Measure 40 grams of bread flour into the jar followed by 10 grams of whole grain rye flour for a total of 50 grams of flour.

Now add 50 grams of water to the jar. We’ve added equal parts of flour and water by weight, 50 grams each. This is called a 100% hydration starter.

Mix the flours and water together and incorporate air into the mixture.

Clean down the sides of the jar with the spatula and place the lid loosely over the top.

Now place the jar in a warm spot of your house and let is sit for 48 hours before we do the first feeding.

What to Look for: The starter should have some bubbles present and may form a thin skin on top. It will not have a tell-tale sour smell of fermentation yet.

Measure 50 grams of the starter into a clean jar and discard the rest. Now we will feed it with 20 grams of bread flour and 5 grams of rye flour. That is 80% bread flour and 20% rye flour of the total amount of flour or 4 parts bread flour and 1 part rye flour. We will always feed our starter with this ratio of flours.

Then add 25 grams of water to the jar. So again we are adding equal amounts by weight of our flour mix and water, 25 grams each. Follow this ratio for every feeding: 2 parts starter to 1 part of total flour to 1 part water.

Mix it all together vigorously to incorporate air into the starter.

Cover the jar loosely and mark the level of the starter with a rubber band. Let it sit in a warm spot for 24 hours.

What to Look for: The starter should have increased yeast activity and should be almost doubled in volume. May start to smell sour, but still not a pleasant yeasty smell.

In the same jar, feed the starter with 50 grams of our 80/20 flour mix, so 40 grams of bread four and 10 grams of rye flour.

Then add 50 grams of water and mix together, incorporating air as you mix it.

Cover it loosely and mark the level of starter with a rubber band. Then let is rest in a warm spot for another 24 hours.

What to Look for: The starter should have about the same level of yeast activity. A skin may form and it will smell more and more sour.

Transfer 50 grams of the starer to a clean jar and discard the rest.

Feed it with 25 grams of our 80/20 flour mix, so 20 grams of bread four and 5 grams of rye flour.

Add 25 grams of water and and mix together, incorporating air as you mix it.

Cover it loosely and mark the level of starter with a rubber band. Then let is rest in a warm spot for another 24 hours.

What to Look for: The starter should have nearly tripled in volume and be very active with lots of bubbles. It should have a sour fermented scent by now. At this stage it should be ready to use after 1 more feeding.

Feed it in the same jar with 50 grams of our 80/20 flour mix, which comes out to 40 grams of bread four and 10 grams of rye flour.

Now add 50 grams of water and mix together.

Cover it loosely and mark the level of starter with a rubber band.

The starter should become very active and bubbly and double to triple in volume within 3 hours in a warm spot. It might take longer in a cooler environment.

If the starter has tripled in volume within 3 hours it is now very active and ready to use in recipes. You may have to feed it again to increase the amount of starter you have, depending on how much a recipe calls for.