Heat Loss

[C-Rider]

Ok, I do small batches like 2 gallons. My mashing volumne is usually around 2.8 gallons w/say 4.5 lbs of grain.

I mash in a Colman 5 gallon round cooler. I preheat the cooler to about 130* for like 20 min before putting in the strike water and then the grain.

I find that I lose about 8 degrees just adding the grain and another 8 after an hour mashing. I open the cooler and mix about every 20 min.

I have not tried adding more insulation around the cooler. Would that help? How about preheating w/hotter water say 150*????

My beers come out fine but I keep wondering what they would be like if I could hold the mash temp constant for an hour.

 

[McKnuckle]

I brew a similar batch size and also (sometimes) use a 5 gallon round cooler. Obviously the most important thing is to adjust your strike water temperature so that mash-in is at the right spot. I assume you're doing that?

Here's a calculator for it.


The temperature loss during mash is another thing. I lose a few degrees, too. Placing a simple piece of tin foil over the top of the mash helps a little. Tossing a blanket over it would help too. Pre-heating with water at least as hot as the mash will be should be useful.

I have tended to not worry about it, but it's starting to bug me as well. I am experimenting with mashing in an insulated aluminum kettle with electric heat control.

 

[TexasWine]

Ok, I do small batches like 2 gallons. My mashing volumne is usually around 2.8 gallons w/say 4.5 lbs of grain.

I mash in a Colman 5 gallon round cooler. I preheat the cooler to about 130* for like 20 min before putting in the strike water and then the grain.

I find that I lose about 8 degrees just adding the grain and another 8 after an hour mashing. I open the cooler and mix about every 20 min.

I have not tried adding more insulation around the cooler. Would that help? How about preheating w/hotter water say 150*????

My beers come out fine but I keep wondering what they would be like if I could hold the mash temp constant for an hour.

A suggestion. If you're doing small batch BIAB, don't mash in a cooler. Mash in your kettle and just put it in a preheated oven. If it has a warm setting then set the temp at 150F. If it doesn't have a warm setting, then the min temp allowed is probably 170F. Preheat to 170F, mash in (make sure to stir like madman), turn off the oven and put your kettle in it, uninsulated of course. When I do this it doesn't loose a single degree.

Or you could just shorten your mash time like a lot of us have done.

Personally, I don't think it's a necessity to stir during the mash. As brewers we oftentimes feel like doing nothing is somehow wrong.

 

[Peruvian802]

^^^i did this last week for a 3 gallon batch. I removed some racks and my oven fit a 22 qt kettle just fine. I set the oven to 165 and it held my 150 mash temp perfectly.

 

[RM-MN]

Ok, I do small batches like 2 gallons. My mashing volumne is usually around 2.8 gallons w/say 4.5 lbs of grain.

I mash in a Colman 5 gallon round cooler. I preheat the cooler to about 130* for like 20 min before putting in the strike water and then the grain.

I find that I lose about 8 degrees just adding the grain and another 8 after an hour mashing. I open the cooler and mix about every 20 min.

I have not tried adding more insulation around the cooler. Would that help? How about preheating w/hotter water say 150*????

My beers come out fine but I keep wondering what they would be like if I could hold the mash temp constant for an hour.

Try heating the cooler to 160 or 170 since that is the range of your strike water. You should lose some heat when you add grains, that's why you have a strike temp that is above the mash temp. The cooler grains will pull down the water temp from stike to mash.

The warmest part of the cooler is the top so when you open it to stir the mash you are letting the hotter air out and replacing it with cool. Of course you then lose a couple degrees. If you mixed in the grains like you should at the beginning they don'r need any more stirring.

You also should stop worrying about losing the few degrees over the course of the hour because if your grains are milled like they should be the conversion was done well before an hour. After that the grains just sit in the hot water like you would in a hot tub, just relaxing.

 

[TheHappyHopper]

Ok, I do small batches like 2 gallons. My mashing volumne is usually around 2.8 gallons w/say 4.5 lbs of grain.

I mash in a Colman 5 gallon round cooler. I preheat the cooler to about 130* for like 20 min before putting in the strike water and then the grain.

Preheating your cooler to a higher temperature is probably the way to go. However, for that size batch it sounds like your cooler is much larger than it needs to be, so it is soaking up a lot of that heat. I have a small mash tun that I made from a 2-gallon cooler that I use for my 2-gallon all-grain batches (and 5 gallon partial mash batches) and it does a good job at holding the temperature. We both would have about the same amount of thermal mass, but my cooler has a smaller surface area to dissipate heat.

You could also consider doing 30 minute mashes - many people have had success with that.

 

[C-Rider]

Just ordered a 3 gallon cooler from Amazon. Hope it will take all my water + grain. LOL

 

[Gavin C]

Try heating the cooler to 160 or 170 since that is the range of your strike water. You should lose some heat when you add grains, that's why you have a strike temp that is above the mash temp. The cooler grains will pull down the water temp from stike to mash.

The warmest part of the cooler is the top so when you open it to stir the mash you are letting the hotter air out and replacing it with cool. Of course you then lose a couple degrees. If you mixed in the grains like you should at the beginning they don'r need any more stirring.

You also should stop worrying about losing the few degrees over the course of the hour because if your grains are milled like they should be the conversion was done well before an hour. After that the grains just sit in the hot water like you would in a hot tub, just relaxing.

I can't shake the vision of "relaxing" as a bloody pulpy fragmented mess in a hot tub after being fed through a grain mill by someone. . Nice analogy all the same.

 

[C-Rider]

I can't shake the vision of "relaxing" as a bloody pulpy fragmented mess in a hot tub after being fed through a grain mill by someone. . Nice analogy all the same.

Your link is not working.

 

[Gavin C]

Your link is not working.

Thanks for the head-up C-rider

Should be working now. Just fixed it.