We get this question from time to time (or one like it:
What jar should I use for fermenting?
There are endless options: ceramic crocks, mason jars, bowls, plastic (not uncommon in brewing and winemaking) and many others.
My answer comes with 2 caveats:
- The question is somewhat flawed; more information is needed. Are you fermenting a gallon of cider, a 6.5 gallon carboy of wine, a few cups of carrots or something else? The volume – and the ingredient – play key roles.
- There is massive differences in personal opinion and many of them are cultural. For example, mead (honey wine) is often fermented without oxygen using an airlock while T’ej (an Ethiopian Honey Wine) is often fermented in open air. And, of course there are exceptions too. This means, almost certainly, that any advice I share is bound to be met by a protest that my advice is wrong (which, to some, it will be).
My first thought is that, generally, there are few wrong choices. Start with something clean, non-reactive and lead-free (some old ceramic crocs are not) and you’ll do just fine.
The problem with this advice is that it’s incomplete – ‘fine’ is a relative word. You could technically ferment grapes on a non-reactive cookie sheet (i.e. a thin layer of juice spread over a wide area and lots of air) and it would ferment. With the significant amount of oxygen involved, it’s likely that you would end up making vinegar which would be fine if that’s what you wanted – but it you were aiming for booze then you might want to choose something that will allow you to remove the oxygen (like a carboy, gallon jug or fermenting bucket).
And while there are exceptions, a general rule for making booze is using something with a thin neck (like a gallon jug or carboy) or a container that you can attach an airlock to (including fermenting buckets or mason jars with airlock attachments).
If you’re fermenting vegetables, I ask myself a few questions to help guide my decision of choosing the ‘right’ jar:
- How much am I fermenting? Will it fit in the vessel I wish to use?
- Where am I storing this when done? If it’s in the fridge, will this jar fit?
- Does the ferment need to be weighed down (common with things like cucumbers that you want to stop from floating above the surface of the water)? If so I need to choose a container that will allow for something to hold the vegetables down (this includes using a 1/2 cup mason jar inside a wide-mouth mason jar or plates in a large ceramic croc).
- Do I want to keep the air out? If so, this eliminates bowls and many wide-mouth jars and means I’ll use a mason jar with a regular opening (like this) or for larger batches I’d use a croc with a water channel that acts as an air lock (like this).
- What do I have on hand? I’ve used cookie jars, mason jars, open bowls, crocs and more. It rarely requires specialized equipment so I look around the house.
For those of you who are experienced fermenters, how would you answer this question? We’d love to hear your take on this answer woo.. 🙂