Second all-grain....low temps?

I have completed my second all grain batch, and had some mash temp issues with both batches. I am using a 10 gal. round igloo cooler for my mash tun, making 10 gal batches. I seem to be having trouble loosing temperature during the mash. Both batches were around 22 lbs of grain, room temp., using 170 degree strike water. Temp falls to about 146-148 after about 30 min. I keep the lid ON most of the time,  except when stirring 3-4 times. 1st beer was an APA, missed on style, but still very tasty. Second beer is an Oatmeal Stout, just kegged....but seems to be right on the money so far. Please help.

I have a similar setup with a 5 gallon gott cooler... Are you clicking the adjust mash temp for equipment tab? If not this might help.

I am a BIAB brewers so I just turn the heat on for a second to raise the heat. I (WAS) a 3V brewer and here is what I would do. I preheated the mash-tun to a slightly higher temperature and let it set 5 minuets. I would empty the mash-tun of water and put in the grain/water. After it was stirred I would take a old winter jacket put it around the round mash-tun and zip it up! I would leave it alone! Remember that most of the conversion happens in the first 15 minuets so a slight drop means almost nothing anyway!  Good Luck

What was your target temp?
What is Room Temp?
What is the grain to water ratio?

Using rough estimates from your message,

170F strike
22lb grain
10 G in fermenter

Guesses
150 Target mash temp
11 batch size
1.5:1 water to grain ratio
67 F grain temp

Using 170F strike water gives me mash temp of 158 without thermal loss of heating up the cooler.  8F drop would not be unreasonable and a 2-4F drop over 60 minutes with losses due to opening and stirring.

I recommend preheating the mashtun.  I slosh around 170F water for a few minutes then drain it back into the hot liquor tank.

I fill my mashtun with the desired strike water then add my grains.  I stir well, measure the temp (adjust if necessary), close it and do not open it again until the mash time expires and I check the temp once, then close until I am adding my sparge water.

- Joe

I found I lost a lot of heat through the valve.  I got some foam rubber and wrapped it tight around it and then taped it off.  It help a lot.  I also preheat the mash tun, as Jomebrew suggests.  Last, but not least, I have a small pot of boiling water handy just in case I need a few degrees of adjustment after the strike water is added.

Thanks everyone, this is my first time using this forum or ANY forum for that matter. It's nice to get some feedback! I was targeting 154F with these mashes, ambient temp where my grains were stored was about 75F, and I had preheated my mash tun with about 2 gal. of 170F water. My first method was alternating adding the hot water and then the grains until all the grain was added. I attributed the heat loss to that method at first, so then my second method was to add all of the measured hot water to all the grains, stir and cover. I am using a thermometer mounted through the cooler wall. I don't have any liquid leaks, so I don't think I have any heat loss there, but I'm not positive. Thanks everyone for the suggestions, I will put them to use for my next brew day! I am still open to more suggestions also...

Wooha,
        Just another thought. Can you trust your thermometer? I have had a few problems trying to get temperatures stable but my thermometer was the problem. I now carry a few different types of thermometers (digital, glass and metal) just in case. Just use a little ice water and some boiling water to verify accuracy?

I've found that using a cooler as a mash tun can be very challenging to achieve and maintain temps. It makes it difficult to get exactly the beer that you planned. As long as you don't stray too far over or under your target, you should have great beer. Your thermometer might also have been in a cool spot, which can give you a false reading.
My brew partner and I have discussed how automated we want this hobby to get, and decided that if it were easy it wouldn't be as fun.

Wooha said:

I keep the lid ON most of the time,  except when stirring 3-4 times.
Please help.

Click to expand...

You setup is similar to mine.  Recomendation,  Measure temp once, at 10-15 minutes, adjust IF needed.  But DON'T STIR.  This is a major cause of heat loss.

Cooler lids are a weak spot in the insulation.  Try keeping a blanket or some type cover over it when closed.

I also use a disk of pink insulation foam that rests on top of the grains.  This insulates the grain from the colder air above it INSIDE the vessel. 

I agree with stirring it less often.  If you crushed it properly, and stirred it in well, once you get it to your desired mash, you can leave it alone.

The mash will cool a little from your first measured temperature as it heats the air inside the cooler.

Every time you open it the air inside has to be warmed again, removing heat from the mash.

Every stir exposes mash to air, removing heat from it.

I'd say get it a couple degrees above your desired mash temp to compensate for heating the air, put a lid on it, and forget about it until you think conversion is complete.
Do an iodine test to confirm, then go to the next step.

This latest BYO Magazine did an experiment on mash conversion, and one variable was stirred/not stirred.  One tester found he lost 14F by regular stirring. 

More evidence to recommend mix/stir well/seal it up. 

You will lose the temp because you open it and stir it .
First use some of your hot water add it to the cooler for the time it takes your HLT to get to temp then add your grains stir so that you make sure you dont have any clumps once your doughed in close it and leave it stir like once in the middle of the rest  . you should only lose around 1 degree . that should fix it .


and yup just read that byo very nice I did a smoked Saison in 30 was blown away lol then this artical  came out nice +1