The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

TIPS: How to keep your sourdough starter warm

cranbo's picture
cranbo

TIPS: How to keep your sourdough starter warm

A recent TFL forum post inspired me to think about ways to keep your starter warm. 

Maintaining a warm temperature is extremely important to establishing a new starter. If you maintain your initial starter temperature at 82-86F, this will lead to the production of more lactobacillus than yeast, meaning a more sour/acid environment, which is important to establishing a healthy yeast and bacteria colony in your starter, especially at the beginning. 

Once established, maintain your starter between 72-80F; this will help improve the speed of yeast growth. Want more lactobacillus, or more yeast activity? Take a look at this handy chart of yeast and lactobacillus growth, and choose the starter temperature that will work best for what you're trying to achieve. 

I live in a part of Southern California where the weather is 75F on average about 300 days out of the year, so home warmth is generally not a problem. But what if you live where it's cold in the winter? Here are 7 ideas for how to keep your starter warm when it's cold

Sunny spot by a window. Easy and cheap, with one caveat: place your starter in a shoebox or other opaque or dark-colored box. Yeast and direct sunlight don't mix well. Of course dark colors will also help keep the box nice and warm in the sun too. 

Use a water bath. Use a hotplate, slow cooker or aquarium tank heater to maintain a water bath at the right temperature, and submerge your starter container (or ziploc bag) in the warm water bath.  

Cardboard or plastic box with a lamp. Run a low-wattage incandescent lamp/light bulb into a sealed box, turn the lamp on, and position your starter somewhat away from the lamp. A cardboard box or ubiquitous 20gallon plastic bin could be useful for this. 

Use your oven light. Simple as that: keep your starter in your oven with only the oven light turned on. It's easy to adjust the temperature by how close you place your starter container to the light. 

Next to your home heating system. Put it next to your home heating vent, wood stove, home furnace, fireplace, etc. 

Old miner style/next to your body: put your starter in a small double-bagged ziploc bag, and keep it close to your body, in a shirt or jacket pocket. Just like the "old sourdoughs" used to do when prospecting. This option is the most affectionate method, and results in the most bonding with your starter ;) 

Brod & Taylor Proofer. A lovely and functional option, if somewhat expensive. The Lexus of home proofing and warming options. 

Any other ideas I missed? I'd love to hear 'em. 

 

Comments

alfanso's picture
alfanso

Heating pad with a variable temp. control.

cranbo's picture
cranbo

Yes, this is a very good one. Affordable and serves multiple purposes.  

pmccool's picture
pmccool

With a container of hot water as the heat source.  If you leave the hot water uncovered, your proofer is humidified, too. 

Paul

cranbo's picture
cranbo

Thanks Paul, yes this is a great idea too. How long can the cooler maintain that nice warm temp? I've never tried it. 

For proofing, I often use a 4c. Pyrex with boiling water in my microwave oven with the loaves, but I find that this doesn't maintain sufficiently warm temp for more than about 1 hour. 

My concern for building or maintaining a starter is that it wouldn't stay warm long enough. Am I wrong here?

pmccool's picture
pmccool

How well insulated the cooler is, room temperature, dough quantity and temperature, water quantity and temperature.  I don't think that phases of the moon have an effect, though...

Prior to buying a B&T proofer, I could park a 1 quart jar of 115-120F water and a 1kg or thereabouts quantity of dough in a cooler with a 30-40 quart capacity and have it maintain temperatures (not measured) that were warm enough to keep the dough happy for at least an hour, maybe longer.  This with room temperatures in the 65-68F range.  More or hotter water would obviously extend the duration.  Repeatedly opening the cooler will shorten the duration.  And so on.

Paul

suave's picture
suave

I don't see why that would be true.

dabrownman's picture
dabrownman

ultra violet light is used to purify water and kill bacteria.  Works really good and direct sunlight isn't a good thing for the wee beasties,

suave's picture
suave

That's UVC light which has wavelength of 254 nm.  It is effectively absorbed by the ozone layer and never reaches earth surface in notable amounts.  Windows filter out whatever little that does.

cranbo's picture
cranbo

I was trying to find some other more definitive references on this, all I could find is this:

http://www.livestrong.com/article/252729-the-effects-of-uv-light-on-yeast/

Some UV light can be good for yeast, while large amounts can kill yeast. Is leaving your starter in direct sunlight for 6-8 hours each day going to kill your starter, or slow it down? Don't know. 

I always thought this was one reason that commercial yeast packets are sealed in opaque foil, and yeast jars are dark glass/opaque. 

Toad.de.b's picture
Toad.de.b

Missing from your list of "home heating system" options is my (and my starter's) favorite 'warm spot':  Snuggled up against the copper outlet pipe of our water heater tank (conveniently just off the kitchen), with an old wool stocking cap dropped over the stock starter jar or levain vessel.  I've even mounted a now always-warm ceramic tile to rest on top of that pipe after it turns 90˚ and runs horizontally to the wall.  Great place for proofing dough in loaf pans and bannetons, putting to good use a few of the beaucoup BTUs wasted by these dinosaurian legacies of America's halcyon cheap energy days.

Tom

cranbo's picture
cranbo

Love it! Another great suggestion, thanks Tom. 

Mebake's picture
Mebake

Useful thread , Cranbo. Thanks!

On a Refrigerator, towards the back. This is usually warm.

Khalid

cranbo's picture
cranbo

Khalid, that's a good one too. Now that I think about it, this is where I usually keep my starter at room temp. Can't believe I overlooked the most obvious answer from my own experience! :) Thanks for reminding me

yolofitz's picture
yolofitz

Only because I own a Joule sous vide circulator.....In a 5 quart sauce pan almost full of water, I placed the small glass jar with starter on top of a 15 oz can of beans so that the starter is slightly below water level. Joule is set to 80F. 

cranbo's picture
cranbo

Great idea! Sous vide would be perfect for this.