And then you hope that it goes bad in a good way. Just like when you're growing a sourdough starter or making yogurt or creme fraiche, you want the good bacteria to ward off the bad.
My mother made fermented pickles in an old pottery cookie jar. More than half the time, the pickles went bad. And once they started to go off, there was no saving them. The pickles would get soft and slimy, and they'd start to smell bad. And then she'd toss them and try another batch.
Kraut Kaps ($9.99) are designed to help prevent the bad bacteria from working their evilness on the pickles, while letting the good bacteria proliferate. It's a simple idea, really - an airlock on the top of a cap that fits a wide-mouth canning jar.
So ... does it work? I made two batches of fermented pickles, and both were successful. Now, I have a batch of sauerkraut in process. It's bubbling like it's supposed to after a couple weeks, and I'm not seeing any sign of terrible things happening.
Whether these products would have worked without the airlock is the question. I've successfully made pickles and sauerkraut without a gadget, but it requires a lot of attention, scraping off the scum on the top, adding water as it evaporated, and constantly looking for mold or whatever. this was a lot easier.
I still checked the pickles on occasion, and there was a little evaporation, but I didn't need to check every day. And that made the process a lot easier.
And for those with sensitive noses, not much aroma escapes the jars.
Even with these caps, you can still introduce bacteria into the process with a jar that isn't quite clean enough, or pickles that aren't washed well, or utensils or other ingredients that could introduce bugs. But the caps do keep nasties from coming in from the outside. So your chances are better.
The caps were recently redesigned with silicone replacing parts that were previously made from rubber, so these new ones should last a bit longer.
The lids are a bit pricey, but if you do a lot of pickling, they could save you from having to throw out batches of pickles that have gone bad. Also, since the lids fit wide-mouth canning jars, you're limited to the batch sizes you can make - I used half-gallon jars. I'm not sure if larger ones are available.
If you've never made old fashioned fermented pickles, you can find recipes at the manufacturer's website: http://primalkitchenproducts.blogspot.com. They're also setting up a new site at http://www.primalkitchencompany.com, so check there for updated information.
The product was supplied for the purpose of a review on Serious Eats; this was previously published on Serious Eats.