I have been reading up on teas and noticed that some people say that "foam is an indication of biological activity", but I've also heard that foam or no foam is "no big deal,either way".
What do you say
Actually foam isn't an indication of biological activity. It's actually a sign of decent amounts of proteins in the compost you are using (mostly decayed worms). All types of compost even regular top soils can be used to create the same microbial life in compost teas. So don't worry that it's not foaming.