General Principles

• Sourdough starter is a LIVING culture which must breathe (don't keep it in an airtight container for long) and eat (must be fed).
• Starters may be kept in the fridge but should be taken out a day before you want to feed it again.
• You could spread it flat and dry it before putting it in the fridge if you don't plan to use it in a long time. When you are ready to use it again you have to take it out and rehydrate it with water.
• Sourdough starter is either active (having been fed 6-10 hours before) or inactive (not recently fed).
• Active sourdough starter that is ready for use floats in water. Use a (silicone) tablespoon full to check this if you need to be sure.
• Active sourdough starter has grown and has several bubbles.

DO'S

• Keep inactive sourdough starter in an open glass container. Cover this with a moist (not wet) cotton or paper towel.
• Use silicone or wood to handle the sourdough starter.
• Keep at least 120 g (⅓ cup) of starter after each baking project so that you can feed it for future use.

DON'TS

• Don't use metal spoons or bowls. Metal inhibits the culture growth.
• Don't store in plastic bowls. The acidic starter slowly absorbs plastic.
• Never use bleached flour.

HOW MUCH STARTER DO I NEED?

• Some recipes may include instructions on how to feed your starter. In those cases, follow these.
• Some recipes may just list how much active sourdough starter you need. When you calculate how much starter you need to make, be sure to calculate that you have at least 120 g (⅓ cup) of starter left over at the end (for future use).

FEEDING THE STARTER 1:1:1

• There are different ways and ratios to do this. I find the easiest is the 1:1:1 feeding ratio.
• Take the same part inactive starter (in grams) and add in the same part of lukewarm water (in grams). Combine with silicone spoon until milky. Add the same part (in grams) flour. Ideally you would use whole wheat flour for feedings. If not 100% whole wheat flour, then at least 25-50% of the flour used.

FEEDING THE STARTER 1:1:1 - concrete example

Ingredients

• 120 g inactive starter (= ⅓ cup)
• 120 g lukewarm water (= ½ cup), 70℉-85℉ (21℃-29℃)
• 120 g unbleached flour (= ¾ cup), use at least 25% whole wheat flour (e.g. 30 g whole wheat + 90 g white flour), may use 100% whole what flour

Feeding

• In a tall glass container, combine the starter with the water until milky. Use silicone or wood.
• Fold the flour in and combine until even.
• Make sure there is enough room on top for the starter to double in size.
• Cover with a moist (not wet) cotton or paper towel and let rest at room temperature.
• Starter is active after 6-10 hours. It will have increased in size and you will see bubbles.