German recipes frequently add salt to building the levain or preferment whereas I don’t see it mentioned in North American recipes or the two books that i have (Forkish K. “Flow,water salt, yeast.” and Hadjiandreou E. “How to make bread”.) Any thoughts on this?
Thanks
Too much salt in a starter will slow it down. Wherever it's added doesn't really matter - it'll break down and be used over time. Enjoy!
Salt will help reduce degradation of the protein in the dough. If you plan a long build cycle for a levain or preferment, and then a long fermentation cycle, this might be the place to use salt. I know from experience that 2% salt in a starter will not cause the starter to deteriorate, so I'm sure that the same amount in the preferment will be fine. Of course, it will slow down development, which may or may not be what you want.
Otherwise, putting the salt in early tends to cause the dough to be stiffer and more elastic. Delaying the salt tends to produce a more extensible dough. For a long fermentation this really won't matter but it can for short ones.
TomP