Does anyone else do this? About every 4th or 5th beer I brew I’ll incorporate this technique when I don’t have a 4-5 hour window to brew. I’ll mash in just before going to bed, insulate the kettle (I BIAB) as best I can, then finish the brewing process in the AM. Depending on the season I find that the mash drops 30-40F overnight. My mash efficiencies are generally 5% higher using this method and I haven’t had any ill effects from this. I don’t have the equipment (or enough desire) to do an experiment testing the results of an overnight mash on beer taste compared to a traditional mash.
I wonder if since the temp is dropping from the low 150F’s to 115F or so if there is any “reverse step mash” effect going on?? Just curious what others think as I have extra time on my hands these days thanks to Covid-19