To start:
Mix 1/2 cup whole wheat flour with 1/4 cup of clean, warm water. I use a quart-size mason jar.
Put a lid or plastic wrap over top and place your container in a warm spot for about 24 hours (warmer is better as long as it's not getting cooked. Inside the oven, maybe with the light on for awhile, is a good spot as long as the oven's off, or just on top of the fridge if you live in a warm place).
Check for bubbles. Your culture should be starting to come alive now! If it is, take the lid off and cover loosely with a tea towel for another 24 hours.
You may start to see some liquid the second day, and the odor may be stronger. Typically this means the starter needs to be fed, and that liquid (the hooch) would be drained off. Leave it for today though, and start feeding the next day.
To feed:
After those first three days, it's time to start the feeding cycle! Discard that layer of liquid and any other discoloration that may have occured.
I usually put my starter in a new container when I feed it, this isn't necessary every time though. Just make sure your edges are clean.
Add a 1/2 cup of flour and 1/4 cup of warm water to your starter and mix together well. You just fed your starter!
Again cover well with a loose dish/tea towel, and store in a warm-room temp place.
Notes:
🔸We use our starter at least twice a week, so I pour whatever I need into my mixing bowl, the rest into a new jar and then feed it in the new jar. When we go away, I put it in the fridge which slows down growth exponentialy so it doesn't need to be fed till we get home again.