Why should I avoid glucose, table sugar, honey, apple juice, etc.in making yeast starters?
Brewer’s yeast has been selected for its ability to grow well in malt-based wort and produce pleasant by-products. In particular, yeast prefer to ferment maltose because it is the largest fermentable constituent in wort. Growing your yeast up in a non-malt environment can affect the health and you can get a disordered fermentation and possible off flavors in your beer. Growing up in a high glucose environment, for example, can result in selection in favor of respiratory mutants that cannot properly ferment maltose. As an analogy, consider how unhealthy you and your decendents would be if you were asked to live (and reproduce!) on a diet of nothing but soda pop.
