I’ve seen where some batch sparge brewers will stir their mash one or more times during the 60 - 90 minutes mash, to keep the temperature uniform in their picnic cooler mashtun. Due to temperature loss from opening up and stirring, they have to compensate by adding enough boiling water to get back to the desired mash temperature. I’m just wondering how many of you do this, or just live with the inevitable range of temperatures inside the mashtun due to hot and cold spots.
I’ve always just hit my desired mash-in temp, closed the rectangular cooler lid, and left it alone until the mash is over. As I brew outside, if it is cold outside I throw a couple blankets over the cooler to prevent additional heat loss.
I believe that I receive the general desired effects from the mash temp I’ve selected, but I have nothing to compare this to. My range of temps at the end of the mash due to hot and cool pockets inside the mashtun varies, but can vary by as much as about 3.5 degrees, but normally just 2 to 3 degrees.
I do as you do. I do add a bit of rice hulls to my mash it seems to allow for a more even temperature throughout the grain bed when checked it varies by only 1 degree instead of 2 or 3 like I had before
Interesting. I might have to try that. I have two coolers, both Rubbermaids,a 60-qt and a 75-qt. Offhand as I recall, I get less variation in the the thicker walled one (75 qt), which is a 5-day cooler.
There is zero advantage to stirring after the first 5 minutes. If you crush enough and sparge with the right volumes, you can hit 90% mash efficiency just by mixing 'er up at the beginning, and shutting the lid for 40+ minutes. That’s another thing… anything longer than 45 minutes is pretty much a waste of time. You only gain 1-2 efficiency points beyond that mark.
I don’t stir. I don’t use rice hulls. I don’t open my cooler once the mash has begun. I lose maybe 1-2F over a 60-90 min. mash. If you mash in a cooler, it really shouldn’t be necessary.
I don’t stir either. I use rice hulls because it helps with the lauter on most of my beers, but I’m using a Brutus 10 type single tier system with a fly sparge. If using my cooler mash tun I don’t need to use rice hulls and I don’t stir…and I usually lose a degree or two.
Thanks guys for your insights. I learned the batch sparge method from Denny’s site back early in 2005, and have very happily stuck with it (with a few equipment modifications), and see that you all likewise have little or no concerns about a few hot or cold pockets in the MT.
At no time did the idea to open and stir sound desireable to me, for all the reasons you captured well. But I have encountered quite a few examples of people who promote it.
I only brew 3 gallon batches, so I have even less thermal buffering capacity than most other brewers. I typically lose 2-3 degrees over the course of a 75-minute mash. I tried stirring mid-mash on a couple of occasions, and ended up losing 6-7 degrees. I stopped stirring after that