Temperature is everything when it comes to sourdough starters. It can make the difference between a starter that rises and one that stays flat. The temperature of the starter also greatly influences the taste and the texture of the bread. So, it’s very important to get it right, and maintain it that way.
Some of the best ways to keep your sourdough starter warm are:
- Keeping It in the Oven With Light On
- Placing It on a Seed Raising Mat
- Keeping It Next to the Oven
- Covering It With a Tea Cosy
- Keeping It in a High Place
- Placing It in a Proofing Box
- Using a Kombucha Jar Band
- Using a Heating Lamp
But, those are not the only methods that you can use to keep your starter warm. In total, I will cover 23 different methods that you can use to keep your sourdough starter warm. But before we go over them, I want to remind you that too much heat can be even worse than too little. So you don’t want your starter to be too warm, either.
Finding the Ideal Temperature for Your Sourdough Starter
The overall best temperature to keep your sourdough starter at is between 75°F to 82F°(24°C to 28°C).
But if you go a little higher or a little lower, nothing bad will happen, in fact depending on how you like your sourdough, something good might come out of it.
A sourdough starter is basically wild yeast, and yeast is made out of tiny little good bacteria (also known as probiotics) that eat the sugar and starch in the flour and make it grow. Yeast can survive at temperatures as high as 100°F(49°C) and as low as 34°F(1°C). But at those temperatures, the way they work is a little different.
At higher temperatures, the yeast become more active, which means that it will eat the flour faster, which means that you have to feed it more often, sometimes up to 2 or 3 times per day, if you don’t the starter will develop hooch. (you can find out more about hooch in this article: Sourdough Starter Hooch – What It Is and What to Do With It). And the bread that you will make with this starter will be less sour, and it will rise faster.
At lower temperatures, the yeast becomes less active, so it will need to eat less, once every two or 3 days, and if you keep it in the fridge, you will need to feed it as often as once per week. A starter that is kept at lower temperature will make your bread taste even sourer. But the dough will need more time to rise, and the bread might not be as airy. This is why it’s recommended to warm up your starter 2 or 3 days before using it.
So, there is no ideal temperature for a starter, but a good middle ground is 75°F to 82F°(24°C to 28°C). If you want to know more about how the starter works, you can check out this article: Does Sourdough Contain Probiotics? (+ What They Do).
And if the idea of a less sour sourdough bread appeals to you, check out his article: 21 Ways to Make Sourdough Bread Less Sour Tasting. Or if you like a really sour tasting sourdough, check out this one: 21 Ways to Make Sourdough Bread as Sour as Possible.
Now let’s get back to the 21 ways in which you can keep your sourdough starter warm.
21 Ways to Keep Your Sourdough Starter Warm
1. Keep It in the Oven With Light On
Keeping your sourdough starter in the oven with the light on is an effective way to keep it warm. The oven light provides a low level of heat that is enough to maintain the warmth of your sourdough starter. Ensure that you do not accidentally turn on the oven while the starter is inside.
Another tip is to keep the oven door slightly open to allow for ventilation and avoid overheating the sourdough starter. This method works best if you have a gas oven with a pilot light, but it can also work with electric ovens. Remember to check the temperature regularly to ensure that it is not too hot or cold.
2. Put It on a Seed Raising Mat
A seed raising mat is designed to provide heat to seeds and seedlings to help them germinate. It can also be used to keep your sourdough starter warm. Place the seed raising mat under the container with your starter, and it will provide gentle, consistent heat.
This method is ideal for those who want to maintain a consistent temperature without worrying about monitoring the temperature regularly. A seed raising mat is relatively inexpensive and readily available in garden centers and online stores.
Here is a link to the one that I have. It’s quite cheap, it’s waterproof, and you can control the temperature.
3. Keep It Next to the Oven
If you have a busy kitchen, keeping your sourdough starter next to the oven can be an effective way to keep it warm. The heat from the oven is usually enough to keep the starter warm, especially if you are baking regularly.
However, be careful not to put the sourdough starter too close to the oven or on top of it, as it can become too hot. It is best to keep it on the counter next to the oven or on a shelf above it.
4. Cover It With a Tea Cosy
Covering your sourdough starter with a tea cosy can help maintain its warmth. A tea cosy is a fabric cover that fits over a teapot, keeping it warm. It can also be used to cover your sourdough starter container.
This method works best when combined with other techniques, such as keeping the starter next to the oven or using a seed raising mat. It provides an extra layer of insulation, keeping the heat inside the container. You can use a knitted tea cosy or make one yourself using an old sweater or wool fabric. Or if you want your starter to look nice, you can browse one of the hundreds of models available on Amazon.
5. Keep It in the Slow Cooker
If you have a slow cooker, it can also be used to keep your sourdough starter warm. Set the slow cooker on the “keep warm” setting, and place your container of starter inside.
After 15 to 20 minutes, you can stop the cooker and leave the starter inside it. The walls of the cooker at great at maintaining a constant temperature. So, turning it on once per day, when you feed the starter, should be enough to maintain a good temperature.
I have a cheap Crock-Pot 7 Manual Slow Cooker, and after 3 years it’ still doing a great job at keeping a good and warm temperature thorough the day, even after I’ve turned it off.
6. Use a Kombucha Jar Band
Kombucha jar bands are designed to hold a piece of cloth or paper towel over the top of a jar of fermenting kombucha. They can also be used to keep your sourdough starter warm.
Simply wrap the jar band around your container of starter and place a cloth or paper towel on top. This will help to insulate the container and keep the heat inside. It’s a simple and effective way to maintain the temperature of your sourdough starter.
If you don’t have a Kombucha jar you can get a starter kit on Amazon.
7. Feed It in Warm Water
If you’re looking for a simple and effective way to give your sourdough starter a temperature boost, try feeding it with warm water and placing it in a warm water bath. Feeding your starter with warm water, ideally between 37C to 40C (99F to 104F), can help to activate the wild yeast and beneficial bacteria in your starter jar, promoting fermentation and rise.
Additionally, you can create a warm water bath, fill a bowl with hot water from the tap, which should be around 50C (122F). While this might seem too hot, placing the jar of sourdough starter in the water will reduce the temperature to a warm and comfortable level for your starter. Keep in mind that you’ll need to change the water frequently as it cools down quickly, and avoid letting the water level get too high to prevent water from entering the jar.
Using warm water and a warm water bath can be an effective way to provide your sourdough starter with the warmth it needs to thrive. Just be sure to monitor the temperature regularly and adjust the water temperature as needed to maintain a consistent temperature.
8. Use a Heating Pad
A heating pad is another effective tool to keep your sourdough starter warm. Simply wrap the container of starter in a towel and place it on top of the heating pad. Set the heating pad to the lowest setting and check the temperature regularly to make sure it stays within the optimal range.
If you get a heating pad to keep your starter warm, the best part is that you can borrow it form your starter if you need a quick way to warm your feet or hands, or at least that’s what I do. Here is a link to the heating pad that me and my starter share.
9. Use an Instant Pot
Instant Pots are a popular kitchen tool that can also be used to keep your sourdough starter warm. Set the Instant Pot to the “yogurt” function, and place your container of starter inside. The Instant Pot will maintain a consistent temperature, making it perfect for keeping your sourdough starter warm.
An instant pot is not something that you buy just to keep your starter warm, there are a lot of cheaper alternatives. So if you decide to buy one make sure to do your research. I for one, am a big fan of the Instant Duo Pots series, as I found their products very reliable and durable over time.
10. Place It in a Proofing Box
A proofing box is a specialized tool used for bread making that provides a warm, moist environment for dough to rise. It can also be used to keep your sourdough starter warm. Simply place your container of starter inside the proofing box, and set the temperature to the optimal range for your starter.
Using a proofing box ensures consistent warmth and humidity, which is ideal for maintaining the temperature of your sourdough starter. This is especially useful in colder environments or during the winter months, when temperatures can fluctuate more dramatically.
11. Make Your Own DIY Proofing Box
If you don’t have a proofing box, you can easily make your own with just a few simple materials. Start with a large plastic container, and place a smaller container of warm water inside. Place your container of sourdough starter next to the smaller container of water, and close the lid. The warm water will provide the necessary humidity, while the container will keep the heat inside.
To maintain the temperature, you can also use a thermometer to check the temperature inside the box. Adjust the amount of warm water as needed to keep the temperature consistent. This is a great DIY solution that requires minimal equipment and is easy to set up.
12. Put It in the Yogurt Maker
If you have a yogurt maker, it can also be used to keep your sourdough starter warm. Simply place the container of starter inside the yogurt maker and turn it on. The consistent warmth of the yogurt maker will help to maintain the temperature of your starter, without the need for any additional equipment or supervision.
13. Use the Microwave
Maintaining the warmth of your sourdough starter using a microwave is a simple and quick option. You can usually warm your sourdough starter jar by placing it in the microwave and leaving the door slightly open to keep the light on. This generates enough warmth to keep your starter active. However, if your sourdough starter doesn’t rise in the microwave, adding a mug of hot water or a warm wheat pack is a great idea to boost the temperature and encourage activity.
To use a mug of hot water, simply heat water in a mug in the microwave for a minute or two and place the mug next to your sourdough starter jar. The heat from the water will help keep the sourdough starter warm and active. Alternatively, you can warm a wheat pack in the microwave according to the manufacturer’s instructions and then place it next to your sourdough starter jar to provide warmth.
14. Keep it Covered Near a Window
Another easy way to keep your sourdough starter warm is to place it near a bright window. The sun’s rays can provide a gentle source of warmth, especially in the morning or early afternoon when the sun is strongest. To prevent direct sunlight from hitting the container, place it in a covered area near the window, such as on a shelf or countertop.
Keep in mind that the temperature near the window may fluctuate throughout the day, so it’s important to monitor the temperature regularly and adjust as needed. This method works best in combination with other methods, such as a seed raising mat or tea cosy, to maintain a consistent temperature over a longer period of time.
15. Keep It Near a Kettle
If you’re boiling water for tea or coffee, why not use that heat to keep your sourdough starter warm? Simply place your container of starter next to the kettle while it’s boiling, and the residual heat will help to maintain the temperature. This is a great method if you’re short on space or equipment, and it’s also energy-efficient.
Be sure to monitor the temperature regularly, as the heat from the kettle may not be sufficient to maintain the temperature over a longer period of time. This method works best for short periods of time, such as while you’re preparing other ingredients for your sourdough bread.
16. Keep It in the Car
If you’re looking for a way to keep your sourdough starter warm while you’re on the go, consider keeping it in your car. The temperature inside your car can be warmer than the temperature outside, especially if it’s parked in the sun or a sheltered area. Simply place your container of starter in a secure location, such as the trunk or back seat, and close the windows and doors to keep the heat inside.
Keep in mind that this method may not be suitable for all climates or temperatures, and it’s important to monitor the temperature regularly to ensure the health of your sourdough starter. This method works best for short periods of time, such as while you’re running errands or traveling to a friend’s house to bake bread.
17. Keep It in a High Place
Heat rises, which means that placing your sourdough starter in a high place can help to keep it warm. Try placing your container of starter on a high shelf or countertop, or even on top of the refrigerator. This method works particularly well in kitchens with high ceilings, as the warm air from cooking and baking can also help to keep the starter warm.
Be sure to keep an eye on the temperature and adjust as needed, as the temperature may vary depending on the height and location of the container. Additionally, make sure that the container is securely placed to prevent it from falling or being knocked over.
18. Keep It in the Airing Cupboard
In some homes, there may be a cupboard or closet that’s designed to store linens and towels, known as an airing cupboard. This cupboard is typically located in a warm part of the house, such as near a hot water tank or central heating system. If you have an airing cupboard in your home, it can be a great place to keep your sourdough starter warm.
Simply place your container of starter in the airing cupboard and close the door. The warm air from the hot water tank or central heating system will help to maintain the temperature, providing a consistent source of warmth for your starter. Be sure to monitor the temperature regularly and adjust as needed, as the temperature may vary depending on the location and ventilation of the airing cupboard.
19. Keep It in a Crock Pot
If you have a crock pot or slow cooker, you can use it to keep your sourdough starter warm. Simply place your container of starter in the crock pot and turn it on to the lowest setting for a few minutes.
Crock pots usually have thick walls that are great at maintaining heat, which makes them a great place to keep your sourdough starter.
20. Use Heat Packs
Heat packs are a great option for keeping your sourdough starter warm if you need to transport it or if you don’t have access to a warm location in your home. Simply heat up a heat pack according to the instructions and place it in a container with your sourdough starter. The heat from the pack will help to maintain a consistent temperature for your starter.
Be sure to monitor the temperature regularly and adjust the number of heat packs used to maintain a consistent temperature. Additionally, make sure that the heat pack is not too hot and that the container is securely closed to prevent any leaks or spills.
21. Use a Fermentation Crock
Fermentation crocks are specialized containers designed for fermenting foods, such as sauerkraut and pickles. However, they can also be used to keep your sourdough starter warm. The thick walls of the crock provide insulation, which helps to maintain a consistent temperature for your starter. Additionally, some fermentation crocks come with a water seal, which helps to prevent oxygen from getting in and contaminants from getting out.
To use a fermentation crock for your sourdough starter, simply place your starter in the crock and close the lid. Place the crock in a warm location, such as near a window or in a warm room. Be sure to monitor the temperature regularly and adjust the location of the crock as needed to maintain a consistent temperature.
22. Use a Warm Beverage Cooler
If you have a warm beverage cooler, such as one used for keeping coffee or tea warm, you can also use it to keep your sourdough starter warm. Simply place your container of starter in the cooler and adjust the temperature to the lowest setting. The cooler will provide a consistent source of low heat, which is perfect for keeping your starter warm without overheating it.
Be sure to monitor the temperature regularly and adjust the settings as needed to maintain a consistent temperature. Additionally, make sure that the container is securely placed in the cooler to prevent it from tipping over.
23. Use a Heating Lamp
A heating lamp can be a great option for keeping your sourdough starter warm if you don’t have a warm location in your home. You can use a desk lamp with a heating element or a reptile heating lamp to provide warmth to your starter. Simply place your container of starter under the lamp and adjust the height to maintain a consistent temperature.
Be sure to monitor the temperature regularly and adjust the height of the lamp or the wattage of the bulb as needed to maintain a consistent temperature. Additionally, make sure that the lamp is placed on a stable surface and that the container is not too close to the bulb to prevent overheating or burning.
Final Thoughts
Keeping your sourdough starter warm is crucial for the success of your sourdough bread baking. With these 23 ways to keep your sourdough starter warm, you can choose the method that works best for you and your home.
Remember, temperature is the key factor when it comes to sourdough starter growth. Maintaining the right temperature can be the difference between a thriving, active starter and a sluggish one. So, experiment with the different ways to keep your starter warm until you find the one that works best for you.
With a little bit of creativity, you can keep your sourdough starter warm and healthy year-round, and enjoy delicious, homemade sourdough bread whenever you want.
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