Mash temperature

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Toecutter

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hi all,

I'm kind of new to this, learning as I go. I am using a 50 qt Coleman rectangular cooler to mash. problem I'm having is getting the right temps during mash. I have been bringing the water to 170 dg in the kettle. add about a gallon to the cooler to preheat. when kettle water drops to 164, I add the grain to the cooler, and add the rest of the water. But i'm getting a temp drop in the cooler to 148-149 dg. I'm using a digital thermometer, and i think its off a couple of degrees. will I have problems with conversion at these temps ??

thanks for any advice
 

devilishprune

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No, there will be conversion; however, you should mash longer if your temperature is getting that low because the conversion will take longer. You will also end up with a thinner beer.

Are you losing temperature during the course of your mash? Or are you losing it when you add the grain? I just add the entirety of the 170 degree water to the cooler and let the entire volume preheat the mash tun. Then when that gets to a couple degrees above strike temperature I mash in, because mixing is going to cause you to lose a few degrees.

To keep your temperatures more constant, don't open the cooler to take the temperature throughout the mash. I used to do that as well as to stir it, but now I just shake the cooler around.

Also, calibrate your thermometer. Measure the temperature of boiling water, which should be 212 F. Also, fill a cup with some ice and pour cold water in it and be sure to mix it well. If the temperature of both of these is off by the same amount in the same direction, then you have found your systematic error that you can correct for in the future.
 

JBrady

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I always heat my water to 170, pre heat the tun, add the grain immediately and then adjust down with small additions of cold water until i reach my target temp. So far its been the only way that I can be 100 percent accurate on my brew days.
 

jasonsbeer

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hi all,

I'm kind of new to this, learning as I go. I am using a 50 qt Coleman rectangular cooler to mash. problem I'm having is getting the right temps during mash. I have been bringing the water to 170 dg in the kettle. add about a gallon to the cooler to preheat. when kettle water drops to 164, I add the grain to the cooler, and add the rest of the water. But i'm getting a temp drop in the cooler to 148-149 dg. I'm using a digital thermometer, and i think its off a couple of degrees. will I have problems with conversion at these temps ??

thanks for any advice
It sounds like you still need to dial in your temps a little. Do you think your thermometer is reading too low or too high? Lower mash temps may result in a dryer tasting beer, but should be OK. There are posts here about calibrating thermometers by boiling distilled water (you must adjust for the barometric pressure) on the high end and using a distilled water slushy for the low end. My analog thermometer reads 3 degrees to low and my digital reads 5 degrees too low. My beers were all too sweet and gaining this knowledge helped considerably.

I have a 70 qt coleman. I allow for a 5 degree loss due to the thermal mass of the cooler. I have to calculate the heat loss due to grain every brew day. This takes the mass and temperature of the grain into account to determine the strike temp. See Palmer for more info. Otherwise, brewing software and websites are around that can help you with that.
 

OHIOSTEVE

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I always heat water to 170-175 and put my full mash amount in the cooler. I stir until I reach my desired strike water temp then add my grains. works pretty well.I usually end up a shade higher than desired and stir until I am very close then cover it up and wait.
 

malkore

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1 gallon of water in the cooler isn't enough to really heat it up. that's like...2" of water in the bottom?

I use the hottest tap water I can get, which is about 124F in my house and I'll use 3 gallons in my 5 gallon rubbermaid. Its not a waste though because I eventually use it in my cleanup process by dumping it into another old bucket. Not quite as cool as big brewery's reuse their waste water, but at least i'm not just tossing it.

get a calibrated thermometer too...you can't really do all grain the 'right way' unless you really know what temperatures you're hitting. Granted it'll all be beer, but if you want to enter competitions you'll need to dial your gear in.
 
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Toecutter

Toecutter

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No, there will be conversion; however, you should mash longer if your temperature is getting that low because the conversion will take longer. You will also end up with a thinner beer.

Are you losing temperature during the course of your mash? Or are you losing it when you add the grain? I just add the entirety of the 170 degree water to the cooler and let the entire volume preheat the mash tun. Then when that gets to a couple degrees above strike temperature I mash in, because mixing is going to cause you to lose a few degrees.

To keep your temperatures more constant, don't open the cooler to take the temperature throughout the mash. I used to do that as well as to stir it, but now I just shake the cooler around.

Also, calibrate your thermometer. Measure the temperature of boiling water, which should be 212 F. Also, fill a cup with some ice and pour cold water in it and be sure to mix it well. If the temperature of both of these is off by the same amount in the same direction, then you have found your systematic error that you can correct for in the future.
thanks for the help. It happens after the strike. I just finished the 1st runnings and it looks pretty good. definitly going to be a heavy beer. i'm sparging (soaking)for 15 minutes, sparged at 166 dg, and it dropped to 150 in the tun . I think i will just have to start with a higher strike temp in the future, now that i see what the temp drop is.
 
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Toecutter

Toecutter

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alright, so I finished a few hours ago and its in the brew bucket. i used 11 lbs of grain and 4 oz hops for a 6 gallon batch, and the SG measured out at 1.046 at nominal temp, so i think I'm ok

Btw- got to use the 3/8 30' copper wort chiller i just made. it worked like a dream. was at 81 dg in less than 15 minutes
 
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