temperature retention question

I've been doing all grain batches with pretty good success for a year or so now using a rectangular converted cooler for a mash tun.. My cooler works pretty good, I will lose about 1-2 degrees over an hour depending on how much grain I'm working with. I see that alot of folks are using kettles with false bottoms,valves,ect.. I was wondering what the glaring advantage is as I would like to upgrade my equipment if it is for the better. What kind of temp. loss do you guys see over an hour period or do you use direct heat under the MLT to maintain temp? Thanks in advance!!


Primary- Ed Worts Robust Porter
bottled- Ed Worts Afpelwein, Scotch Ale

I like to mash in a kettle, then transfer into a cooler lauter tun.

I can then do step mashes and mashout without adding extra liquor. I also found my cooler mash tun is a bit crappy at heat retention, even though I added more insulation.

I use a 15 gallon direct fire SS pot with a false bottom and a valve. I have an insulation blanket that I use in the winter time. It will drop about 1 degree over 2 hours. Keep in mind that the flame is only on during the initial heating of the strike water, not during the entire Mash. I used to use a cooler and to be honest the only reason that I went to a pot was because I wanted to do 10 gallon batches. That and I found it on Craigslist on the cheap.

ETCS said:

I used to use a cooler and to be honest the only reason that I went to a pot was because I wanted to do 10 gallon batches. That and I found it on Craigslist on the cheap.

Click to expand...

Yep, me too. The cooler worked perfectly, but maxed out at 23 pounds of grain.

Thanks for the responses guys and gals!! ChillWill- I'm not understanding what you mean, forgive me... why transfer your wort to a cooler and not the brewkettle? ETCS- you only lose 1 degree or so in fairly warm weather with nothing but the pot and lid? thats pretty awesome... never would have guessed the SS would hold the heat in so well.

wyoast said:

Thanks for the responses guys and gals!! ChillWill- I'm not understanding what you mean, forgive me... why transfer your wort to a cooler and not the brewkettle? ETCS- you only lose 1 degree or so in fairly warm weather with nothing but the pot and lid? thats pretty awesome... never would have guessed the SS would hold the heat in so well.

Click to expand...

It's amazing how well stainless kegs do hold the heat, at least to me. I was expecting to lose a ton of heat, but I preheated the keg (just as I did the cooler) and didn't lose more than a degree or two in an hour. The thing is, you really need to have the keg pretty full to hold the heat in, so even now for smaller grainbills I use the cooler and for bigger grainbills and 10 gallon batches, I use the keg.

So for 5g batches...say 9-13ish lbs of grain, What would you recommend for a size of pot? I found a 10g SS pot with valve and thermometer for $140... that should be big enough to accomidate that amount shouldnt it? and be pretty full.

wyoast said:

So for 5g batches...say 9-13ish lbs of grain, What would you recommend for a size of pot? I found a 10g SS pot with valve and thermometer for $140... that should be big enough to accomidate that amount shouldnt it? and be pretty full.

Click to expand...

If you ever think you'll want to do a ten gallon batch, you'll want something bigger. But for a 5 gallon batch, a 10 gallon pot is fine.

Keep in mind, though, that you can do a 5 gallon batch in a 15 gallon pot also and keep open the possibility for a 10 gallon batch. It's just something to consider!

Good point! thanks for the advise..

Remember too that something like 90% of your conversion happens in the first 30-40 minutes. I don't sweat losing a degree or two over an hour.

wyoast said:

Thanks for the responses guys and gals!! ChillWill- I'm not understanding what you mean, forgive me... why transfer your wort to a cooler and not the brewkettle? ETCS- you only lose 1 degree or so in fairly warm weather with nothing but the pot and lid? thats pretty awesome... never would have guessed the SS would hold the heat in so well.

Click to expand...

I transfer the whole mash to the cooler lauter tun to batch sparge. I only do 2.5 gallon batches. My mash tun is also my kettle. Bit backward I know, but it works for me

I mash in a 15 gallon stainless steel kettle with a bazooka tube and ball valve. I wrap the kettle in Reflectix, which I bought at Lowe's (maybe it was HD but I think they both sell it). It maintains temp very well even when it's really cold outside. If I miss mash temp after doughing in, I can just turn the flame back on and bump the temp back up to where I need it before closing it up and wrapping it. I like that better than having to add hot or cold water to my mash tun to adjust my mash temp.