Sourdough starters do not in fact breathe and therefore do not need to have access to fresh air. However, the organisms in your sourdough starter do emit carbon dioxide, which is a gas that can build up inside the jar.
It will need a lid or cover, but not something airtight: Sourdough starter emits gas, and a sealed canister can explode. If you have intermittent baking plans, you may want something that can be lidded more tightly and stashed in the refrigerator.
Oxygen: Fermenting sourdough starters will produce carbon dioxide. The starter should be loosely covered in order to safely release the gas, but the culture does not require oxygen.
Storing your sourdough starter in the fridge will require feeding around once a week. It can, however, be stored up to two months in the fridge without being fed. Reviving a sourdough starter that has been stored in the fridge for a longer period of time is a good idea.
The best way to store a sourdough starter in the fridge is to place it in a glass or plastic container covered with a lid. The lid should not be air-tight as it needs a little air but we do not want pests getting into the starter.
Sourdough starter can be stored at room temperature or in the fridge. If you're feeding and making bread with your starter regularly (once a week or so) you can leave it out at room temperature. If you're going away for a bit or if you don't use it that often (once a month or less), store it in the fridge.
To keep it in the fridge, feed it at least one a fortnight (always discarding before you feed). You don't need to leave it out, you can feed it and put it straight back in the fridge if you aren't going to bake with it.
Storing your sourdough starter
If you aren't intending to use your sourdough starter every day, it is best kept in the fridge. To do this, feed it as instructed above, seal the jar and then stand at room temperature for 2-3 hours (to help reinvigorate the yeast) before placing in the fridge to store.
The very short answer is, your sourdough starter generally will be at its peak anything between 4 and 12 hours after feeding. The optimum time to use it will be when there are lots of bubbles at its surface and it has has physically risen to its peak level, just before deflating back down again.
You can either discard this liquid (or “hooch,” as it's commonly called) or stir it back into the culture. I typically stir it all in together. This can be a sign you're not feeding your starter often enough.
Yes you can use sourdough discard straight from the fridge, you don't need to let it come to room temperature if you don't want to. What is this? If you are using it straight from the fridge it may be a little stiff or thick, so you'll need to ensure you mix it really well.
To ready your refrigerated starter for baking: Take the starter out of the fridge, discard (or set aside) all but 1/2 cup (113g) and feed that 113g as usual with equal parts (113g each) flour and water. Cover the starter and let it rest at room temperature.
You can leave the starter in the refrigerator for 3 to 4 days at a time between feedings. We recommend feeding sourdough starter at least twice a week for best results. Remember, if you're planning to make bread on a given day, you'll feed sourdough starter the night before you bake.
People often worry if they've killed their starter by leaving it in the refrigerator for a long time without feeding it. When it's refrigerated, the yeast slows down and becomes practically dormant. A yellowish liquid usually forms on top, referred to as "hooch" by sourdough folks.
Do I have to feed my sourdough starter twice a day? No. You can scale back to once a day or even scale up to three times a day, whatever works for you and your schedule. I like to feed it at least once a day to keep it strong and ready for baking.
Room-temperature starter should be fed every 12 hours (twice a day) using the standard maintenance feeding procedure: discard all but 113g, and feed that 113g starter with 113g each water and flour.
What if I miss feeding my sourdough starter? If you miss one of your starter feedings, it'll be just fine. Give it a feeding when you next remember it needs one, and continue with your daily feedings as usual.
A mature sourdough starter can last for several weeks to months if kept in a refrigerator without being fed. If your sourdough starter has been in the fridge for a while and you want to give it a refresh, follow the steps below. Discard all but 25 grams and add 100 grams of filtered water and 100 grams of flour.
While mold on a sourdough starter is fairly rare, it does happen from time to time. You can check our sourdough starter for sale to start making sourdough bread. The cause is usually some sort of contamination with food or soap residue or weakened yeast due to a forgotten feeding.
The rule of any kitchen is “When in doubt, throw it out,” but I wouldn't panic and toss your starter if you only missed 1-3 days of feeding. If it's more than 3 days AND you have a warm kitchen, you'll have to make the call based on how well you know your starter.
Myth 7: You can't overfeed sourdough starter.
While starters do need regular feeding, it is possible to overfeed one. Each time you feed a starter, you thin out the population of microorganisms by adding flour and water.
If your bread had a good rise and is still holding gas but got sticky while shaping, then it may be overworked. All bread dough requires a very gentle touch at this stage. If you break the gluten strands at the shaping stage by overworking the dough it will get sticky, flatten out in a blob, and won't look smooth.
The overall process typically takes 7 days, if the temperature is warm enough. However, it can take up to 2 weeks or more for a strong starter to become established.
METAL: Stirring your starter with a metal spoon or placing it in a metal bowl won't kill your starter. While we don't recommend making or keeping your starter in contact with reactive metals like copper or aluminum, stainless steel is harmless.
As part of the feeding process, most bakers discard some of their sourdough starter before adding fresh flour and water to the jar. This is done to refresh the acidity levels (think sweet vs. sour smell) and to manage its overall growth in size. This technique is crucial for successful sourdough bread.