Nice to see someone talk about a frothy head. As it is not a gauge to a quality tea. Temperature, and recently I have been testing wind speeds(if there is a breeze) play a huge role in the size of the frothy head. Last week I had a brew that did not have one single bubble on top anywhere, and under the scope it was one of the best brews I have seen this year. On the flip side I can brew a tea that has a giant frothy head that has next to no life in it. So the moral of the story is to buy a microscope so that you know what the fuck you are making. If not you need to use (or buy) a tested brewer, and use tested ingredients. If not you are wasting your time.
You can say all you want that if it smells earthy, and has a frothy head then it is a good brew, but you would be dead wrong.
Does it mean it is a bad brew? Will it hurt your plants? Most likely not. Is it bringing a shit ton of microbes to the table to boost nutrient cycling? That is the question. My time is money so I don't want to waste time doing something that I do not know for sure what it is actually doing. So many people on here are brewing teas with no idea what is in the tea.
Look at it this way. Would you purchase, and then use a bottled nute that smelled earthy, and had a frothy head, but the maker could not tell you anything about the product, or show any tests by which the product worked? I am guessing you would tell said company to suck a big fat cock. So then why do so many people act like their teas are the end all be all when they actually have no idea what the hell is in the tea?
"Oh I can tell a difference in my plants." Well fuck, bottle that shit up and sell it then son.:)