I did a AG on Sunday. 23L of Cornish pale. Hit my expected OG of 1048 and Pitched dry Safale 04 at 22’C then straight into the FF at 19’C. By Wednesday all activity had stopped so I took a GR and already hit 1012, increased temp to 22’c, checked again Thursday and this morning,, 1012 !. How is it possible for fermentation to have only taken 4 days, tastes and look fine .