No temp loss...I don't believe you...

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
tireater

tireater

Well-Known Member
Joined
Feb 25, 2009
Messages
378
Reaction score
0
Location
Santa Barbara
I keep hearing people say they have a 1 deg temp loss in a 5 gal MLT over an hour...
I no longer believe this can be true....If you open it for any reason...
 
Simple answer: don't open it. :)

In all seriousness, once you've stirred well and hit your mash temp, there's no reason to open the MLT until the end of the 60 minute rest.

The thermal mass of the grainbed is large enough to keep the temps very stable.
 
I use a 10 gal. MLT and lose < 1* for a 60 min. mash. And I DON'T open the lid. There is no reason to.
 
Yeah I use a 5 gallon cooler that claims to "Keep ice for 5 days at 90 degrees." I sometimes open the lid in the last 10 mins to give it a good stir but usually leave it closed and loose less than 1 degree.

Depends on your cooler etc, a thin cheap one wont work as well as a thick one.
 
I just did a batch yesterday and only lost 1* during a 75 min mash using a 10-gal igloo ice cube. I think I saw that you were using the 5-gal version - do you keep blankets/towels on the top to minimize heat loss?
 
I must have cheap coolers...the temp drops like the stock market...
I hit it with steam every 5 min to keep it stable...
Maybe my sight tubes kill it? Even though I preheat the coolers...
Both coolers drop pretty fast...1 deg in 5 min...
 
GunnerMan said:
Yeah I use a 5 gallon cooler that claims to "Keep ice for 5 days at 90 degrees." I sometimes open the lid in the last 10 mins to give it a good stir but usually leave it closed and loose less than 1 degree.

Depends on your cooler etc, a thin cheap one wont work as well as a thick one.
Click to expand...

+1, I do the same exact thing.
 
I use a 10 gallon round (Gott style) Rubbermaid cooler. Even on small batches (under 8 pounds of grain), I don't lose any temperature. I preheat the cooler with very hot water, and then wait until it lowers to my strike temp. Sometimes I open and stir, sometimes I don't. Most often, I don't. There are times, though, that I just can't seem to leave it alone.
 
Also have a 10 gallon Rubbermaid round cooler and did a 147 degree mash yesterday and lost less than 1 degree over 90 minutes.
 
do any of you see a hike up in brewhouse efficiency when you stir? Im debating stirring half way through the mash to keep stratification to a minimum and possibly sweeze out a few extra percentage points
 
tireater said:
I get 87% stirring often....Should I see what I get w/o stirring? I'm a noob....
Click to expand...

Get your strike water to where it needs to be (usually around ~168 or so, but learn to use that BeerSmith that your ADHD wont let you learn for the strike water to grain temp calculation). Then dough in, stir so you don't have any doughy balls (yes I said doughy balls). Watch your temps, shut your cooler lid and just let it go for the 60 minutes. If you keep opening in the lid you'll keep losing the temp. I use one of those probes connected to a wire type thermometers, so I can close the lid and the lid safely closes over the wire and I can watch the temp. I was able to stay between 153-154 for 90 minutes on a pre heated 70qt cooler with ~13lbs of grain and 4.25 gallons of water.
 
summertime is coming up for us zonies, we have to throw in a couple of ice cubes to keep the cooler from melting into the ground :)
 
I stir with a double wheel paint stirrer with the lid closed...
and I can still see the temp go down on the dial thermometer...
Any of you experts getting 87% effiency?
 
FWIW Tireater... I use the 10 gallon Rubbermaild coolers and I always lost about 3F or so during a 60 minute mash, mine never held the temps as well as apparently everyone elses do.

Of course the HERMS fixed that problem, but I never had the "zero loss" experience that everyone else has.
 
Lil' Sparky said:
You're not trying to say all of those HERMS/RIMS systems aren't worth it, are you?
Click to expand...
Nah, it's a serious question. I've seen other threads like this and also seen people mention 'no temp drop' with a sense of pride (or whatever) so it seems some folks are very conscious about it and I was just curious why. I mash in a SS pot so I obv don't have as stable a temp as a cooler...but I never thought it to be a problem.
 
Yeah, I don't think it's a huge deal for a homebrewer, either. I've brewed some damn good beer with my sanke MLT, that clearly doesn't have zero temp loss.
 
SpanishCastleAle said:
Nah, it's a serious question. I've seen other threads like this and also seen people mention 'no temp drop' with a sense of pride (or whatever) so it seems some folks are very conscious about it and I was just curious why. I mash in a SS pot so I obv don't have as stable a temp as a cooler...but I never thought it to be a problem.
Click to expand...

I guess a couple of degrees really don't matter- but 5 degrees would, especially if it drops near the beginning of the mash. It's not so much a sense of pride, but of knowing how the beer should turn out based on mash thickness and temperature of the mash. My system holds the temperature. I like it because I can easily calculate my mashout temps and sparge temps, since I know the temp of my grainbed without even opening the MLT.

It's the same thing with efficiency. Say I get 75% efficiency each and every time, and make great beer. Why should someone who gets 88% efficiency think that they are "better" than I am with my system? It's just a number that helps us dial in our recipes. It's not better or worse- it's a number. In fact, some authorities have written than a super high efficiency might be detrimental to the flavor profile of the beer (I don't think that would be an issue with homebrewers). It's just a way to talk about our systems (all are a bit differerent) and to compare what works for us.
 
YooperBrew said:
I guess a couple of degrees really don't matter- but 5 degrees would, especially if it drops near the beginning of the mash.
Click to expand...

It seems to me, that this is the key point. If the large majority of conversion is done in the first 10-15 mins, and your temp is where you want it during that time (or within a degree or so), how much difference does it make if it drops a few degrees after that? I doubt much, but then again, I'm not an enzyme expert so I won't be dogmatic about it.

I do understand the desire to have mash temps that don't budge and the pride that would come from building a system that does so.

Anyway, back to the topic at hand. Even with my sanke MLT that does lose a little heat, on warm days, with a big 10 gal batch, it won't lose but 1-2 degrees during the mash (if I don't add any heat back), so I believe those that say their temps don't budge if they use a well insulated cooler. There's no reason that they should.
 
YooperBrew said:
I guess a couple of degrees really don't matter- but 5 degrees would, especially if it drops near the beginning of the mash. It's not so much a sense of pride, but of knowing how the beer should turn out based on mash thickness and temperature of the mash. My system holds the temperature. I like it because I can easily calculate my mashout temps and sparge temps, since I know the temp of my grainbed without even opening the MLT.

It's the same thing with efficiency. Say I get 75% efficiency each and every time, and make great beer. Why should someone who gets 88% efficiency think that they are "better" than I am with my system? It's just a number that helps us dial in our recipes. It's not better or worse- it's a number. In fact, some authorities have written than a super high efficiency might be detrimental to the flavor profile of the beer (I don't think that would be an issue with homebrewers). It's just a way to talk about our systems (all are a bit differerent) and to compare what works for us.
Click to expand...
Ah OK, thanks. I guess it's all about being 'in tune' with your process/equipment. I bet if I used a cooler and kept everything else the same my attenuation would change a bit.

I agree on the high efficiency. I had tweeked mine up to ~90% but then decided to scale it back to ~86% plus now I don't even put the last 2 qt. of runnings in the kettle...that now gets reserved/frozen for yeast starters. So my brewhouse eff is now only like 82%-83%. But I think doing that reduces some astringency/harshness and increases the 'yummy factor' (technical term).

Sparky,
I thought that in the case of losing temp; the enzymes still work just like they did at your 'original' rest temp but just a tiny bit slower. And since conversion happens way faster than many of us rest for (like you said, most of it occurs in 15 minutes or so) I didn't consider it a problem at all. But it sounds nice to not have to stir but I still can't see how the mash is not stratified by temp at the end of an hour. I obv have to stir quite often.
 
I just built a MLT and on my first AG brew I was very surprised to note a 1-2 degree drop over the course of the mash, stirring twice. I was expecting several degrees and frankly got a bit nervous about having to add hot water to keep the temp up there.

Preheated the MLT, noted preheat temp and plugged into Beersmith. BM told me what temp I would hit with the grains and water I was using and it was dead on after mixing. Stayed there too.
 
Besides covering a cooler with insulation, something that appears to have helped on my cooler was using a ratchet strap to pull the lid down a bit tighter. I brew outdoors on days that are in the 40's and rarely lose more than 2 degrees.
 
Higher water to grist ratios will hold heat longer too as water has a much higher volumetric heat capacity than grain. Depending on room temp, I loose 1-2 degrees over 60 minutes in my 5gal rubbermaid with a 2 q/lb ratio.

The Rubbermaid tops suck. They're un-insulated and heat rises. If my losses were excessive, I'd consider figuring out how to fill the top with spray foam.
 
I shot a can of spray foam into the lids when I made the mods...I'll try more water today...
I am probably losing heat thru the sight tubes...
 
You should also thinking about minimizing the headspace as much as possible; you are losing heat to the space between the top of the mash and the lid. Easiest fix is float a piece of thick foam insulation right on top of the mash. Bet you don't lose a single degree then.

Also, heat your strike water to around 10 degrees over what your software is telling you and let it drop down to your intended strike temp. i.e if you want to strike at 165, heat to 175 and dump that water into the cooler. When it has dropped down to 165, add your grain and go.
 
I have been doing it the other way...Put the grain in and dump the water from the HLT...Mix with power stir...
 
Using a stainless pot, on a wooden counter top, with towel/tinfoil insulation wrapper, and covered with a towel, I got less than 1 degree of temp loss. Also had almost no head space (literally had to scoop liquid out to fit all my grains :p )
 
I'm with Yooper. HOT water in the 10Gal cooler, let it soak up as much heat as possible. Mash in at strike temp. stir at least 2 times over 60 mins...sometimes more. Cover the lid with an extra towel. If I lose 1 degree, I'm surprised.
 

Similar threads

dhoyt
Glycol Temps, whats yours?
Replies
11
Views
902
Mr. Vern
Mr. Vern
P
Kettle heat loss
Replies
8
Views
622
Porter_Stout
P
Zippy123
Scottish Wee Heavy stuck fermentation or high FG?
Replies
17
Views
943
Zippy123
Zippy123
agentbud
Half-size Batches?
Replies
2
Views
751
Yesfan
Yesfan
Bilbo24
Wort cooldown temps and time????
Replies
17
Views
2K
marc1
marc1
BrewSwag 300

Latest posts

Back
Top