Category Archives: Sourdough

Caring for your yeast baby

In order to keep a sourdough starter (“yeast baby”) viable for baking purposes, it is necessary to feed it regularly. The more consistent you are with the feeding schedule, the more reliable your starter will be for baking delicious breads (and other things, too).

Required stuff:
-Jar of sourdough starter
-Clean spare jar
-Kitchen scale that weighs grams
-Bag of unbleached white flour
-Container of filtered water

The golden rule is a 1:1:1 ratio — to take one part by weight of the existing sourdough starter and add to it one part flour and one part water. Mix that all together into a clean jar until there are no dry lumps of flour. I like to use a regular table knife to mix with since it’s easy to scrape off.

If you are not going to be baking in the near future, use a minimal weight, like 15g of each the existing starter, flour, and water. Keep that jar in the refrigerator for up to a week before you feed it again. You can use the leftover starter to make pancakes, start a backup batch, or just throw it out.

If you are going to be baking, you will need to figure out how much starter the recipe calls for and divide that by 3, with some left over for continuing the starter. For example if we wanted to make my standard sourdough loaf, it calls for 120g of starter, which requires 40g starter from the jar, 40g flour, and 40g of water (40+40+40=120). But we’d also want about 15g extra starter to keep the starter going in the jar. Weigh out whatever you have left from the jar of starter, whether it is 15g or less, and add equal parts flour and water to it. Be aware that if you end up with less than 5g of your starter to continue on with, you may fundamentally change the character of it going forward.

After feeding, let the yeast baby sit for two to five hours until it has doubled. It is called “fed” starter after it has roughly doubled. This is when you should put it to use.

Things can go wrong. I tend to keep at least one backup jar of starter in the fridge in case I break the jar, or somebody mistakenly throws it out, or I feed it almond flour because I’m too tired to realize what container is in my hand.

If your sourdough starter starts developing odd colored blotches, it could be mold. If this is your only starter and it is mature (usable for baking), take a portion of an unaffected area and start again with that. It may have been caused by contamination or too warm an environment. It could also be weird blotches from using a flour that isn’t entirely pure, like a malted flour or enriched flour. If that’s the case, just switch to using just 100% pure unbleached white flour.

If your yeast baby develops a layer of liquid along the top, it is alcohol and you are starving it of precious nutrients. Pour off the alcohol and give it more consistent feedings. It should recover, but it may taste different.

Temperature will impact the kind of yeast that dominates. You may find that you prefer the flavor or behavior of a sourdough starter that’s kept mostly in the fridge versus one kept mostly at room temperature, or vice versa. You also can slightly vary the amount of water away from a 1:1:1 ratio to favor different types of yeast. Knowing the specific impacts on types of yeast is beyond my expertise, so I would encourage you to turn to your own research if you’d like to know more about that.

Starting a sourdough culture

Starting a “sourdough starter,” “sourdough culture,” “mother,” or “yeast baby” as I prefer, just takes some patience and persistence. You’ll need a kitchen scale to weight grams and two clean jars. One jar will hold the current batch of starter, and you will transfer just a bit of that starter into a new batch with some equal parts water and flour in order to “feed” it. Here’s a summary of what I did:

From scratch, find a clean wide-mouth jar, and rinse it thoroughly so that there is no detergent left in it. Mix in 15g flour and 15g water until it is roughly consistent in texture with no dry clumps of flour. Put it somewhere warm and dark. Wait a day. Transfer 15g of this mixture into a clean jar and add 15g flour and 15g water to it. This is called “feeding.” Keep repeating this cycle until you think you’ve lost patience. At first it will smell like boring dough, and then maybe after a week or two you’ll hit this really, really funky smell, like rotting wet socks at the bottom of a garbage can. But keep going through this stinky phase — it will start to mellow out and develop into something that still smells sour but not offensive. When you think it may be starting to mature, probably around week 3, draw a line at the top of the mixture and check back a few hours after you’ve fed it and see if it has doubled in height. If it has doubled, you’re done starting the starter! If not, keep at it, because it may take a bit longer to develop into something usable for baking.

Some people claim that there are shortcuts, like using different kinds of flour mixed in (particularly rye), or a bit of fruit juice of some sort (like pineapple). I haven’t tried these because I just hammered on with the above pattern for a month and got a really nice yeast baby that’s been with me for a few years now. My next post will be about continuing care of your yeast baby.


This recipe is for one round-shaped sourdough loaf. You can adapt it to other forms, and I encourage you to experiment with different mixes of flours. The key thing that I’ve learned with wrangling sourdough breads it that there is a lot of room for experimentation, and failure often looks ugly but ends up tasting pretty good anyway.

If you don’t already have a sourdough starter, here are instructions for starting one.

I’m sharing this under CC BY 3.0. If you would like to repost the content of this recipe elsewhere, I would just ask for a link back to this page at

I’m writing this post from Olympia, Washington, with easy access to artesian well water which seems to make my sourdough culture (“yeast baby”) very happy. If you have access to a natural spring or decent well water, congrats! You’re extremely lucky. If not, you may want to try filtering your tap water and de-chlorinating it. I have resorted to bottled spring water in the past but its environmental effects are hard to justify.

Required hardware:

  • Kitchen scale that measures grams
  • Mixing bowl
  • Whisk
  • Knife (regular dinner table one, not a blade), spatula, or wooden spoon for mixing dough
  • Baking stone or cast iron pan
  • Baking tray/pan for holding water that adds moisture to the oven baking environment
  • Banneton (basket), or medium sized bowl and clean dish towel (not a fuzzy one) for final shaping
  • Bread knife (long knife with serrated blade)

Optional hardware:

  • Dough scraper (makes working with sticky dough easier)
  • Plate to cover the mixing bowl (to avoid plastic wrap)


White bread:

  • 500g bread flour (I use Giusto’s Organic Ultimate Performer Unbleached Flour when I can find it)
  • 345g water
  • 120g fed sourdough starter
  • 10g salt mixed into 15g water
  • Corn meal for dusting the baking stone

Whole wheat rye:

  • 250g white bread flour
  • 200g whole wheat flour
  • 50g rye flour
  • 355g water
  • 120g fed sourdough starter
  • 10g salt mixed into 15g water
  • Corn meal for dusting the baking stone
  • A separate mixing bowl to mix the different flours together


Pour the water into the mixing bowl (just the plain water, not the salt water that we’ll add later).

Mix the sourdough starter into the water with a whisk.

If you are using a mix of flours, first mix them together in a separate bowl from the water/sourdough mix.

Gradually add the flour into the sourdough/water mix. I like to use a knife for this part but you can use a wooden spoon or a spatula if you prefer that.

Once all of the flour is mixed in and the consistency is relatively even, let it sit for 5 minutes.

Start kneading the dough. Which method you use is entirely down to preference. Check out some youtube videos if you’d like some options. I prefer using a dough scraper at the beginning when the dough is most sticky, then letting it rest for a minute or two, and finishing kneading with my hands.

Turn (knead) the dough until it passes the window pane test.

Dump the salt water mixture on top of the dough and cover the mixing bowl. I use a plate that covers my mixing bowl nicely to avoid using plastic wrap. Let the dough sit covered until it has risen visibly (but not doubled). If we mixed in the salt at this point it would inhibit the yeast.

This stage is called “bulk fermentation”. If the ambient air temperature is warm (65°F+), opt for a shorter time. If the humidity is very low (dry air), you may want to sprinkle some extra water on top of the dough to prevent it from drying out and developing a skin (if it does develop a skin, it’s not the end of the world, but there may be little flaky or chunky bits in the final product — although sometimes they disappear after being mixed in and sitting for long enough).

After it has risen a bit, but not doubled, mix the dough by hand just enough to evenly distribute the salty water that we dumped on top.

Cover the dough again and let it sit for another hour to few hours (depending on ambient air temperature).

Check back on the dough and do the poke test.

Once the dough has passed the poke test, put it directly into the coldest part of your refrigerator — usually towards the back of the bottom shelf. If it looks very dry on top, sprinkle some water on top of it to prevent it developing a skin.

Let it sit there and slowly cold ferment for 12 to 48 hours. Longer than 48 hours can work if you have a very cold fridge (closer to but not quite freezing) and want a super tangy bread. Otherwise the dough may start to develop a layer of alcohol on the surface which indicates that the yeast is starting to become spent. You will have to experiment with how long of a cold fermentation you prefer based on baking qualities and taste. Generally the longer the fermentation, the more sour and tangy it will taste, up until a point where the dough is over-fermented and won’t rise nicely anymore in the oven.

Once you have finished cold fermenting your dough, pull it out of the mixing bowl and shape it roughly into a ball. It may need to rest a bit at room temperature in order to become pliable enough to shape. If you are using a banneton, lightly dust it with flour to prevent sticking and plop the dough ball into it. If you don’t have a banneton, take a clean dish towel (one without furry fibers) and lay it inside the bowl. Lightly dust it with flour and plop the dough ball inside the bowl. Then lightly dust the top and edges of the dough ball and wrap the sides of the dish towel over it. Make sure there is some dusting of flour covering all of the contact points with the towel so that it doesn’t stick when you’re trying to transfer it to the oven.

Let the dough sit in the banneton or bowl for about an hour at room temperature, or preferably longer and in the fridge, to take its final shape.

Place your baking stone or cast iron in the middle rack of the oven and preheat the oven to 430°F. Make sure there is enough room for the bread to rise between racks, so take out the top rack or move it out of the way.

After the oven has reached temperature, boil enough water to cover 1/4″-1/2″ of your baking sheet.

Place the baking sheet on the lower rack and pour the boiling water into it.

Dust the center of the baking stone (or cast iron) with corn meal to prevent the bread from sticking. If you really don’t like corn meal you can skip this part at the risk of your bread sticking or having a split bottom. I personally detest corn meal on my pizza but don’t mind it on the bottom of a loaf.

Take the dough ball out of its container upside down so that the wide part is on the bottom, and plop it dead center of the baking stone. The advantage of a banneton here is that you can transfer it directly from the basket onto the baking stone. With a bowl and towel I often have to catch the dough ball in my hands for a few seconds before placing it on the stone to avoid scorching the towel.

Score the top of the bread with a knife. I use a cross pattern (like a + sign) and tend to do a deep slash (about 1/2″) across the entire top. That way it avoids the loaf splitting during oven spring by defining channels for gas and moisture to escape from the dough while it bakes. You can experiment with your own patterns and depth. If your loaf still splits or has weird puffs, it could be due to under-proofing at some stage — not letting it sit long enough for bulk fermentation, or it may not have had enough time for final shaping in the bowl/banneton. It could also be that your sourdough starter is extremely potent, and you can try using less the next time around.

Let the bread bake for 30 minutes — or a little less if you have a convection oven. If you don’t have a convection oven, halfway through this initial baking period you may want to turn the bread around 180° to bake it evenly on the other side.

After 30 minutes, pull the pan of water out. Decrease the oven temperature to 350°F.

Bake for at least another 10 minutes. If you want a crisper and thicker crust, bake longer, up to 20 minutes or until the crust looks like the color you want, possibly with a reduced temperature, down to 275°F.

Turn the oven off when you think the crust is to your liking.

If you want a very moist crust, put the pan of water back into the oven and let it sit for a few minutes. Then as you take the warm bread out of the oven wrap it in a dish towel to prevent some of the moisture from escaping.

If you want to preserve a very crispy crust, pull the bread out and put it onto a cooling rack immediately; or if you don’t have a cooling rack, leave it in the oven with the door open until it cools off, at the risk of over-baking the bread a bit. Let it cool completely before slicing into it.

I hope you end up with the good results that I do. If not, yell at me in the comments. I’ll probably blame it on your sourdough culture though. 😉