Started a batch of Brown ale on Monday. Fermentation vigorously started within a couple hours. On day 3 it slowed waaaay down. Temps in my area are considerably cool for this time of year. Morning average low is 57 degrees. I have it fermenting in my bedroom closet. Could it be because of cool temps that yeast have slowed down? First time brewing beer however I’ve been fermenting mead for over 10 years, never had this happen. I guess time will tell if yeast becomes active again.