Partial Mash: Question about procedure and batch sparging..

I've done 2 partial mashes and have ingredients ready to go for my 3rd. My first partial mash came out perfect, while my 2nd had an original gravity much lower than the target(1.060 vs 1.092). So the first thing I want to do is explain my process for my last partial mash that didn't reach the target OG.

I have a 3 gallon mash tun that is a converted water cooler pictured below. I had 4.75lbs of grain so I used 1.25qts/lb to get 1.484 gallons to mash with. I placed my grains in a paint strainer and placed them into my tun. I heated the water up to 174 in an attempt to reach a mash temp of 155. I poured the water over the grains than used a paddle to push and prod the grains to try and make sure their weren't any pockets that weren't coming in contact with the water. I screwed the lid on and covered it with a blanket. The instructions called for 45mins.

I then pulled a few pints and recirculated it into the top of the tun until it was clear. I then drained the tun into my 8 gallon brew pot. (The brew pot had 3.5 gallons of cold water in it which I figured would make a little over 6 gallons when I got the first runnings and sparged. I then heated up an equal amount of water as the mash (1.484 gallons) to 170 and poured it into the tun. I prodded the grain a little bit and then drained that into the brew pot. I was now up to my desired preboil water volume and went ahead and brought it up to boiling, removed from heat, added the liquid extract, boiled and started adding hop additions.

So I can think of a few mistakes I probably made. When I took the temp of the mash after 45 mins it was only 144. So I'm thinking it was too cool of a temp for the 45 mins to extract all of the sugars. I did a test on my cooler with just water this week and it loses about 10 degrees over an hour. The major culprit I think is the lid. It's very thin and gets very hot unlike the rest of the tun. Is there anyway to fix this? Also I think I'm supposed to put the water in the tun and then submerge the grains...is this correct? Also I think I should have been adding the wort I made in the tun to water that is being brought up to a boil, is this also correct?

When it comes to the batch sparging, I used the some amount of water I did for the mash. When it comes to all grain it looks like you batch sparge with the amount of water you need to bring the brew pot up to the pre-boil water volume. How much should you use when partial mashing? I think I read you don't want to use too much because it will extract tannins from the grain.

Could someone help me out with my questions and point out any other mistakes I made. Thanks a ton, I greatly appreciate your help.

I actually did something very similar to what you did today. I was mashing for an hour in my brew kettle using the BIAB method, and I checked the temperature at the end at it was 144, so I lost about 10 degrees as well.

Did you check your gravity after you got all of your extract and runnings into the kettle? I broke my hydrometer today also, so I couldn't really do that. I'm interested to know because I would like to know if I actually got conversion during my mash or not.

Sorry I can't offer any explanation, but I did have a similar experience.

Temp drop: Just insulate with blankets or towels. You could also set the mash tun in your sink with the same temp water surrounding it to increase the thermal mass. Doing a small decoction halfway through would also work to raise the temp bakc up. I use food grade buckets for mashing and lautering and just wrap them with towels and blankets to insulate. I don't get any temp drop over an hour but there is more thermal mass.

I usually add the water first and then the grain. Make sure there are no dough balls by stirring.

Mashing for a full hour will give you better conversion most of the time.

You will get better efficiency with a continuous sparge and it really doesn't take any more time. If you batch sparge, let the mash sit for 10 minutes or so after adding the second lot of water. Doing a third batch of water wouldn't hurt either.

Also, keep some DME around in case you miss your gravity, that way you can bring it up if you fall short.

For a few dollars more you could set up a Papazian Zapap mash/lauter tun and have more thermal mass. You could also do all grain. These work great for partial mashing as well because you can add ALL of the sparge water at once and then just trickle out into your kettle. Just myu opinion but I tend to think the plastic in the food grade buckets is a bit higher quality than in a cooler. I have over 30 all grain batches under my belt with this system with excellent results.

devilishprune said:

Did you check your gravity after you got all of your extract and runnings into the kettle?

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I actually didn't think to take a reading.

JonK331 said:

Also, keep some DME around in case you miss your gravity, that way you can bring it up if you fall short.

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How do I figure out how much DME to add if my target pre-boil gravity isn't reached? I usually keep some around for making starters, so I'll just have to make sure I have enough before brew day in case I need it.

JonK331 said:

For a few dollars more you could set up a Papazian Zapap mash/lauter tun and have more thermal mass. You could also do all grain. These work great for partial mashing as well because you can add ALL of the sparge water at once and then just trickle out into your kettle. Just myu opinion but I tend to think the plastic in the food grade buckets is a bit higher quality than in a cooler. I have over 30 all grain batches under my belt with this system with excellent results.

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Thanks for the tip on the Zapap mash/lauter tun. I haven't heard of this and was thinking of using a rectangular cooler shortly when I start all grain. After looking at this I think I might just go with the Zapap.