How to Create a Sourdough Starter Completely From Scratch

Make your own sourdough starter in two weeks

Ingredients

• all purpose flour

• whole wheat flour or rye flour

• water - tap water or filtered water

Equipment

• glass jar - any jar will work but it’s nice to have a glass jar so you can see the activity of your starter 

• stirring utensil

• kitchen scale 

Directions

Day 1.

Add 20 g all purpose flour, 20 g rye flour and 40 g water to a jar. Stir until the flour is completely dissolved and use a spatula to clean the sides of the jar. Close the lid tightly. Leave on the table for 24 hours. Try to keep the temperature around 21-25 degrees Celsius.

• What to look for: after 24 hours, you should see a few small bubbles. If not, do not worry, just keep feeding!

Day 2.

Discard most of the starter, leaving about 20 g of starter in the jar. Add 20 g all purpose flour, 20 g rye flour and 40 g water to the jar. Stir and cover tightly with a lid. Leave on the counter for 24 hours.

• What to look for: At the end of the 2nd day, more bubbles should appear on the surface of your starter, but there should not be a sour odor yet, as the bacteria are just starting to develop. Your starter may pore or double in size on the 2nd or 3rd day, but after a few days it will stop doubling in size. Do not panic, this is normal.

Day 3-4 

Add 20 g of all purpose flour, 20 g of rye flour, and 40 g of water to the 20 g of starter in a jar. Stir until the flour is completely dissolved and cover tightly. Leave it on the table for 24 hours. Repeat this on days 3 and 4. If a crust from the starter appears in the jar, add 20 grams of starter to a clean jar before feeding and feed as usual with 40 g of flour and 40 g of water.

• What to look for: At this point, you should have a small colony of CO2 bubbles with a colony of natural yeast that is now multiplying in your starter! At this point, the smell is probably not very noticeable yet!

Day 5

If after 24 hours your starter smells strongly of acetone, foams and/or has a clear/black or gray liquid on top, it means that it is hungry between feedings and is ready to switch to twice daily feedings. The reason we increase the number of feedings is to prevent the starter from getting so hungry that it becomes susceptible to mold. The starter should start to smell and rise. The smell can be different: sauerkraut, cucumbers, kefir, or even chemicals.

• In the morning, add 20 g of all purpose flour, 20 g of rye flour, and 40 g of water to 20 g of starter and leave it for 12 hours. 

• The starter should double in size. If it's liquid and doesn't rise, you probably need to replace the flour or try again. If this happens, it means that this time the culture was not the one we needed. 

• In the evening, take 20 g of our starter and add 40 g of water and 40 g of flour (20 g all purpose flour, 20 g rye flour. Leave for 12 hours).

• What to look for: You will continue to watch the yeast colony grow, forming more and more bubbles, and at this point there is a good chance that your starter will start to rise.

Day 6-14

When feeding twice a day, continue to remove all but 20 g of the starter from the jar. Add 25 g of all purpose flour and 25 g of rye flour and 50 g of water. Stir and cover with a lid. Repeat the same after 12 hours. 

• Continue to change the jar every two days or as needed when it becomes crusty or dirty.

Signs that the starter is ready

Typically, the starter will be ready within 10-14 days. The starter is ready when it doubles in size or more with each addition of flour and water. It will also try to stick to the sides of the jar and will have bubbles on the sides and top. 

I recommend continuing to feed the starter daily for at least another week to make sure it is strong and healthy before placing it in the refrigerator if necessary.