In the recent Zymurgy there is an article that recommends not stirring your mash because it introduces oxygen and other precursors that effect beer quality.
I have always read that of course you have to stir at dough in to mix the grain with water but also stir at 15 mins to equalize the mash temp. I have always stirred at mash out as well to make sure everything is mixed well.
I recently saw an infusion mash tutorial that recommended stirring every 15 minutes to ‘eliminate hotspots’ and it puzzled me. I stir enough to equilize the temperature (and take temperatures at different locations in the mash to make sure) and then seal it up until the next temp change. There is no way an infusion mash is going to spontaneously generate hotspots! Of course, this is not true with a direct fire mash tun. I also think that if the temperature isn’t even when your done with dough-in, stir more then, don’t wait 15 minutes. You’d just be letting different enzymes do work in different parts of the mash, and that’s not what you want.
I used to stir every 15 minutes or so. For the last year+ just at dough-in and mash-out. No problemo.
I’ve tried both stirring and not stirring. The only thing stirring did was let heat escape.
For a few batches I tried stirring halfway through the mash and thought I saw a small increase in efficiency. Now, I usually forget to do it and I don’t see any decrease in my efficiency. I take that to mean, something else helped me get more sugars (someday I’ll figure out what). At this point I stir at dough in and at mash out.
Paul
Agreed. I used to be a stirrer, and my mashes would drop 5 degrees over a half hour. Now I only stir at dough-in and they drop maybe 1* at the very end of the 30min.
This was my first thought. It’s just gonna make your mash temp fall even faster. I stir at dough-in and when I sparge.
It will help your efficiency just a bit, but at some heat loss, if you’re batch sparing. Just remember, stir, not wisk.
It may help your efficiency, but it didn’t help mine at all. Maybe I was stirring in the wrong direction…
Quite possibly. Although we’ve had this discussion before, I still stand on the fact that if the big boys do it, there has to be some merit to it.
What Denny said.
While I’m firmly of the opinion that just because the big boys do it is no reason for homebrewers to necessarily do it. Different systems, different methods.
In the northern hemisphere, stir clockwise; southern hemisphere, counterclockwise. ;)
I only stir at dough-in and mash-out. Like others have said, I just lose heat stirring any more than that.
Yeah, probably not to much to be learned from them. 
That’s not what I said. I said that what they do doesn’t necessarily apply to what we do.
Please note smiley face.
I stir at mash in… whatever the draw backs are, the lumps in there certainly can’t be good.
I thought you stirred up to raise your efficiency and stir down to lower it. 8)
When you’re mixing 3 tons of grain with 2000 gallons of water on a 100 bbl system, I think a constantly running mash rake would be really beneficial to make sure it is all well mixed and to break up any dough balls. Is that not what you’re doing Denny? 
Sure they have to have it to mash in, but why do they keep it going throughout the mash?