Things that WILL kill your sourdough starter
It's best to maintain your starter at comfortable room temperature (around 70°F), though a little higher or lower won't hurt anything. SEVERE NEGLECT: If you neglect your starter long enough, it will develop mold or signs of being overtaken by bad bacteria.
The best way to tell if your sourdough starter is dead is if it does not respond to regular feedings. When you add fresh flour and water to the mix, you should see it come back to life through bubbling.
To revive your old sourdough starter (or make starter more active), try feeding it with half regular flour (bread flour or all-purpose) and half wheat or rye flour. Rye seems to make sourdough starter especially bubbly! Your starter may be cold. Use a thermometer to monitor the temperature where the starter is stored.
A mature sourdough starter can last for several weeks to months if kept in a refrigerator without being fed.
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.
What if I miss feeding my sourdough starter? If you miss one of your starter feedings, it'll be just fine.
A starter stored in the fridge can be fed once a week. If you plan to use it often, you can store it for up to two months without feeding. When you want to use the starter again, remove it from the fridge for a few hours, then feed it every 12 hours for 36 hours before you make bread with it. Need a really long break?
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.
Allow the starter to rest at room temperature (about 70°F) for at least 2 hours; this gives the yeast a chance to warm up and get feeding. After about 2 hours, replace the starter in its storage container and refrigerate.
Some other signs your sourdough starter is being overfed are: sourdough starter not bubbling or rising. not smelling yeasty. starter is runny.
A sourdough starter is dead when it doesn't respond to regular feedings. If this is the case, the starter needs regular refreshments to be brought back to life. You may also see mould or discolouration, if this happens it's often best to throw it out and start again.
Yes, you can overfeed your sourdough starter. Audrey explains: “Every time you add more flour and water, you are depleting the existing population of natural bacteria and yeast.” If you keep adding more and more, eventually you'll dilute the starter so much that you'll just have flour and water.
With an aggressive feeding schedule (2-3 times daily), you should begin to see bubbling and sour notes by day three (and is a good indicator for collecting the Lactobacillus bacteria). By Day 5, I typically give up if there's no rise or sour notes. There's two common factors that make sourdough fermentation difficult.
How to increase a starter. If your recipe calls for more than 227g (about 1 cup) of starter, feed it without discarding until you've reached the amount you need (plus 113g to keep and feed again).
The oldest known sourdough starter is said to have originated from clay pots unearthed in Egypt. Seamus Blackley baked a loaf of sourdough bread using yeast harvested from 4500 year old clay pots. If you want to read more about this 4500 year old sourdough starter, go here.
If you don't feed it often enough, the sourdough starter starts to smell like alcohol. You may also find that the starter loses its vibrancy and doesn't get too bubbly and active after a feeding. Don't worry, you can always get the starter to recover.
You most definitely can bulk ferment sourdough too long. If you leave the dough to ferment for too long, it will become "over fermented". Over fermented dough will lose its structure and become a soupy, sloppy mess that you will not be able to shape.
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.
A mature sourdough starter will reach its peak around 2 to 4 hours after being fed. If it's particularly cold, or you've given it a huge feeding ratio, this could be extended to 12 hours.
I do NOT recommend storing your sourdough starter or discard in a jar with an airtight lid that clamps closed unless you're using your starter more than once a week. Those need to be "burped" (opened) regularly to let gas out. Sourdough starter can be stored at room temperature or in the fridge.
When maintained at room temperature, the sourdough starter should be fed every 12 to 24 hours, depending on the specific starter and culturing conditions.
Choose a clear, straight-sided jar without shoulders for easy cleaning and feeding. Ideally, a wide mouth glass canning jar with a 16 - 32 oz capacity, but a food-safe plastic deli or food storage container will work too. Look for something with a lid that can be placed on without securing the container airtight.