Hoping for some suggestions. Recently switched from round igloo coolers to a keggel set up for my mash tun. In the cooler I was getting upper 70's to low 80's for my efficiency. Ever since the switch, 5th batch was last night, I've dropped to mid to high 60's. Thoughts? I'm going to double check the thermometer accuracy this weekend, maybe I hit the probe stirring and now it's off? Draining the tun to fast?