefly, the idea is to fill a smaller jar with liquid and place it on top of your veggies in a larger jar and cover the whole thing with a cloth. This works best in wide-mouth jars and the cloth napkins I use for the job don’t look so lovely (sometimes there’s overflow, cloths get stained and restained). You could also use coffee filters and paper towel for this job, or be careful about the amount going in so that there’s no overflow.
This falls under the special equipment category, but I have to admit that I love mine. I spotted these lovely, handmade fermentation weights on a fermentation forum a while back and I’ve never regretted buying them. They’re compact, a boon for my urban kitchen, and I continue to find their use simple and neat. If the batch was residue-free, I soak them in a bowl of very hot water before reuse. If there was any leftover stuff on them (surface yeasts or more commonly “foam” bits from the bubbling up of the ferment) I soak them in a distilled white vinegar solution then rinse in very hot water before reusing for the next batch.
Stones are nature’s pickle weights. In Philadelphia, where I live, stones are few and far between and the ones I do find have had congress with too many restaurant-fed cockroaches to ever gain entry into my home. However, some of you are lucky enough to live amongst the non-pigeon birds and dense, unevenly spaced trees, so it might be easy to find a stone of some heft that’s the right size to fit in your jar opening. Stay away from limestone since it is rich in calcite and will react with the acid created during fermentation. Boiling the stone for 15 minutes before using for the first time is a good idea.
Okay, so this isn’t exactly a weight, and it can actually be used in conjunction with a weight, but sometimes, folks, I’m lazy. I peel off a less-than-perfect outer cabbage leaf and shove it down on top of my veggies, place the lid on the jar, being careful not to tighten it all the way and just let the whole thing go.
Fido or LeParfait Jars
Here in the US, Ball jars are very easy to come by and the price is definitely right. There are a couple brands of European jars that seal with a gasket and a clamp. Although, like the cabbage leaf, most recommendations are to use it in conjunction with a weight, you don’t always have to do that, especially with packed ferments. I do use a weight in these jars for brined ferments and for longer ferments (so I can burp them), but I will often do a short kimchi fermentation (3-7 days) in a Fido with no weight at all. The gasket allows excess pressure to escape and the build-up of CO2 from the fermentation process provides a protective layer that keeps oxygen from the surface during fermentation. I straight-up had a fido explode on me (annoying because of the clean up, dangerous because of the flying glass (no one was awake or hurt so it was okay) and frustrating because it was a gallon jar that cost more than a case of any of my other jars), so this is definitely something to approach with caution, and is best for more experienced fermenters.
You don’t want to “burp” these jars regularly if you’re not using a weight. That will take the protective CO2 layer out and leave you with the potential for surface yeasts or molds. If you are using a weight, burping regularly is fine, since the liquid layer at the top is providing the barrier to air.
A Fork a Day
This could also be known as the do-nothing weight, although it’s actually a bit more labor intensive than any of the solutions you see above. In the case of a packed pickle (sauerkraut or kimchi style pickles) this is sometimes a reasonable method. What do do? Nothing, really. Just put the jar on a shelf, packed as tightly as possible, lid lightly attached. Every day, open up the jar. Scrape down the sides and press everything back down with a fork until there is a liquid layer once again.
How Do You Keep Your Ferments Submerged?
I’ve used all of these methods at various times for various reasons. They all work fine, but I definitely have my favorites. And this list is certainly not comprehensive, so tell me: how do you keep your veggies submerged?