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Braumeister 50L misses OG on high ABV brews

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Ckilner

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I've been brewing with Braumeister for about 7 years now and have brewed over 6,700L so far - I've no idea where it's all gone!
The consistent problem I have always had is hitting target OG on high ABV brews. When I brew a 5% or lower I pretty much hit target every time. However, when I try to brew say a 7% or higher I invariably miss target.
My grain bill is always about 12kg and I reduce the water to increase the ABV (I use Beersmith for the calculations).
When I brew a 5% beer, my grain bill is about 12kg, I mash with 50L water, sparge with 15L and then top up with 12L and I hit 5% as planned.

My last brew was supposed to be 9%, using 40L water in the mash and then sparging with 10L. The actual OG turned out to be about 6.5%

Does anyone else brew high ABV beers in a BM 50L ?
 

kadmium

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I think the issue is the higher you go in gravity the less efficient you get, regardless of system, and the more grain you will need to use. Or you can top up with DME etc.

By reducing the volume you're reducing the grist ratio so I'm guessing that contributes to a reduction in efficiency.

You could try a reiterated mash or a longer mashing period perhaps?
 

Ckilner

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A good suggestion to mash longer. I'll try that first before a reiterated mash.
This is my mash schedule. Maybe increase the length of the Maltose step?

Mash In 55.0 C 5 min
Protein 62.0 C 10 min
Maltose 68.0 C 45 min
Saccharification 72.0 C 20 min
Mash Out 78.0 C 10 min
 

razz

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Two things that I have done in the past CKilner. Give the mash a stir every 15 minutes and use more sparge water (of course you will get a longer boil)
 

MHB

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Clinker, can you give your SG in the usual form (1.000), are you reading the potential alcohol scale on your hydrometer?
Mark
 

Ckilner

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Target OG = 1.092
Measured OG= 1.074
Both @20 deg C
 

MHB

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And your volumes to please, when ever you are looking at yields you need both.
Mark
 

Crusty

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A good suggestion to mash longer. I'll try that first before a reiterated mash.
This is my mash schedule. Maybe increase the length of the Maltose step?

Mash In 55.0 C 5 min
Protein 62.0 C 10 min
Maltose 68.0 C 45 min
Saccharification 72.0 C 20 min
Mash Out 78.0 C 10 min
I'd mash in closer to, or at protein rest temp. Even 5mins at 55, conversion takes off straight away. You might be flaffin around mashing in before the next step to 62. Try a Hochkurz mash for higher gravity beers. I've found it really boost efficiency. 30m @62, 30m @70, then mash out.
Failing all that, just set your brewhouse efficiency lower somewhere around the 68% mark in BeerSmith. It's common to have a lower mash efficiency with higher gravity beers.
 

MHB

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Been hoping for a bit more information but lacking that, best guess.
High ABV beer is always going to be a a lot less efficient and more expensive to make. Single vessel systems are really at their weakest at high ABV, much as I love my Braumeister this isn't what its best at.

There is a very handy little equation that helps a lot when designing a recipe. It is designed to give the Plato (oP) of the first running's, if you are full volume mashing its all first running's.
oP = CGAI/(L:G+CGAI
Where
CGAI is the potential yield of the malt, for this lets say its 75% or 0.75 in equation. Yield% or Y% for short
L:G being the mass of water /mass malt, lets say 5 water to 1 malt (5:1)
oP = 0.75/(5+0.75) = 0.13 or 13oP, an SG of (SG=(4*oP)/1000+1 = 1.052 Before the boil.

Pretty obviously the less water you use the higher will be the OG, the limit is about 2:1 any less water and the malt wont be covered
Using the same numbers as above except the L:G gives 0.75/2.75=27.3oP or 1.109
You are looking for an OG of 1.092 (23oP) 0.23 for use in equation
We can rearrange the equation to tell us the L:G
oP=Y%/(L:G+Y%) > L:G=Y%/oP
L:G=0.75/0.23 = 3.26, 3.26 times the mass of malt or 12*3.26=39.13L

We need to take a look at a couple of other factors to do with water. About 0.9L/Kg will stay in the grist and you should be getting at least 10% evaporation. You could go for a larger starting volume and a longer boil.
Boiling for more than three hours isn't recommended, you start causing measurable harm. I would be boiling a big beer for 90-120 minutes and aim for 15% evaporation, just because there is going to be a lot more high molecular weight proteins that we want to precipitate.
We cant do much about absorption by the grain but we need to add the loss to evaporation (10-15%) and its normal to allow another 2% for losses during mashing, say 12-17%. We need to add this to the water bill.

Say we aim for 15% evaporation, add the 2% and we need 17%, means the start of boil gravity should be 17% lower than the 1.092 or 23oP we want at the end of the boil. OG should be 23oP/1.17 = 19.66oP.
If we use the new target to calculate the L:G we get
L:G=0.75/0.1966 = 3.815, for 12kg of malt that's 45.78L

If you mashed in with 45.78L, 12*0.9 = 10.8L will stay in the grain, leaving 34.95 (well 35L) at the start of the boil, boil of 15% and you should have 29.73L that's very close to your target OG.

There are a couple of important caveats.
Make sure you have enough Calcium available, I would want at least 150-200ppm.
Make sure your pH is in the 5.3-5.5 range. If you haven't got a pH meter, use brew n water or one of the other programs to calculate your pH, you wont get down low enough with just salts you will need Acid as Acid Malt or an acid addition.

I would also look at your mash temperatures, you really don't want a protein rest, and mashing for much over 90 minutes isn't going to gain you much.
I would be tempted to mash in at around 62oC for 20 minutes (B-Amylase peak), raise to 66oC for 20 minutes, raise to 72 for 20 minutes (A-Amylase peak), mash out at 78 probably for another 20 minutes. Add another 16 minutes for ramp time and you are just over 90 minutes total.
There are at least three protease enzymes that work in the mashing range, there is at least one that wont fully denature under 65oC, it will do all the work you need early in the mash.
Lift the malt pipe and let it drain for the 20 minutes or so it takes to reach the boil.
Suck up the low efficiency, knowing you are making a mind blowing beer.
Mark
 

Talnoy

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I would be tempted to mash in at around 62oC for 20 minutes (B-Amylase peak), raise to 66oC for 20 minutes, raise to 72 for 20 minutes (A-Amylase peak), mash out at 78 probably for another 20 minutes.
What is the reason for the long mash out?
 

MHB

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Fair question, wouldn't apply on many systems, but the OP is brewing on a Braumeister, the sensor is in the bottom under the malt, it takes about 15-20 minutes of wort at 78oC rising through the malt bed and heating it as it rises for the top of the bed to reach the set temperature.
Any shorter and the top of the grain bed wont be at mash out.
A heavy wort is going to be less fluid than a thinner mash so it will drain a lot better if you make sure the top of the bed is at 78oC.
Probably should have mentioned that, also the 16 minutes of ramp time, BM50 rises at about 1oC/Minute from 62-78 will take about 16 minutes.
Mark
 

Talnoy

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the OP is brewing on a Braumeister
I happen to brew on a Braumeister myself as well, but on a BM20, do you think the time to get mash out temp in the top of the grain bed is the same on my smaller device?
 

MHB

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It's a lot less on my 10L and a bit less on the 200L at work, probably comes down to watts / liter. If I recall correctly the 20L BM has a 17500W, a better W/L than the 50L, the 10L has 1000W.
No rule says you have to wait 20 minutes but it wont do any harm. Given your pH is right and you have a sugary solution rather than water like most sparges you wont pull any tannins.
Think about a decoction mash, you are heating the grain to a boil and not getting tannins.
There are advantages to making sure the grain bed is fully heated to 78oC and spends some time at that temperature, some HMW protein will condense and get trapped in the grain bed, fines will get moved up in the malt and less will elute back into the boil as the wort drains...

Use a thermometer at the top of the grain bed, wait until its stable at 78oC, give it 10 minutes and move on, it will be close to 20 minutes.
Its your beer and if you feel 20 minutes is excessive do less, I find that on bigger beers it pays to give everything a bit longer.
Mark
 

Talnoy

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Use a thermometer at the top of the grain bed, wait until its stable at 78oC, give it 10 minutes and move on, it will be close to 20 minutes.
thanks a lot for the insight, some great advices there. I will definitely use this in my daily routine.

cheers,
Joakim
 

Coalminer

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10L is 1.2kw
20L is 2kw
50L is 2kw and 1.3kw
20L still raises at about 65seconds/degree C with 5kg grain and 27L liqour
 
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