I haven't used more than 12% cara red in any beer and when I have used it I have left out crystal malt completely. In face, while I do keep some crystal malt on hand most of my recipes I don't use it very often, and when I do it is never over 5%. Crystal malt is a great tool, but for some reason most homebrewers (and far too many commercial brewers, as well) tend to add it to everything. Also, unless I am brewing a lower gravity beer I mash almost all my beers between 148-150.