After you pour your strike water on the grains if them temp falls below your target can you bring it up with fired heat or will this give off flavors I have been reading for a while and cant find a straight answer
Fire it up but make sure you are stirring/recirculating so there is no scorching of the grain. I do that every batch to keep the temp in the target range. Sparging as well to keep at mash out temp and I've never had an issue with tannins.