BeerBorg

For my last couple of batches I had bee n stirring every 10-15 mins , with my temp going down way too fast even while wrapped with a sleeping bag.

Is stirring this ofen over-kill? Would stirring twice for 75 min mash yield good efficiency results (70%)?
How often do you guys stir the mash?

For BIAB I did that often, since my pot maintained temp being inside the oven. With a traditional mash tun, I only stir once at the beginning of the mash to get the water and grains mixed in well, then let it sit. I've been getting 68-70% efficiency w/ my mash tun, but it's still a new technique to me. BIAB, I was getting 75-85% regularly.

For my BIAB's I stir every 15 minutes and if there's a mashout, I stir just about the whole 10 minutes. I believe it does help release the sugars a bit. I almost always hit my OG and mostly a bit higher.
But still can't quite hit my FG's as I would like though I don't think the stirring has anything to do with that.

Sparging, rinsing of the grain, is also very important in hitting efficiency. When I sparge, I stir often to make sure the sugars are suspended in the water.
Make sure you are mashing long enough for the temp and mash thickness.

I mash in a 10 gallon round cooler. I stir once at the beginning real good, then once at the half way point of the mash. That's it. I've done it every 15 minutes like you and also noticed too large of a temp drop so I stopped. I have been getting appx 65% efficiency either way, so I don't think it's all that necessary to stir every 15. Based on yesterday's brew results, I've come to the conclusion that the sparge method may be the most important aspect of getting good efficiencies.

As other have stated, I stir once at the start of the mash in my mashtun then let it rest for 75 mins. I then sparge twice until I get my boil volume.

With BIAB I use the oven method and can stir a couple of time during the mash. I don't do a mashout and also sparge.

Efficiency both methods is anywhere from 68-75%

I stir every 20 min.,But , I mash for 90 min and hit my numbers and efficiency went up to 75 - 80%

Also , I use Phil's modified sparge method.

J, are you talking about my BIAB sparge? Drain, squeeze, rinse, squeeze?

I too mash for 1 hour. Stir good at dough in, and then stir good at halfway, and then after I add the sparge water as well

No stirring at all after 'dough in' here. Used to, but all it does is lose heat when you stir.

I stir once to get the dough balls out. Then put the lid on and leave it on. No need to stir after that. It only gives up heat. I do the same for my batch sparge.

10-4 Phil.