The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Should i store starter in a SEALED jar in the fridge?

gringogigante's picture

Should i store starter in a SEALED jar in the fridge?

I am new to sourdough but have been baking with commercial yeast for years.  This is really different!

I have heard that one must store it where it can breathe or else the jar will explode....doesn't seem plausible to me, but I defer to those that know more than this sourdough newbie!

What say you?

barryvabeach's picture

In most cases, it won't explode, but it can develop a lot of lift .  I use a plastic container ,  with the lid screwed on, so I don't think it needs to breathe.  Note that some recipes, like Forkish,  call for tremendous amounts of starter, and I guess it is possible that it could break a jar.  I normally keep very small amounts ( 15 grams or so ) , in a container that probably hold a half a cup or more,  so there is room for it to increase much more than quadruple in size.

DanAyo's picture

Most often I use glass with a plastic wrap or zip lock bag secured with a rubber band. It is also nice to place a latex glove over the glass so you can watch the glove rise as the container fill with gas. I tell my wife all the time, “I can’t start mixing the dough until the jar gives me the finger”. LOL


HansB's picture

Starter does not need to breath but it does need to exhale. So no tight fitting lid...

OldWoodenSpoon's picture

I've been using those heavy glass snap-lock, flip-top jars with the rubber gasket for years.  When you snap the clasp down the seal "tightly", but pressure can sneak out the seal when necessary.  I have a couple of them that I keep a whole-wheat and also a rye starter in, in the fridge constantly.  I've had my starters in these same jars going on 10+ years.  They sometimes have built up a big "belch" when I open them, but I've never had a spill or anything remotely like an explosion.  The comment above that they need to exhale is right on.  As long as the container allows the relief of the pressure that might build up, it will work.


foodforthought's picture

When I’m waking up my starter to build a levain, I just cover the jar loosely so CO2 can escape. By loosely, I mean I tighten the lid, then back off a few turns. When I’m storing starter in the refrigerator, I tighten the jar lid down snug. No explosions in 25+/- years.



Justanoldguy's picture

I would think that a canning jar, Mason or Ball, should easily withstand any pressure built up by fermentation even with a tight lid. After all they are designed to vent any air in the jar or the vapor generated from its contents by canning, up to 15 pounds per square inch over regular air pressure, otherwise they would not establish the vacuum that seals their lids.

MontBaybaker's picture

How about using one of these, but without the rubber gasket so it's not airtight?  I've used various sizes of these for decades to store whatever; critter-proof and you can see the contents.  You can order replacement gaskets.

HansB's picture

These seem to be the most popular. The straight side make them easy to use and clean. Just remove the gasket and don't use the clips. Just perfect!

Peter_pan's picture

Hello, a few ideas for you:


1. Use a mason jar and instead of a tin can lid, replace the seal part and use a pair of coffee filters. I've used this for making yogurt, kombucha, and other semi-fermentable stuff. I just put the coffee filters under the standard ring. It will be sort of a tight "screw on" process, but they work pretty slick.


2. If you're super concerned about purity, you could buy yourself an airlock used for brewing: 
ou could modify the standard lid for a mason jar with a drill bit to make a hole, then use 100% silicone around the airlock which you would then fix into place. When I was a brewer, I typically filled my airlocks with some sort of hard alcohol (to keep out any "nasties"). This works on a similar principle to your toilet. The water sits in an S shaped tube. In this case, the fermentation will allow CO2 to pass through the air lock, but nothing to come back through. In the case of the toilet, it works the opposite direction, but it keeps the gases below from coming into and stinking up your house.