Do what you enjoy and makes beer you like. It’s a great hobby, don’t get so bogged down in details that you forget to enjoy it!
Oh sure, blame the inanimate object ;). I learned a very long time ago to never place total trust in anything that has moving parts, which includes thermometers. I typically use a floating thermo and a lab thermo rubber banded together with the sensing bulbs parallel [and some of you thought you were anal]. The two meters register about a degree and a half different so I split the difference. I also do stir more than I should if HSA is taken into consideration. My point is that I suspect what takes place in my mash tun is pretty typical of what takes place in almost everyone else’s mash tun, and that is that we’re not achieving the degree of temperature control that we’d like to believe we are getting, and yet for most brewers the beer turns out quite drinkable, at the very least. If you can dial your mash temp in to within 1/2 a degree without busting a gut, cool. If not, don’t sweat the petty stuff.
And FWIW, my brew day is never less than 6 hours and batch sparging hasn’t significantly shortened it, but it has improved yields and is a lot less dickin’ around than fly sparging.
I’m definitely not ever convinced that my thermometer reads exactly accurately (though Thermowerks makes nice products). But it reads accurately and consistently enough to help me make good beer. It’s just that when I read that you’re reading “10 or 15 degrees difference in areas only a few inches apart, although usually it’s closer to 5 or so degrees”, it generally makes me think it’s one of two things: 1/ Mash not stirred thoroughly enough, which seems to not be the case here, or 2/ Thermometer inaccuracy. I meant no offense by it whatsoever, but I’ve brewed for over two decades and am able to reach a mash temp within a degree F in maybe 5 minutes of gentle stirring each time. I was just puzzled.
No offense was taken [at least not by me, the inanimate object I’m sure has no feelings to hurt]. I do stir pretty thoroughly but not continuously. I always can find spots with a temperature several degrees higher or lower than the bulk of the mash, as I said usually not more than 5 degrees but occasionally as much as 10 or 15 degrees. It probably isn’t an ideal situation, but I don’t freak out about it. I may be more anal than most about sampling temps in a number of spots, that could partially explain my different experience.
Go with a batch sparge using a water/grist ratio of about 1.75 to 2 qts/lb, stir the heck out of it, and recirculate a little bit (even manually using a pitcher or something like that) after stirring to help set up your grain bed and flush out some of the particulate from in your line. Your mash temp will be very uniform after that.
I can’t speak for anyone else, but I take temperature readings in multiple areas of the mash tun. If the difference in temp is more than 1 degree, I continue gently stirring until it isn’t.
Ya know, it just doesn’t matter all that much. I can pretty much assure you that most commercial breweries aren’t any more accurate than that.
But the recirc methods are, like PICO Brew, right? That’s what I keep telling my wife why I need to buy the Z!!!
Even a recirc system will vary a bit…it just doesn’t matter!