2 gallon cooler PM

2 questions:
1. 1st time using a cooler. I had only used DB's method prior. I used a 2 gallon igloo. 4lbs of grain, 5.5 qts of water there was not a lot of headroom.
I lost like 6.5 degrees over an hour long mash. I imagine most of the heat escaped from the lid as it is not well insulated. Is there anything I can do next time to minimize my temp loss? I am thinking that I may need to get a different cooler with a better insulated top.

2. I heated my sparge water up to 180F. I should have gone for 190F. My temp inside the cooler was only around 160F. I was shooting for an OG of 1.041 but it came out to about 1.040/1.039. Is this because of the low sparge temp or is it a combination of both problems(mash temp loss+ low sparge temp)

Thanks in advance.
Carl

I wouldn't say the cooler lost 6.5 degrees, it's more likely that the cooler TOOK that heat. What temp was the water that you used for your mash? Put that water in way hotter than you think you need. I'd suggest 180F. Close the lid and let it suck all the heat it wants over 5 minutes or so. Open up the lid, stir, measure temp and wait until it's about 167F. If it's still too hot, stir the water until it drops. Then mix in your grain. Close the lid again, wait 5 minutes, stir and check the temp.

What sparge method did you use?

The lid is probably the biggest source of heat loss-- I have a 2 gallon cooler with an uninsulated lid. I made a circular cutout of two layers of foam core and wrapped it in plastic wrap. This fits inside the cooler and rests on a ridge at the top. It definitely helps with the heat loss, but it's not perfect. I'm looking into making a more robust insulating cap.

Also, doing what Bobby suggests definitely helps too. Once I started doing that, hitting my temperatures was a lot easier.

-Steve

Bobby_M said:

I wouldn't say the cooler lost 6.5 degrees, it's more likely that the cooler TOOK that heat. What temp was the water that you used for your mash? Put that water in way hotter than you think you need. I'd suggest 180F. Close the lid and let it suck all the heat it wants over 5 minutes or so. Open up the lid, stir, measure temp and wait until it's about 167F. If it's still too hot, stir the water until it drops. Then mix in your grain. Close the lid again, wait 5 minutes, stir and check the temp.

What sparge method did you use?

Click to expand...

My strike water was 166F as per beersmith. The mash temp was 150F.
I did put the water into the cooler first for a couple of minutes and when I doughed in I actually hit 150.5F. It maintained this temp for probably 10 minutes or so then started to decrease slowly from there.

I batch sparged. Is there a formula to get the grain bed at around 170?
I did some reading after wards and it seems like a lot of people heat the sparge water to about 190F?? I know that high sparge temps will extract unwanted tannins but what does low sparge temp do? Just screw up my efficiency?

Thanks again.
-carl

carl_g said:

My strike water was 166F as per beersmith. The mash temp was 150F.
I did put the water into the cooler first for a couple of minutes and when I doughed in I actually hit 150.5F. It maintained this temp for probably 10 minutes or so then started to decrease slowly from there.

I batch sparged. Is there a formula to get the grain bed at around 170?
I did some reading after wards and it seems like a lot of people heat the sparge water to about 190F?? I know that high sparge temps will extract unwanted tannins but what does low sparge temp do? Just screw up my efficiency?

Thanks again.
-carl

Click to expand...

what bobby was refering to is called pre-heating your mashtun. you probably hit the lower temp in parts of the system but it took that long to equalize throughout the tun.

when batch sparging the 170* rule kinda goes out the window. you want your initial sparge hot enough to raise the grainbed temps to 170 or so wich mean with a 150 temp most of us use 180-190* first sparge water and our second sparge is down around 170-175. the tannin extraction is actually a bigger problem for fly spargers since the sparge is continous and the higher heat tends to strip the ph of the grain bed out and the lower ph is when the tannins start leaching out of the grain husks.

conventional theory says that higher sparge temps will extract more sugars since they make the liquid less viscous and easier to drain than a cooler sparge will. kaiser has done experiments that tend to contradict these notions but i also believe he was doing full fly sparging during them.

Ok, thanks for the information. I will preheat the cooler longer next time and set my sparge water temp for 190F and see how it goes.
-carl