- To make barm you take 1 cup from your seed culture (give away or discard the rest) and mix it with 3 1/2 cups high gluten/bread flour and 2 cups water.
- Transfer the barm to a large clear container at least twice its volume.
- Let it sit out on the counter until it bubbles and rises some, then put it in the refrigerator.
- If you do not use it in the following three days (or if you use more than half) you will need to refresh it.
If don't plan on using the barm to make bread soon you can leave it in the refrigerator for up the 2 months and refresh it 1 or 2 days before using. You can also freeze it for up to 6 months and leave it to defrost overnight in the refrigerator three days before using it. Then refresh it
Sorry this post took so long. I completely forgot to publish it!
Leaving the barm in the refrigerator will not make it become sour. To do that, you must leave it out on the counter (or somewhere else will a relatively constant temperature) and refresh it every 3-4 days.