Leaven Testing and Mixing

The best test for determining whether or not your leaven is ready to mix with is what is known as the “float” test. It’s pretty simple: take a fist full of leaven and place it in a bowl of water. If it floats, the leaven has enough aeration and bacterial activity to put levity into your bread. If your leaven sinks, put it back in the bowl and place in a warm spot for another hour or so. After 12 hours, your leaven will almost always be ready to go; however, during colder seasons it may take up to 15 hours. One way around this time difference is to build your leaven with slightly warmer (never hot!) water. This will speed along the fermentation.

Once your leaven is ready, commence mixing the dough for your recipe. As far as ratios are concerned, your amount of leaven (by weight) should be approximately 20% of the weight of flour called for by your recipe. For example, if your recipe calls for 100g of flour, you will want to add 20g of your leaven. Bakers will commonly write recipes that deal in ratios that are proportionate to the total amount of flour. So when a baker talks about a dough that is roughly “70% hydrated”, They mean that for every 100g of flour, there is 70g of water. A typical formula for sourdough recipes is as follows:

  • 100g Flour
  • 65-70g Water
  • 20g Leaven
  • 2g Salt

Naturally, the type of flour(s), the addition of whole or ground grains, or the addition of honey to the recipe will have an effect on the recommended hydration percentage. Whole wheat flour and whole grains will tend to absorb water as the dough rests. Dough with lots of grains or a high percentage of whole wheat often feel extremely wet at the start but dry up as they proof and undergo folding. Dough with honey will require slightly less water. As stated in the beginning, this is just a guideline. All of these proportions can be manipulated to suit your tastes (especially the salt percentage).


For mixing, I have found it easiest to mix by hand and follow a certain order for adding your ingredients. In a glass bowl, start by adding your water. For a shorter proofing period or for mixing in a cold environment, use water slightly warmer than room temperature (lukewarm) but never hot! In warmer areas, you may want to use water that is slightly cooler than room temperature, but not too cold to the point where it’s uncomfortable to keep your hand in the water. Next, add your leaven and break it apart with your fingers until it’s somewhat dispersed and the water appears cloudy. Add your honey at this point, if the recipe calls for it. Next, add your flours. You may start by adding half and work in the rest slowly, or you can go all at once. It depends on how wet your dough is (and on how strong your hands are). DO NOT add your salt yet. Mix by squishing the ingredients between your fingers until all the ingredients just barely come together to form a uniform texture.


In my next post I’ll explain the next steps: Salting and Folding.