Is there any reason you cannot make mineralized topsoil during cooler months? I started a bag of it this weekend and evening temps get down into the 60's and daytime temps are in the 70-80's, I have no problem if this just means it takes longer to dry.
i did a huge batch here in the midwest with temps a bit cooler than what you described. It did take a while and while it is true that bacteria are more active at higher temps, the more moderate temps kept the soil from drying out rapidly. IME this provided an optimal environment for the mineralization process....go for it:biggrin: