Originally Posted by Skidsmint
I did a 90 minute mash and the temp dropped 7 degrees. I had the pump going for the whole 90 minutes so the drop really isn't that bad.
Next time try this: Instead of using the pump and recirculating, simply do your infusion and then let it set.
I bet that you'll find that the temp doesn't drop more than 2-3 degrees over 90 minutes (instead of 7 degrees).
Consider this: Your pump and hoses actually act like a heat exchanger, pulling 150 degree wort out of the cooler and exposing it to room temperature air, effectivly cooling
it for the complete duration of the mash time. Unless you have a means to add heat to the wort while recirculating (RIMS, etc) you are actually defeating the purpose of the insulated mash tun.
BTDT, got the t-shirt to prove it.