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Milk Kefir Sourdough starter in a jar with milk kefir in the background
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5 from 9 votes

Milk Kefir Sourdough Starter

Want to get started with sourdough? Try this extra quick and easy milk kefir sourdough starter that's ready in about one day!
Prep Time3 minutes
Minimum Fermenting Time:12 hours
Total Time12 hours 3 minutes
Course: Meal Prep
Cuisine: American
Diet: Gluten Free, Vegetarian
Servings: 1 sourdough starter
Calories: 242kcal


  • 1 glass jar


Initial Starter Materials:

  • 2 ounces flour (~½ cup, measure by weight if possible) See "Flour Tips" Recipe Notes
  • 2 ounces milk kefir (plain with live cultures) See "Milk Kefir" Recipe Notes

Starter Maintenance (Optional):

  • 2 ounces flour (~½ cup, measure by weight if possible) Use same flour as original starter, or slowly transition to another type of flour
  • 2 ounces non-chlorinated water (¼ cup)


Initial Starter:

  • In a clean glass jar, whisk together the flour and milk kefir. (I like to use a fork to whisk.)
    The mixture should be the consistency of pancake batter. If yours is much thicker, add a little more kefir to thin it out, or if it seems very thin add more flour. (I've found rice flour needs slightly more kefir.)
    Cover the jar. (Cover can be loose or air-tight, see "container tips" recipe notes.)
    Store jar in at room temperature (about 70°-75° F).
    Stir Together the Milk Kefir + Flour
  • Stir the flour and kefir once or twice a day, until the starter is bubbly and has doubled in size.
    Your starter should be ready to use within about 24 to 48 hours. You should have approximately 1 cup of starter.
    Add to a Glass Jar
  • No Maintenance Starter: You can proceed to use the entire batch in a recipe, skipping any starter maintenance, and simply remake the starter as desired. This is a nice option if you don't want to maintain a starter, or if you're using a gluten-free flour that may be difficult to maintain.
    "Float Test" for Bread: Once the starter has doubled in size and is bubbly, it should have a nice enough flavor to use the discard right away in discard recipes. To test if the starter is ready for bread, pinch of a small piece of the starter and drop it in water. If it floats, it can be used in bread. If it doesn't, proceed to the starter maintenance stage and keep feeding the starter until it passes the float test.
    Active Sourdough Starter

Starter Maintenance:

  • Discard the starter down to 2 ounces (~½ cup). You can use the discard in a "discard" recipe.
    Whisk together 2 ounces of flour, 2 ounces of water and 2 ounces of starter. Note that from this point on, you can feed the starter with water instead of milk kefir.
    Cover the jar, whisking once or twice a day. When the starter is bubbling and doubled in size, repeat the process.
    Continue discarding and feeding once a day, or place into storage until ready to use again.
    To store the starter: Feed the starter and then move it immediately into the fridge. Remove from the fridge and allow the starter to warm up for a few hours before using. Depending on how long the starter was in the fridge, it may take a few days to become very active again. Ideally, feed starter at least once a week even when in storage.
    Sourdough Fermentation Bubbles


Flour Tips:
  • Unbleached all-purpose flour is perfect for your starter.  It's less finicky than some other flours.
  • Gluten-free flours (such as rice flour, sorghum flour, millet flour and arrowroot flour) will work to varying degrees, but may be much more difficult to maintain.  Avoid using gluten-free flours with xanthan gum (a thickening additive).  Avoid using nut flours (such as almond flour), as these likely will not work.
  • If possible, use organic flour.  It will be easier for the good bacteria to grow with organic flour.
Milk Kefir Tips:
  • Use plain, unflavored milk kefir with live probiotics.
  • This technique will likely work best with homemade milk kefir.
  • Do not add milk kefir grains to the flour, only the liquid kefir.
  • This technique should also work with unflavored water kefir, but I haven't personally tried that.
Water Tips:
  • Use non-chlorinated water.  (Chlorine will discourage, or even finish off, the good bacteria you're trying to grow.) 
  • Non-filtered tap water is generally chlorinated.  I use a reverse osmosis filter for my water, but filtered water should work just fine.
Temperature Tips:
  • If your kitchen is cold, your sourdough starter may struggle to get started.  Try placing your starter somewhere warm (like on top of your fridge). 
  • For a cold kitchen, try using warm (not hot) water for your starter maintenance.  Hot water can ruin your starter.
Container Tips:
  • My preference is to loosely cover the jar.  You can use a paper towel and a rubber band, or a jar with a non-air-tight lid.  I use a swing-top jar with the rubber seal removed.
  • If you use a loosely fitting lid, you may find that your sourdough starter will sometimes develop a thin skin on top.  This is simply dried-out dough.  You can peel it off or stir it back in, but it won't harm your dough (or your baked goods).
  • If you choose to ferment or store your sourdough in an air-tight container, make sure that there is plenty of room for the dough to expand.  If the jar is too small, the sourdough could burst out of the jar (or even bust the jar itself), creating quite a mess.
Discard uses + storage: The discard can be used right away or frozen in batches and saved for discard recipes.  You don't actually have to "discard" it.
General Sourdough Tips:
  • Keep it clean.  Make sure to always use clean utensils and jars when working with sourdough.  Contaminating the dough can cause problems.
  • Liquid on top of the starter.  If you see liquid on top of your starter, it's called hooch.  Drain it off and feed your starter immediately.  I've typically only had problems with hooch when I was adding too much liquid to the starter.
  • Measure the flour by weight if possible.  Ideally, use a digital scale, but I've had success with even a cheap analog scale.  One cup of all-purpose flour does not weigh the same as one cup of whole wheat flour, so it can be harder to know how much liquid to add without using a scale.  If using unequal amounts of flour and water, you could have problems with hooch (see above), or simply less consistent results.
Nutrition information includes 2 ounces of flour and 2 ounces of milk kefir. 


Calories: 242kcal | Carbohydrates: 46g | Protein: 8g | Fat: 2g | Saturated Fat: 1g | Cholesterol: 7mg | Sodium: 31mg | Potassium: 61mg | Fiber: 2g | Sugar: 3g | Vitamin A: 116IU | Calcium: 79mg | Iron: 3mg