Rye contains a different protein that also forms webs (differently) to retain gas bubbles.
Even among species of wheat, different levels of gluten produce bread that rises differently.
This makes it easy to grow more to share with others.
This also applies to grains that will not rise, such as barley or oats.
Other good sources are GEM cultures ( and Cultures for Health ( which also sells through
All of these cultures take a little work to get started, but they will last indefinitely if cared for and fed properly.
Sourdoughs International ( is one of the oldest commercial sources of cultures.
The company was founded by Ed Wood, the author of ) and sells a dozen or more different cultures collected from around the world.
The farther North you travel, the less wheat is likely to be grown. There are several ways of breaking down the starch in grains into less complex molecules that we can taste.