Any tips for hitting and maintaining your mash temp with small grain bills?

Arrrgh. I have been sruggling for the last hour to not only reach my mash target temp but maintain it. I am brewing a Scottish 60/- and the grain bill is only 6.375 lb. using a 1.25 qt/gal ratio. I am using an icecube 48 qut. cooler.

I have noticed lately that when I mash small amounts in there I have an almost impossible time reaching temp and maintaining. Mostly reaching it.

I was shooting for 155F got about 149F. Tried using a step calculator to determine the amount of hot water to add. I added 1 qut. of boiling water as er the calculator. Mash was then at 147F!

Anyway, I don't want to rehash this batch just figure out what to do for next time. Any thoughts on how to more efficiently mash small grain bills in my cooler?

1. My guess would be to preheat the tun to help in reaching the mash temp.
2. With regards to maintaining temp. I have never tried it but there was a thread here a while ago. The conclusion was to float a top of sorts to help insulate the mash. I will try and find the post in a min.

another option would be to use a smaller mash tun.

try increasing the water grist ratio to 1.5 qt/lb. The additional water will help in maintaining the temp. But I wouldn't worry to much unless the mash temp drops by more then 4F over the time of the mash. Simply dough in a little higher to compensate for that drop.

Kai

Chris_Dog said:

1. My guess would be to preheat the tun to help in reaching the mash temp.
2. With regards to maintaining temp. I have never tried it but there was a thread here a while ago. The conclusion was to float a top of sorts to help insulate the mash. I will try and find the post in a min.

another option would be to use a smaller mash tun.

Click to expand...

Thanks Chis_Dog

I used to preheat my mashtun but I got away from it as I found that just using the right temp strike water worked fine in most "normal mashes". Perhaps I will have to start doing it again for smaller grain bills.

The thought of a smaller tun had occured to me, but I would prefer not to have a second tun. I'd be interested in the floating top idea.

Kaiser said:

try increasing the water grist ratio to 1.5 qt/lb. The additional water will help in maintaining the temp. But I wouldn't worry to much unless the mash temp drops by more then 4F over the time of the mash. Simply dough in a little higher to compensate for that drop.

Kai

Click to expand...

Thanks Kaiser,

I guess I should have stated that getting to the correct temp to begin with is really more of an issue. I will try the higher ratio next time. I ended up with probably that ratio after adding some boiling water in an effort to raise it. I used a step mash calculator to determine the amount of water. It said to add 1 quart of boiling water to rasie it from 149 to 155. Did not work.

I have done 3 low gravity ales lately and had the same problem with each. Could not get the temperature high enough. I used 2 gallons of 180F water to my 6.375 Lb. of grain as per my brewing software. Ended up with 149 instead of 155F

I saw the same thread Chris is talking about, IIRc the floating top was just a 1" piece of Styrofoam, that may or may not have simply been wrapped in Duct tape...or it was covered in something else...or it might have ben left as is...

I have a couple different sized cooler for very sized grainbills, even an unmodified 2 gallon one that I use with a folding steamer and a grain bag for no more than 4 pounds of grain...

Another thing I have that if I'm mashing outside and am worried about heat loss is a goretex lap bag...It's like a sleeping bag, only not as many layers, and it's for if you are sitting watching tv...it's like a blanket, but it looks like a sleeping back, and you can get inside....I put the tun in there while I'm mashing...

But having said that, I bet if you just preheated the cooler ahead...that will be more than enough to counter all the dead airspace you have above the grain...

Six degrees off isn't too bad. Instead of adding more water, drain some off, reheat, then pitch it back in. That way you don't change your water/grain ratio. What was the initial water temp at dough in? What was the temp of the grain to start with? Your calculator is going to have problems if you leave in the default 70 or 80 degrees F. and you just pulled the grain out of the freezer. Been there, done that, T-shirt has holes in it.

No beering for me today . Tiling, ya, way fun. oofdah

I use a 10 gallon MLT and a tyrofoam lid on top. My MLT is a round, rubbermaid cooler, and the foam was from a cooler of Omaha Steaks I got one year for christmas. Its about 2 inches thick, I cut it into the shape of the MLT, and drilled a few holes in it so that I can stick a thermometer into it. It works pretty well. Just float it on top of the grain

I have a second 5 gallon cooler tun I use for small batches now. It doubles as a grant to collect (and measure) my first runnings, so I use it every time I brew either way. It's also perfect for PM batches.

IowaHarry said:

Six degrees off isn't too bad. Instead of adding more water, drain some off, reheat, then pitch it back in. That way you don't change your water/grain ratio. What was the initial water temp at dough in? What was the temp of the grain to start with? Your calculator is going to have problems if you leave in the default 70 or 80 degrees F. and you just pulled the grain out of the freezer. Been there, done that, T-shirt has holes in it.

No beering for me today . Tiling, ya, way fun. oofdah

Click to expand...

Actually that was one thing I tried in my attempt to correct it after two failed water additions. That did bring the temp up (boiling some wort) I just am unsure if any detrimental effects that may have...

Other than that, yes, I set the calculator to the temp of grains. I used 2 gallons of 180F strike water with 6.375 Lb. of grain.

The boiling water might deactivate some enzymes but in a limited area. If you want to see a crazy mash look at decoction (sp?) mashing. It made my head hurt just reading about it. I like to keep things fairly simple but messing with all the gadgets is half the fun. And we know what the other half of the fun is...cheers.