Author Topic: Partial Mash help  (Read 2112 times)

Offline krustybb

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Partial Mash help
« on: December 27, 2011, 08:09:49 AM »
Last night I brewed my first partial mash. I used the method explained in this article http://www.byo.com/component/resource/article/511-countertop-partial-mashing I started the mash at 154 and let it go for 40 minutes. When I opened it up It was down to 140 so I lost to much heat. Would this ruin my efficiency. Ialso had a 5 gallon cooler instead of a 2 gallon cooller like in the article. I used 4 pounds of base grain and 2.25 pounds of specialty. I only got an a pre boil gravity of 1.021. So I got nearly no sugars out at all. I dont really understand. I used 1.5 quarts of water per pound for the mash. My sparge volume was a bit more than that because my temp got to high and I had to add some water to cool it down. Has anyone gotten good efficiency with this model?

Offline duboman

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Re: Partial Mash help
« Reply #1 on: December 27, 2011, 08:44:31 AM »
At a total grain bill of 6.25lbs you are actually close to an all grain recipe instead of a partial mash. That being said and without knowing the specialty grains used I will say your mash temp and duration are not quite right. generally you want your mash temp to be around 155 and mash for 60 minutes or more, again depending on the grains. Because you had temperature issues and adjusted with water making your volumes off it sounds as though you diluted your wort as well. All of the above will affect your og.

Using a 5 gal cooler as a tun with that much grain should not have made much of a difference unless the ambient temperature of the tun was pretty cold. To correct that you can place hot water in the tun prior to the mash to elevate it's ambient temp so you get less heat loss when adding the grains. In addition you need to be sure to stir in the mash to eliminate hot/cold spots during the mash. I will generally stir twice during a 60 minute mash.

In addition, how did you take your pre-boil reading and at what temp was your sample as adjustments need to be made. All in all, since extract was being used these issues could have been made up in increasing your amount of extract to raise your og during the boil.

I am not the most experienced AG brewer but I know if you post your recipe and details of your session a more experienced brewer will be able to give you a lot more detail as tom what may be done to increase your efficiency. Cheers!
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Offline madscientist

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Re: Partial Mash help
« Reply #2 on: December 27, 2011, 08:57:02 AM »
What did you brew and what OG were you shooting for?  Did you hit anywhere near it at the end of the brew day?  I don't usually measure my gravity coming out of the Mash Tun and before I add extract (now I have a refractometer so I am going to actually start).  I've learned that I should be adding at least a pound more of DME or base grain to get my OG up to where I want.  I do consistently come in a few points low at the end of the brew day.  

Did you preheat the mash tun?  (Heat flows from hot to cool) so if it was cold, it's going to draw more heat out of the water.  Also, the grain absorbs some of the temperature.  I guess more empty space in a mash tun could be a factor.  I have a 2 gallon cooler I use for about 3lb of grain, so I'm usually close to the top of the cooler with all the grain and water in there.  

Did you batch sparge?  Are you stirring really well when you do?  
  
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Offline tschmidlin

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Re: Partial Mash help
« Reply #3 on: December 27, 2011, 11:01:59 AM »
Also, how was the grain crushed?
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Offline krustybb

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Re: Partial Mash help
« Reply #4 on: December 27, 2011, 01:24:04 PM »
Okay thanks for the feedback. Here is the grains that went in the mash tun. The outside tmp was about 75 degrees. I did not put hot water in first although I thought about it. I will try that.

4lbs- american 2 row
12oz - wheat malt
12 oz carapils
12 oz crystal malt 40L

I ended up adding a can (3.3lbs) of LME in a late addition and some sugar.

Final OG before yeast was pitched was 1.050

The sample I took in of the preboil wort was at 80 degrees or so I know it should be 60. That could of added a bit right?
Anyway. I think I used to much water for sure.

Also the grains were crushed at the homebrew shop three days before hand.
« Last Edit: December 27, 2011, 01:58:30 PM by krustybb »

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Re: Partial Mash help
« Reply #5 on: December 27, 2011, 03:48:35 PM »
Okay thanks for the feedback. Here is the grains that went in the mash tun. The outside tmp was about 75 degrees. I did not put hot water in first although I thought about it. I will try that.

4lbs- american 2 row
12oz - wheat malt
12 oz carapils
12 oz crystal malt 40L

I ended up adding a can (3.3lbs) of LME in a late addition and some sugar.

Final OG before yeast was pitched was 1.050

The sample I took in of the preboil wort was at 80 degrees or so I know it should be 60. That could of added a bit right?
Anyway. I think I used to much water for sure.

Also the grains were crushed at the homebrew shop three days before hand.


If your hydrometer is calibrated at 60* then at 80* at 1.050 is a 1.052.
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Offline duboman

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Re: Partial Mash help
« Reply #6 on: December 28, 2011, 08:19:56 AM »
It sounds as though you are on moving in the right direction in improving your methods, when moving to all grain it is very important to pay attention to all of the factors involved in mashing from the quality of the crush, all volumes for mashing and sparging, temperatures, water ph and calibrations of your measuring devices. As long as you pay attention to these items you will improve your results and once you dial in all your methods your final products will be more consistent.
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Offline krustybb

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Re: Partial Mash help
« Reply #7 on: December 28, 2011, 09:33:12 AM »
Thanks. This forum has been great in just easing the worries. I am formulating my next partial mash already. I have decided to try the same grain bill size but pre heat the cooler with warm water and to raise my strike temp a bit. Also I read that if you wrap a blanket around that can help loss as well.

My question though is is it worth the heat loss to open the mash cooler up to check it half way through. I think it is if I have hot water ready to add. But then how do you calculate that temp. What a fun and crazy hobby.

Offline duboman

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Re: Partial Mash help
« Reply #8 on: December 28, 2011, 09:42:58 AM »
Thanks. This forum has been great in just easing the worries. I am formulating my next partial mash already. I have decided to try the same grain bill size but pre heat the cooler with warm water and to raise my strike temp a bit. Also I read that if you wrap a blanket around that can help loss as well.

My question though is is it worth the heat loss to open the mash cooler up to check it half way through. I think it is if I have hot water ready to add. But then how do you calculate that temp. What a fun and crazy hobby.

+1 on the blanket if your cooler tends to lose heat. As for the stirring, since it is just a quick stir heat loss is is very minimal. I haven't had any issues.........just remember to be more attentive to all the other details involved  :)
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Re: Partial Mash help
« Reply #9 on: December 28, 2011, 07:48:06 PM »
Just reread the OP. 1.021 pre boil is not all that bad for 6.25 lbs of grain. When I doa 5 gallon batch of ordinary I use 7 lbs of grain and end up with a post boil OG of 1.032~. Which is right around 1.021 pre boil. so you are talking about ~70% efficiency. not bad.
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Jonathan I Fuller

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Re: Partial Mash help
« Reply #10 on: December 28, 2011, 11:38:38 PM »
My question though is is it worth the heat loss to open the mash cooler up to check it half way through. I think it is if I have hot water ready to add. But then how do you calculate that temp. What a fun and crazy hobby.

After the 15 minute mark I don't worry so much about the temp. I keep the lid closed.
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman