Is it possible to keep mash temps consistent for hours with a 10gal cooler mash tun? I`m looking at the Tropic Thunder APA in the recipe forum, and can`t imaging my cooler would maintain 150 for 10hours as suggested.
I don't think there's a cooler that will maintain a mash temp for 10 hours. But I doubt that it's necessary.
I believe that @jbakajust1 puts that time in there because he regularly does overnight mashes. It is not necessary to do an overnight mash, that it just his preference based on his timing/schedule. I would assume you will be fine doing a normal 60 minute mash.
As @VikeMan alluded to, I don't actually maintain that temp for 10 hours. I do overnight mash (@scurvy311 is referencing my thread here). It drops to around the high 130*s over that 10 hours. As @OddNotion stated, I wrap my MLT in a heating blanket and old sleeping bag for the overnighter. I do it for the convenience of having my Saturday to myself (Friday night mash after boys go to bed, then ready to go with a sparge in the morning and boil). If attempting that beer (or any of my beers that reference long mashing times) do a standard 60 minute and adjust the Mash Efficiency to your parameters, then adjust the grain bill to those parameters to get the same % and OG as you would with any other recipe. That beer is really enjoyable too. Good luck.
If you are going to mash "normally" consider dropping your mash temp a few degrees... A wort @ 150 dropping to 130 over 10 hours will be more fermentable than a wort at 150 for 1 hour!
I did it originally to break up my brew day. I now do it for beers that I want to finish very dry. I brewed a 1.055 Cream Ale a few years ago that finished at 1.003 using US-05. It was damn near flavorless (I loved it!). It's also an excellent technique for Imperial styles if you're looking for a lighter body. I suppose you could do much the same using table sugar, but this seems, somehow, more 'correct'. FWIW, my cylindrical Rubbermaid cooler typically loses about 6 degrees over nine hours. I lay pot holders on the otherwise uninsulated lid.
That's not been an issue in the handful of times I've done it. It's consistent (predictable) enough to have earned a permanent spot in my bag of tricks.
Just used it again on Friday/Saturday. Dropped about 12*F over 10 hours of mashing. I have done super dry beers, and big chewy ones (mashed at 160*F for a Wee Heavy). It breaks up the brew day. No way I was hitting the garage at 8am and leaving it at noon producing 4 fermenters containing 3 beers from 2 boils off of 1 mash for a roughly 1.044 wort from 20# of grain using a typical 1 hour mash. Had the whole rest of the day to spend with family.
Nope. Never had any harsh flavors, no tannins, no off flavors, no sourness. Makes great award winning beers.
Do you have any idea how steep the temperature dropoff is when it starts to fall? Like would you say there's no noticeable dip in temp for the first, 4 hours? Or would you say you consistently lose a degree every hour? I don't expect you've measured, but if you have, I'd love to hear how it measured out!
I don't have numbers (and I'm not the one you asked), but thermodynamics pretty much dictate that the temperature drops per time period (after accounting for the heat being produced by the mash itself) will be bigger early on than they will later.
@toastw I would default to @VikeMan as he knows more about brewing (and sciency stuffs) than me and I have never done any experiments or measurements. Every time you get in there to check you would be releasing the heat in the form of steam from the head space thus impacting the temp drop over time. I guess I could put a digital probe thermometer in there, but the temp drops more towards the exterior of the rectangular MLT than the interior, and even more-so close to the metal ball-valve and pick-up tube so readings would have to be performed at various locations in the MLT at once.
