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Old 10-05-2013, 02:54 AM   #1
adamjackson
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Default Correcting expected mash gravity with thick mash

Total Grain - 28 pounds
Mash tun - 10 Gallon igloo w/ false bottom
Mashed in at 165 with 8 gallons of water (beersmith said I needed 10 gallons)
Mash details - 152F for 120 Minutes

First runnings were around 1.100 @ 148 F
As I sparged and continued the extraction, I ended up coming in at around 1.075 @ 155

One key issue here was that the sparge appeared to be stuck, clogged false bottom, etc. Where there was still water above the bed (pre-sparge) and it wasn't just rushing out like usual. I used the paddle to loosen things up a bit and eventually just spun it making holes in the bed for water to pass

and I think that's where I get wrong. Without a grain bed set, the wort was just going straight through the holes I made and not the bed

So instead of an expected efficiency of 65%, my post-mash efficiency was 40%

=====

Here's how I corrected this and I really hope it doesn't go badly. First, I removed 1 of the 2 ounces of Magnum from the boil to reduce expected IBUs from 100 to 80 (now that there are less sugars)

I also kept sparging in my 7.5 gallon brew kettle until I got 7 gallons of wort. I use fermcap so I just have to watch it carefully but haven't had any boil over. and my plan is to do a 90+ minute boil until the wort volume is at 5 Gallons

This way evaporation will help me out a bit...I won't be at the expected OG but at least I'll be at 50%


Thoughts? I mean, right now, it's too late to apply any advice but next time, I'd love to know what I did wrong. I think this is it.

1. More grain than my 10 gallon cooler could take
2. Mash was too thick, needed more water
3. I should have somehow eliminated the stuck sparge
4. I should have sparged slower


Sigh.

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Old 10-05-2013, 04:31 AM   #2
BrewMasterFlash
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Quote:
Originally Posted by adamjackson View Post
Total Grain - 28 pounds
Mash tun - 10 Gallon igloo w/ false bottom
Mashed in at 165 with 8 gallons of water (beersmith said I needed 10 gallons)
Mash details - 152F for 120 Minutes

First runnings were around 1.100 @ 148 F
As I sparged and continued the extraction, I ended up coming in at around 1.075 @ 155

One key issue here was that the sparge appeared to be stuck, clogged false bottom, etc. Where there was still water above the bed (pre-sparge) and it wasn't just rushing out like usual. I used the paddle to loosen things up a bit and eventually just spun it making holes in the bed for water to pass

and I think that's where I get wrong. Without a grain bed set, the wort was just going straight through the holes I made and not the bed

So instead of an expected efficiency of 65%, my post-mash efficiency was 40%

=====

Here's how I corrected this and I really hope it doesn't go badly. First, I removed 1 of the 2 ounces of Magnum from the boil to reduce expected IBUs from 100 to 80 (now that there are less sugars)

I also kept sparging in my 7.5 gallon brew kettle until I got 7 gallons of wort. I use fermcap so I just have to watch it carefully but haven't had any boil over. and my plan is to do a 90+ minute boil until the wort volume is at 5 Gallons

This way evaporation will help me out a bit...I won't be at the expected OG but at least I'll be at 50%

Thoughts? I mean, right now, it's too late to apply any advice but next time, I'd love to know what I did wrong. I think this is it.

1. More grain than my 10 gallon cooler could take
2. Mash was too thick, needed more water
3. I should have somehow eliminated the stuck sparge
4. I should have sparged slower

Sigh.
From everthing I've read I'd recommend using rice hulls to your mash. 1/2 lb per 10 lbs of grain. It won't add any flavor or color either.Good luck
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Old 10-05-2013, 02:17 PM   #3
ronjonacron
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Quote:
Originally Posted by BrewMasterFlash View Post

From everthing I've read I'd recommend using rice hulls to your mash. 1/2 lb per 10 lbs of grain. It won't add any flavor or color either.Good luck
I use two handfuls of rice hulls in all my 5 gallon batches. Theyre super cheap and a pound will last 4 or 5 batches.

Also, a red flag shouldve gone up when it told you 10 gallons of strike water for a 10 gallon cooler. Beersmith is cool, but i really only use it to formulate recipes. Greenbayrackers.com has a can i mash it section that has been really helpful for me. It calculates how much space you will need for grist and desired mash thickness.
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Old 10-05-2013, 04:55 PM   #4
acidrain
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I batch sparge, so I may be off base here, but don't you run a little to see how the grain bed is performing?
If you get a stuck sparge, instead of just poking holes in the grainbed, doesn't it make sense to thoroughly mix up the grain (prior to adding sparge), and then run (vorlauf) to make sure you have a nice grainbed set and good flow?

Also, are you saying that you took hydrometer readings and corrected for temps at 148F and 155F? Hydrometer readings are not reliable at those temperatures. Use a refractometer if you don't want to wait for samples to cool.

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