[gmac]

I am using a coleman Extreme cooler, 50 quart I believe and I've got a couple questions on how you guys prep these on brew day.
I have seen posts that say they don't lose a degree in the hour you are mashing but today and last time, I left the thermometer in and both times, the final temp was about 10 degrees below the start temp.  For example, today it started at 154 and an hour later the thermometer is reading about 144.  I'm guessing I'm losing a lot of heat to warm the cooler so I'm wondering what you do.  My brews have been thinner than I've wanted and I wonder if this is part of the problem.

All I've been doing is adding a couple quarts of 180 water and sloshing it around a bit and letting it sit for 5 minutes and dumping it. 
Suggestions?
Thanks

[bluesman]

Check out Denny's website and let us know if you have any other questions from there.

http://hbd.org/cascade/dennybrew/

[JKL]

Wow! 10 deg seems like an awful lot in an hour.  How cold is it where you're at?  I put a pillow on the lid of my round Igloo.  You might want to consider that as well as wrapping it with a blanket or Sleeping bag for extra insulation.
-J.K.L.

[theDarkSide]

I usually boil a quart or two of water and dump it in.  I then drain it out the spigot before I start my mash.

Make sure your mash is well stirred up and the temp has had a chance to stabilize.  Is you thermometer a probe type that your can watch from outside or a glass one that you check at the end?

On really cold days, I cover with a thick beach blanket to help insulate.

[a10t2]

For example, today it started at 154 and an hour later the thermometer is reading about 144.  I'm guessing I'm losing a lot of heat to warm the cooler so I'm wondering what you do.

Just add 10 degrees to your strike temperature next time - so in this case, calculate the infusion for a 164°F rest. The exact amount lost to the cooler will change with the mash volume and liquor:grist ratio, but that will definitely get you within a couple degrees.

If you want to get fancy, you can estimate the specific heat capacity of the cooler and - in my experience - hit the mash temperature right on target every time.

[Hokerer]

It sounds like your biggest problem is preheating your cooler.  What I do is to just add my strike water 10 or so degrees higher than the calculated strike temp.  That hotter water will preheat to the cooler and I just wait until the water temp drops enough to be equal to the strike temp and that's when I add the grist.

Doing it that way, with my Xtreme, I don't lose any more than 1 degree during the course of a 60 minute mash.

[tonyp]

Isn't there an issue with BPA-leaching by putting high-temp or boiling water into a plastic container? Are there BPA-free coolers available? This is one of the only issues stopping me from using one and going all-grain.

[WDE97]

+1 on the higher strike water temp and putting a pillow/towel on top of your cooler.

Something else to consider is to put a towel or something under your cooler.  Cold concrete/tile floors or a stone countertop have a large heat capacity so you can lose a lot of heat from the bottom, not just the top and sides.  I was losing @4F over an hour on my 10gal rubbermaid cooler, then realized how cold my granite countertop felt (and how warm the spot the cooler water sitting on felt). After putting a folded up bath towel under it, I now lose <2F over an hour.
 

[Bret]

+1 on the higher strike water temp and putting a pillow/towel on top of your cooler.

Something else to consider is to put a towel or something under your cooler.  Cold concrete/tile floors or a stone countertop have a large heat capacity so you can lose a lot of heat from the bottom, not just the top and sides.  I was losing @4F over an hour on my 10gal rubbermaid cooler, then realized how cold my granite countertop felt (and how warm the spot the cooler water sitting on felt). After putting a folded up bath towel under it, I now lose <2F over an hour.
 

Like camping--most of your body heat is lost down into the ground.

[denny]

Isn't there an issue with BPA-leaching by putting high-temp or boiling water into a plastic container? Are there BPA-free coolers available? This is one of the only issues stopping me from using one and going all-grain.

As far as I know, the coolers are HDPE and contain no BPA.  Am I incorrect?

[weithman5]

watch the temperature of your grain prior to dough in.  not that you need to measure it, but if you sometimes have the grain in the house over night and sometimes take it out of the refridgerator just before that can be a 20 plus degree difference and your strike water can lose heat a bit faster than you excpect

[denny]

Also, make sure you stir thoroughly and check the temp in different areas of the cooler to be sure it's consistent.  Often when I hear of people losing a lot of temp it's because the temp wasn't even to start with.

[WDE97]

watch the temperature of your grain prior to dough in.  not that you need to measure it, but if you sometimes have the grain in the house over night and sometimes take it out of the refridgerator just before that can be a 20 plus degree difference and your strike water can lose heat a bit faster than you excpect

Another good point.

Is it Palmer's book that has formula's for calculating temperatures and water quantities for mashing, multi-infusions, etc?  One of the variables is grain temperature before you add it to the mash.  I put these formulas into an Excel spreadsheet and it makes calcuating everything really simple on brew day. 

[tygo]

Isn't there an issue with BPA-leaching by putting high-temp or boiling water into a plastic container? Are there BPA-free coolers available? This is one of the only issues stopping me from using one and going all-grain.

As far as I know, the coolers are HDPE and contain no BPA.  Am I incorrect?

Rubbermaid coolers are BPA free:  http://www.rubbermaid.com/Pages/LearnAboutBPA.aspx#nobpa

I suspect Coleman coolers are as well but I can't seem to find anything definitive.

[denny]

I have a good friend who's a homebrewer and a plastics guy by trade.  He assures me that all the coolers he knows of are HDPE.