Sourdough starter in a cold kitchen: a winter routine

Winter slows a starter down. King Arthur Baking's Martin Philip says his kitchen can swing as much as 20°F (about 11°C) between summer and winter, and that 60°F (16°C) in January is too cold for his starter to thrive. You don't need to heat the house. You need a warm spot, a few feeding tweaks and a thermometer.

If your starter has already stopped rising and you're not sure why, start with why is my sourdough starter not rising? This post is the everyday winter routine.

What temperature a starter likes

King Arthur says the best environment is about 72°F to 78°F (22°C to 26°C). University of Illinois Extension says 70–82°F (21–28°C) works best, with the warmer end giving a more active starter. Colorado State University Extension's rule of thumb: temperatures that feel comfortable to you, around 70°F (21°C).

Below that, everything slows down. King Arthur says the colder the environment, the more slowly a starter grows, and below 68°F (20°C) fermentation can take much longer. At 75°F (24°C) or above, a healthy starter should double within 6 to 8 hours of a feeding.

Find a warm spot

If your kitchen sits below 68°F (20°C), King Arthur suggests finding a smaller, warmer spot. Ideas from their guides:

• On top of the fridge or water heater, or another appliance that gives off heat. The top of an appliance that runs all the time is usually a bit warmer than the room.
• Near a radiator, vent or baseboard heater. King Arthur notes the heat can cycle on and off, so it's less steady.
• In a turned-off oven with just the light on.
• On a heating pad at its lowest setting, with a folded dish towel under the container, or on a heated mat.
• In a temperature-controlled proofer. King Arthur calls one the ideal solution, worth considering if you bake a lot.

Two cautions. First, King Arthur says to check the starter's temperature now and then so it isn't getting too hot. Colorado State says fermentation can run too fast or even stop when it's too hot for your own comfort, and Illinois says a starter kept too warm eats its food so fast that it peaks and falls too quickly.

Second, remember a starter in the oven. King Arthur warns that if you forget it's there and turn the oven on, it's unlikely to survive. Yeast dies at 140°F (60°C).

Adjust the feeding for the cold

Use warmer water. King Arthur says to feed with lukewarm water when your house is chilly, and suggests warm water, 80–90°F (27–32°C), instead of cool.

Keep the ratio at 1:1:1. That's equal weights of starter, flour and water. King Arthur and Illinois both say the more flour and water you add relative to the starter, the slower it rises. A starter in the cold is slow enough already, and 1:1:1 is the minimum King Arthur recommends anyway.

Add some whole grain flour. King Arthur says rye, whole wheat or pumpernickel at 10% to 20% by weight of the white flour gives the microbes more nutrients and speeds up fermentation. In a 50 g feeding, that's roughly 5 to 10 g. Illinois suggests switching a sluggish starter to rye.

Expect the timing to stretch. King Arthur says the warmer your kitchen, the faster your starter rises and the sooner it needs feeding, so in winter the peak comes later. At about 78°F (26°C), they say a 1:1:1 feeding usually peaks in 4 to 6 hours, but it varies with the starter and the kitchen. Watch the starter, not the clock. A rubber band around the jar at the starting level, as Clemson Extension suggests, makes the rise easy to see. For schedules, see how often to feed a sourdough starter.

Fridge starters, too. After a weekly feeding, King Arthur says to leave the starter out for 1 to 2 hours before it goes back in the fridge, and the longer time if your kitchen is cool. More in storing a starter in the fridge.

A cool kitchen isn't all bad

Slower can be handy. In a King Arthur post, baker Andrew Janjigian says he holds his starter at a steady 65°F (18°C) and feeds it once a day instead of twice, and it stays happy and active. He uses a temperature-controlled box to keep it there. If your kitchen is cool but steady, learn how long your starter takes to peak there and plan around it.

Use a thermometer

Illinois calls an indoor thermometer optional but says knowing the room temperature is helpful. Warm spots vary a lot. In one King Arthur post, an oven with only the light on reached about 76°F (24°C) after an hour on a winter day. In another, an electric oven held 85–90°F (29–32°C) that way, above the ideal range. Check a new spot before you trust it, and note the temperature when you feed so you can see how your kitchen affects the timing.

Slow or stalled?

In the cold, slow is normal. King Arthur says the cooler the room, the longer a starter takes to work. It may also have risen and fallen while you weren't looking: King Arthur says fresh residue on the side of the jar shows it doubled.

To tell slow from stalled, give it a fair test. Feed it and put it somewhere 75°F (24°C) or warmer, where King Arthur says a healthy starter should double within 6 to 8 hours. If it does, the cold was the problem. If it doesn't, work through the not-rising checklist, which covers the other causes, from a young starter to a thin mix.

Don't give up on it because of the cold. King Arthur says a mature starter is very hard to kill, and that fridge cold slows fermentation to a crawl, which is why a fridge starter survives on weekly feedings. If yours has been neglected for a long time, or shows mold or a pink or orange streak, see is my sourdough starter dead?

A winter routine, in short

• Find a spot around 72–78°F (22–26°C), and check it with a thermometer.
• Feed 1:1:1 with lukewarm water, and add a little whole grain flour if it's sluggish.
• Mark the jar and judge by the rise, not the clock.
• If it won't rise even in a warm spot, work through the not-rising checklist.

How Sourdough Starter Tracker helps

The feeding log has an optional Room Conditions section, where you can record the room temperature (and humidity) with each feeding, so over a winter you can see how your kitchen affects your starter. Each starter has a status, Active, Refrigerated or Dormant, and reminders follow it: Active reminds you 1 to 3 times a day at times you choose, Refrigerated every 7, 14 or 21 days, and Dormant not at all. If your starter stalls, the Troubleshooting screen's "My starter isn't rising at all" item suggests a spot at 75–80°F (24–27°C) and whole wheat flour. Each starter's face shows when it's getting hungry. Premium, a one-time purchase, adds Smart Health Tips, a personalized analysis of your temperature, feeding ratio and more.

Sources

• King Arthur Baking: Winter is here. Make these 5 changes to your bread baking, Why is my sourdough starter not rising?, Your starter is missing one crucial ingredient: temperature, Sourdough starter recipe, Creating a starter, How to make sourdough starter, Where to put bread dough to rise, Putting your sourdough starter on hold, Sourdough starter troubleshooting, Sourdough feeding ratios, Feeding and maintaining your starter, Sourdough starter feeding schedule (2026), Sourdough Tips and Recipes (2026)
• University of Illinois Extension: Sourdough 101, Sourdough webinar FAQ
• Colorado State University Extension: Sourdough starter best practices
• Clemson Extension: How to make, feed and bake with a sourdough starter