How do YOU keep your cooler mash-tun as close to temp as possible?

[hmmmbeer]

I have been brewing for years and have since gone to AG a few years ago but have never been able to hold my mash-tun AT temp. In the pas I have just accounted for the 2-3 degrees that I lose so if I need to hold 153 I'll mash at 156. I am using a cooler as my mash-tun and thought of using a fermentation band(for a bucket) or even plugging in a heater blanket and just wrap it like a baby. That just gave me another idea, heating pad under the cooler should help too... I might try the heating pad and heated blanket this weekend and see how it does. I'll keep you posted on the outcome. BTW, I'm talking about when it gets cold outside(as I brew in my garage that isn't heated).

How do you keep your temp. close?

Thanks for any ideas!

 

[pigroaster]

I use an extreme cooler with heavier walls and I made a blue foam insert that fills the cup holders and a 1 inch blue foam cover insulates the top even more. I preheat my cooler with hot sparge water 20 minutes before show time and pour it out before I add sparge water around 176F. I have brewed at -10 in garage and temperatures held. I also kept grain in house at 68F before I added it! It works for me. I usually hit 154F doing this. If your temperature is dropping, dough in faster and add fresh hot water.!!!

 

[opiate82]

When I first started using mine, my test showed that I was losing less than 1 degree over 60 minute mashes in my cooler mash tun. The one flaw I didn't account for was that I was brewing mostly big beers that came close to maxing out my mash-tun capacity. After ~3-4 tests I stopped checking the temp because I just assumed it was holding just fine.

I was doing a much smaller beer the other day and decided to re-check my temp loss after reading a thread here about headspace in the mash tun. I was shocked at how much temp loss I had over the course of the mash. Probably accounts for the reason my smaller beers haven't had the body characteristic I was going for.

I'm not so worried about insulating the outside as I keep mash tun in the house during the mash. I am going to come up with a way to insulate the headspace in my mash tun for my smaller beers. I have access to very large food-safe plastic bags so I thought about throwing a sleeping bag in one of those and stuffing that inside the tun.

 

[jimyson]

Pre-heat, leave closed after dough in, cover with blanket. I use the Coleman Extreme and always stay within 1 degree within a 60 minute mash.

 

[JohnnyO]

You're losing heat somewhere. What kind of mash tun are you using? How big is it?

I use a 10 gallon rubbermaid cylinder-type cooler. If I'm shooting for 150F mash temp, I heat my strike water to 165-169 depending on the current temp of the cooler in the garage. I hit my temp and put the lid on. I very rarely lose more than 1 degree over an hour.

 

[Brewsncrabs]

I wrap my round Rubbermaid cooler in reflective insulation. I cut two circular pieces to the diameter of the cooler and place on top of the mash before closing lid. Holds to within a degree. In winter, I carry the tun inside for an hour. Also, don't forget to preheat tun.

 

[brewkinger]

I wrap my round Rubbermaid cooler in reflective insulation. I cut two circular pieces to the diameter of the cooler and place on top of the mash before closing lid. Holds to within a degree. In winter, I carry the tun inside for an hour. Also, don't forget to preheat tun.

This^

Piece of REFLECTIX cut to the diameter of the cooler on top of the mash, close it up TIGHT and wrap a wool hunting coat around it and a wool blanket over the top. It stays at mash temps and I have even gained a degree on a couple of occasions in the summer months.:rockin:

 

[hmmmbeer]

I guess I didn't give details on pre-mash.

I keep the grains in the house 1-2 days prior(in the laundry room is the warmest so I put them there). I also keep the cooler in the house for this time too. I then preheat the cooler with hot water for 20 mins prior to show time. I usually only do big grain bills (no less than 27lbs but only up to 32lbs I found out last brew) because I like my beers high on the gravity . I think its time to just buy a new cooler as this one was scored on the freeway LOL. I'd really like to just use the 3 sanke's I have for all my pots (HLT, mash-tun, and brew kettle).

 

[LandoLincoln]

How I keep my temps to within 1/2 of a degree in a 60 minute mash:

I use a cooler. One of those old steel-belted Coleman coolers. Not sure if it is better at keeping temps than a new one.

After doughing in and getting the temps just right I take a piece of aluminum foil and lay that on the top of the sweet wort, covering the entire surface. This will reflect the heat back down towards the mash instead of allowing the heat to attempt to heat the air above. We lost a lot of heat when we didn't use the aluminum foil. Just try this trick once and see if it doesn't really help out. I bet you it will.

Then I take a roll of duct tape and seal up the opening between the lid and the cooler.

Then, if we're brewing outside and it's cold out, I take a sleeping bag and throw that on top.

 

[jrgtr42]

Mine usually stays pretty close. I will pre-heat with hot water, then mash in, make sure my temps are good, and close the lid and leave it. I actually generally mash in inside, then bring it outside to my full boil rig, which I start to heat sparge water with about 15 minutes to go.
I'll bring it out at 15 or 10 minutes left in the mash, so it will settle back down.
When I add the mash out water, I check the temps, and it's been within a degree or 2 each time I've done this.

 

[FuzzeWuzze]

Yea my 10 gallon Rubbermaid holds temperature no problem, when its cold outside now i usually bring it in and just throw a spare heating blanket throw we have on top of it and turn it on high...not really necessary but it makes me feel better.

 

[Orthobrewsky]

I have a kid's sleeping bag from Walmart which fits my 10 gal Rubbermaid great.

 

[brick]

I throw a quart of boiling water into my 10gal Igloo and close the lid about when I begin heating strike water. That preheats it nicely, and even small beers don't lose more than a degree during a 60min mash.

 

[Mikethepoolguy]

Look for any cracks or holes on the inside of your cooler. If there is even a small hole the cooler is shot. Throw it away and get a new one. Cracks on the outside don't matter so much.

 

[JonM]

I preheat my cooler mash tun with tap water, then add strike water that's a couple degrees too high and let it naturally drop to the proper strike temperature.

After I've done my temp and pH checks, I have three circles of 3/4 inch foam (all a tiny bit smaller than the ID of the tun), and I toss those in a crockpot liner bag and put them into the tun, almost in contact with the mash. Any leftover room above the foam circles is filled up with towels for added insulation. Stays rock solid.

Oh, and in the cold weather, I leave the tun in the kitchen until it's time to start the sparge.

 

[kombat]

I bring my cooler indoors and mash in my front entryway during the winter. I also cover the grain bed with a sheet of aluminum foil while mashing. Then when I vorlauf, I poke a bunch of holes in it (with the thermometer probe from my turkey fryer HLT), so I can pour the recirculated wort onto the foil and avoid disrupting the grain bed at the same time it's helping hold heat in.

 

[Jayhem]

Basic cooler, no less than 15 lbs of grain and 5 gallons mash water because I do double batches. In the summer it will hold temp perfectly. In the winter I just bring it inside the house and cover with a blanket during the mash, only loses 1-2 degrees in 60 min.

 

[RichBrewer]

I pre-heat my cooler with very hot water. I then dump that water and add my strike water at about 5 to 10 degrees above my target mash temp. I let the temp drop and the cooler absorb heat until it hits my target, Then I add room temp grains. It takes a little longer but has worked well for me. I think the key is to get the inside of the cooler conditioned to the strike temperature.

 

[Hamaki]

This^

Piece of REFLECTIX cut to the diameter of the cooler on top of the mash, close it up TIGHT and wrap a wool hunting coat around it and a wool blanket over the top. It stays at mash temps and I have even gained a degree on a couple of occasions in the summer months.:rockin:

Not sure if dry humor, mismeasured temps, or brewing on Venus

 

[wilserbrewer]

This^

Piece of REFLECTIX cut to the diameter of the cooler on top of the mash, close it up TIGHT and wrap a wool hunting coat around it and a wool blanket over the top. It stays at mash temps and I have even gained a degree on a couple of occasions in the summer months.:rockin:

You must be wrapping that cooler pretty tight to gain some "energy" heat

I use an Igloo Ice cube 48 qt cooler
http://www.igloo-store.com/product_detail.asp?T1=IGL+ICE+CUBE&trk_src_ss=IGLPAYPCWEBMACSS&kw={keyword}

It is kinda thin and lightweight, and loses a couple / few degrees over an hour mash...I just RDWHWHB and plan on minor losses, just mash a tad high and let it fall

 

[runkelia]

My MT is a Coleman cooler circa 1980, passed down from my dad as he got bigger and better equipment. So the lid latch doesn't work for s%*t anymore, so I put (2) 20 lb dumbbells on the lid. Works like a champ now.

 

[TheZymurgist]

Does it really matter if you lose a degree or two during the mash? Since the majority of conversion is completed early on in the mash, losing even three degrees shouldn't have a significant impact on the final product. If it does, why not just adjust your mash temps to account for the heat loss? Besides, unless you're crossing over the denaturing temperature lines, the enzymes are still going to be working. I don't think most people can tell the difference between a beer mashed at 156 and 154, right?

 

[NickTheGreat]

I always lost a few degrees after adding the grain. Until I decided to do a 2 batch day. Then I noticed that whilst mashing Batch #2, I didn't lose nearly as much heat. I've since preheated with some hot water and have been much happier

 

[Scutrbrau]

I've got a 70 qt. Coleman cooler. When my strike water is around 130º or so I circulate some through the mash tun for about 5 minutes and then keep it closed. My grain is generally around 60º and the ambient temp in the garage where I brew has been 35-40º lately. I lose only 1-2º of temp over the course of an hour.

 

[SuperX]

I use an old down jacket - my home depot 10g cooler holds 1F for 2 hours even when it is below 40F outside.

 

[hmmmbeer]

Does it really matter if you lose a degree or two during the mash? Since the majority of conversion is completed early on in the mash, losing even three degrees shouldn't have a significant impact on the final product. If it does, why not just adjust your mash temps to account for the heat loss? Besides, unless you're crossing over the denaturing temperature lines, the enzymes are still going to be working. I don't think most people can tell the difference between a beer mashed at 156 and 154, right?

Thats the thoughts I've had. I just mash a bit higher and expect a 1-3 loss. It doesn't matter to me, I was simply wondering if there was any cool ideas people did that would better my process, after all, we always want to improve. I have not missed my OG target so I've been pleased.

With that said, I have some reflective insulating bubble wrap (small bubbles)and aluminum tape that I'm going to make a nice 2 piece "outfit" to help. I'll be sure to bring it into the house like last time, just such a beach with a hurt wrist.

Out of curiosity, what is the largest grain bill those of you using the 10gal igloos?

 

[runkelia]

Thats the thoughts I've had. I just mash a bit higher and expect a 1-3 loss. It doesn't matter to me, I was simply wondering if there was any cool ideas people did that would better my process, after all, we always want to improve. I have not missed my OG target so I've been pleased.

With that said, I have some reflective insulating bubble wrap (small bubbles)and aluminum tape that I'm going to make a nice 2 piece "outfit" to help. I'll be sure to bring it into the house like last time, just such a beach with a hurt wrist.

Out of curiosity, what is the largest grain bill those of you using the 10gal igloos?

I have a chart that says max grain bill for 10 gal. cooler @ 1.25 ratio is 24 lbs. Your OG, 80% efficiency 5 gallon batch would be 1.136, 10 gallon 1.068

 

[danorocks17]

i use a coleman xtreme, but I noticed the steam will escape from around the lid, so I just throw an old comforter over it. Keeps temp extemely well.

 

[kombat]

Does no one else use the foil on top of the grain bed trick?

 

[hmmmbeer]

If there is room, I'll try the foil idea in two days.

 

[TheZymurgist]

Thats the thoughts I've had. I just mash a bit higher and expect a 1-3 loss. It doesn't matter to me, I was simply wondering if there was any cool ideas people did that would better my process, after all, we always want to improve. I have not missed my OG target so I've been pleased.

With that said, I have some reflective insulating bubble wrap (small bubbles)and aluminum tape that I'm going to make a nice 2 piece "outfit" to help. I'll be sure to bring it into the house like last time, just such a beach with a hurt wrist.

Out of curiosity, what is the largest grain bill those of you using the 10gal igloos?

I guess my question is whether it's actually an improvement, or whether it's innovation simply for the sake of innovation. Being able to hit your target mash temp is critical for consistency, and keeping close to that temp is important as well, but will anyone be able to tell the difference between a beer that was held at a constant mash temp vs. one that lost a degree or two, or even three?

Personally, I use a 10 gallon round cooler, and have never lost more than three degrees. I'm able to hit my mash temps consistently, and I'm happy with the final product, so I see no need to hold a perfectly constant mash temp. I guess that's just where I'm coming from. I'm certainly not trying to dissuade you, I'm just wondering if it's even worth the extra (albeit small) effort.

 

[oneandahalfshepherds]

I inject steam midway through and my cooler stays right on temp

 

[brewkinger]

You must be wrapping that cooler pretty tight to gain some "energy" heat

Actually, I have two possible theories:
The error theory that I measured temps. incorrectly.

The scientific theory proposed by PhD chemistry professor at Clarkson University:
If you have a cooler that is preheated with water that is hotter than mash temps (180 degrees in my case) then it absorbs heat (we call this pre heating)
Then dough in, bring temps down to 154 and then insulate and wrap the cooler, it is more than possible for the mash to absorb some of the energy stored in the cooler.
I have to take the man at his word, after all he does have the letters after his name.
I was willing to go with the error theory.

 

[MEPNew2Brew]

With a nod to Land o Lincoln for the suggestion, I used tinfoil to address heat loss. I have a 72 quart Xtreme, pre heat, and do not open during mash. Lost less than 1 degree. Before using tinfoil, I was loosing 4 - 5 degrees.

 

[IanJ]

I've had trouble with my 10g Rubbermade from Lowes. The lid isn't insulated, so I was losing a good amount with test 3g batches, which was kind of a let-down. Recently I've been experimenting with all sorts of materials, wrapping it in reflective emergency foil, pillows and blankets, and was able to keep it to a ~3 degree loss for a 75 minute mash indoors during my last 5g brew.

Something's gotta give! Need a better solution for smaller batches at the very least. Not sure if filling the lid with foam is worth the risk.

 

[govner1]

I've had trouble with my 10g Rubbermade from Lowes. The lid isn't insulated, so I was losing a good amount with test 3g batches, which was kind of a let-down. Recently I've been experimenting with all sorts of materials, wrapping it in reflective emergency foil, pillows and blankets, and was able to keep it to a ~3 degree loss for a 75 minute mash indoors during my last 5g brew. Something's gotta give! Need a better solution for smaller batches at the very least. Not sure if filling the lid with foam is worth the risk.

I use a 7 gal Rubbermaid for 3 gal batches. That's all I do. I preheat w/ 120-140 water while my strike water gets to temp. Then I dump it in a bucket for cleanup later. I usually stay within 1-2 degrees of my target temp.

 

[wilserbrewer]

Heat loss will be dependent on the percentage of the volume filled in the cooler...for smaller batches I feel a smaller cooler is better.

Fwiw
Cheers

 

[Esmitee]

Does no one else use the foil on top of the grain bed trick?

Never tried this method yet, Next batch I will. Seems like I'm always fighting the mash temp! I do use an older cooler too. I brew outside and I'm to lazy and the cooler is to heavy to cart UP and indoors. I made this ( reflextive bubble wrap) cooler wrap and sometimes also use a blanket with the wrap.

 

[brewkinger]

If I have room, I use a circular piece of Reflectix insulation that I cut to fit my cooler. Most batches I have the cooler maxed out with 10-12# of grain and 1.3 grist ratio.
I also drilled 1/4" holes in the lid and filled my cooler lid with foam insulation and then epoxied small plastic caps to cover the holes.
I screw the lid on as tight as I can get it.

 

[EmDubeu]

what about those of us who are using a 15.5 gallon sanke as a mash tun? How are you keeping your mash at temp for 60 minutes?