Sourdough is a time-honored method of breadmaking that relies on wild yeasts and bacteria naturally found in flour and the environment. Instead of using commercial yeast, sourdough ferments over time, creating a bubbly, living starter that’s used to rise and flavor the dough.

The result? A loaf with a tangy, complex flavor and a chewy crust that sets it apart from regular yeast-leavened breads. That sour bite comes from lactic acid, a natural byproduct of fermentation, which also gives sourdough its impressive shelf life and digestibility.

Sourdough cultures thrive in warmth, with their sweet spot landing between 70–78°F. If it dips below 70°F, expect things to slow down quite a bit. But if temps climb above 85°F, you risk damaging—or even killing—your culture.

That liquid is called hooch, and it’s completely normal. It’s a sign your starter is hungry and hasn’t been fed in a while. Hooch is essentially alcohol produced by the wild yeast during fermentation, and it can range in color from clear to gray or even dark brown depending on how long it’s been sitting.

If you prefer a milder, cleaner flavor in your bread, go ahead and pour the hooch off before feeding your starter. But if you’re after that signature tangy sourdough punch, feel free to stir it back in—just know it might make things a bit more acidic.

Either way, it’s your starter’s way of telling you it’s time for a snack. Keeping to a regular feeding schedule will help prevent hooch buildup and keep your culture healthy and happy.

To avoid any risk of cross-contamination, it’s best to keep your sourdough starter at least 4–5 feet away from other active ferments like yogurt, kefir, kombucha, or anything else that’s bubbling away on your counter. These cultures can release yeasts and bacteria into the air, and while they’re all friendly in their own way, they don’t always play nice together.

If you need to store multiple ferments in close quarters—like in the fridge—make sure each one is sealed tightly with an airtight lid. This helps prevent mingling of aromas, flavors, and most importantly, microbes. A little distance goes a long way in keeping your cultures pure and thriving.

If your starter stinks, don’t panic—it might not be doomed! A bad smell is usually your starter’s way of crying out for help. Let’s break down what your nose might be telling you:

• Nail polish remover or acetone smell? That’s a classic sign of hunger. Your starter is running low on food (sugars) and producing excess alcohol as a result. A good feeding should perk it right up.

• Rotten eggs, sulfur, or fart-like smells? That’s more concerning. It likely means your starter is seriously starving or potentially contaminated. It’s not a lost cause yet, but you’ll need to feed it consistently for a few cycles—sometimes two or three times a day—to see if it can bounce back.

Give it about 2–3 consecutive feedings and watch for improvements in smell, texture, and bubbles. If it still smells foul after that, it may be too far gone or not worth the effort. In that case, it’s best to start fresh with a new culture.

For reference, a healthy starter should smell pleasantly yeasty, mildly tangy, and maybe a little fruity or bread-like—not like something that crawled out of a compost pile. Trust your nose—it’s your best tool when it comes to sourdough survival.

There are a few solid signs that your starter is strong, active, and ready to leaven. Most obviously, it should double or even triple in volume within 4–6 hours of feeding, especially if it’s kept nice and cozy around 75°F. Look for a fluffy, bubbly texture and that classic tangy, slightly sweet aroma—your starter should smell alive.

And while we’re here, let’s bust a few myths:

• The float test? A charming tradition, but ultimately a myth. It’s inconsistent and depends on too many variables—hydration, flour type, temperature, even how you scoop it. Don’t put too much stock in whether your starter swims.

• Hungry starter? Totally fine to bake with. In fact, many seasoned bakers prefer the flavor and flexibility of using a slightly hungry starter. The idea that you have to use it at its “peak” is another myth—fermentation isn’t that fussy.

• Discard? Once your starter is activated and thriving, there’s no such thing as discard unless you’re just managing volume. It’s all usable.

Looking for a zero-waste approach? Try the scrapings method. Instead of maintaining a large starter and tossing excess, you feed just a tiny amount—literally the dried scrapings left in the jar after using your starter. This low-maintenance method is perfect for minimalists and small-batch bakers. When you’re ready to bake again, just build it back up with fresh flour and water. No waste, no guilt, no discard.

Bottom line: a healthy starter is flexible. Forget the rigid rules and listen to your culture—it’ll let you know when it’s ready.

You should be feeding your starter daily. Schedules can be anywhere from every 24 hours to every 8-12 hours depending on how often you decide to bake bread. If you cannot feed your starter daily, you can feed the culture with the 1:1:1 ratio, let sit for an hour on the counter or top of your fridge, and then place in the fridge. By doing this, you can stretch your feeding to once weekly and when you decide its time to bake, then simply take out desired amount of starter and weigh it. Feed it its weight in equal parts water and flour. For example: 100 grams of starter will need to be fed 100 grams of water and 100 grams of flour. Let ferment for 5-8 hours and use in recipe.

Sourdough cultures are very resilient and can take quite a bit of neglect. If the culture hasn’t been fed in quite a while there will likely be pooled hooch floating on the top. Just pour it off and let the starter sit on the counter until it comes to room temperature. Feed it every 8-12 hours until you see signs of fermentation (doubles in size or air bubbles). If there aren’t any signs of life the starter, may need to be replaced with a new culture.

Excessive heat is fatal to sourdough cultures. The only way to know if your culture is alive is to continue to feed it. If there are signs of activity or air bubbles, bullet dodged! If there are no signs of fermentation after a few consecutive feedings, the culture is most likely dead and you will need to start over with a new culture.

To avoid this potential disaster next time, tie a red or other bright colored scarf or dish towel to the oven handle to signify precious cargo inside. Some of us will tape a note on the knob that turns the oven on, because we’ve noticed that occasionally, people just don’t notice the proverbial tie on the door knob. 

Lastly, make sure your oven doesn’t go above 85 with the light on. If you don’t have a thermometer to check, don’t risk it.

It can become overwhelming quickly if you are religiously feeding your sourdough cultures but not actually using it. One can only make so much bread. How much bread? Not sure yet because neighbors and friends haven’t started complaining. We’ll let you know when we find out, though. Thankfully, sourdough’s uses are not limited to baking bread. Its uses are endless! From sourdough pancakes, waffles, crepes, tortillas, muffins, cakes, donuts, bagels, pretzels, English muffins, and a whole lot more. You can even brew beer with it - just use starter when you pitch your yeast instead of whatever packet (and don’t forget to save the leavings for a loaf of bread later: you’ll be shocked by its rise!)! Check out our blog for upcoming sourdough starter recipes.

Under normal circumstances, a healthy sourdough culture being either partially or fully frozen shouldn’t harm your sourdough culture. However if it's been awhile since it’s been fed or has been neglected it may take some effort to revive it. First you will need to defrost it. Once defrosted, feed it back to back every 8 hours until bubbly. It is possible that uh… a single member of our team has forgotten a sourdough in the frozen part of the fridge for months a time or two and still managed to revive it. We’re not saying this has really happened, but it might have. If the culture doesn’t bubble after a few feedings, it’s likely that you’ll need to scrap it and start over with a new culture. But we’d say give it a few days to make sure, and make sure to discard half of the reviving culture before each feeding to give it a better chance at renewed vigor. You can stick that discard in brownie batter, if you like

The difference between sourdough starter varieties basically boils down to location, bacteria, and yeasts. For example, San Francisco sourdough starter contains Lactobacillus sanfranciscensis, which is a bacteria unique to San Francisco. Different bacteria and yeast give each variety a distinct taste and level of sourness.

To convert a commercial yeast recipe to sourdough, standard formula for volume is 1 cup active 100% hydration starter = 1 packet of yeast + 3/4 cup flour + 1/2 cup water

For weights, subtract half of the weight of the starter you’re going to use from each the fluid and flour of your recipe, and ignore the yeast it asks you to add.

Gluten free starter does not respond well to long term storage. If you do decide to store it long term, just know that it will need some extra TLC and patience.