Double mash with Braumeister 50L

[Ckilner]

I'm considering doing a high ABV brew with a double mash. I'm using Beersmith 3 and I'm familiar with using it.
For my single mash brews I have set BH efficiency at 72% and this seems to be pretty accurate for normal session beers. I thought I'd have a go at a double mash.
If the efficiency of the first mash is 72%, would the efficiency of the second mash be 72% of 72%, i.e. 52% ?

 

[kadmium]

I'm considering doing a high ABV brew with a double mash. I'm using Beersmith 3 and I'm familiar with using it.
For my single mash brews I have set BH efficiency at 72% and this seems to be pretty accurate for normal session beers. I thought I'd have a go at a double mash.
If the efficiency of the first mash is 72%, would the efficiency of the second mash be 72% of 72%, i.e. 52% ?

By double mash you mean reiterated mash?

Just go on the single figure, and plan for your usual efficiency. Then split the grain in two and mash. At the end, work out your efficiency and adjust as needed next time.

If you come in low, add some DME, if you come in high top up.

 

[MHB]

Where I work the boss did a double brew barley wine on the 200L BM, I'll see if I can get the numbers and scale them down to 50L for you.
When I use either my own or works BM I normally get more like 82% efficiency at Kettle Full (Wort in the kettle after the malt pipe has been lifted). Might be worth looking at your water chemistry, pH and all that.

What sort of gravity are you looking for?
There are a couple of other ways to get high gravities.

Just cutting the water back, I think about 35L is the minimum you could get away with in a 50L BM (enough to fill the malt pipe and for the pump to have something to work with. If your malt had a Yield potential (Y%) of say 76% CGAI (coarse grind as is) and you mashed 13kg of malt your kettle full gravity would be
oP First Runnings = Y%/L:G+Y% from above 0.76/((35/13)+0.76) = 0.22, or 22oP or 1.088 before the boil.

Adding some DME will get you where ever you want to go, its quicker and pretty convenient way to make high gravity beer, use all your specialty malts in the mash and just rely on the extract for gravity.
Mark

 

[Ckilner]

Where I work the boss did a double brew barley wine on the 200L BM, I'll see if I can get the numbers and scale them down to 50L for you.
When I use either my own or works BM I normally get more like 82% efficiency at Kettle Full (Wort in the kettle after the malt pipe has been lifted). Might be worth looking at your water chemistry, pH and all that.

What sort of gravity are you looking for?
There are a couple of other ways to get high gravities.

Just cutting the water back, I think about 35L is the minimum you could get away with in a 50L BM (enough to fill the malt pipe and for the pump to have something to work with. If your malt had a Yield potential (Y%) of say 76% CGAI (coarse grind as is) and you mashed 13kg of malt your kettle full gravity would be
oP First Runnings = Y%/L:G+Y% from above 0.76/((35/13)+0.76) = 0.22, or 22oP or 1.088 before the boil.

Adding some DME will get you where ever you want to go, its quicker and pretty convenient way to make high gravity beer, use all your specialty malts in the mash and just rely on the extract for gravity.
Mark

What grain crush size do you use? I have set mine to 1.2mm. I wonder if that's why my efficiency is 72% and not 82% like you. I use Brunwater for my water additions.

 

[MHB]

Its a bit more complicated than that, I normally double crack at about 1.4mm. But the mill has 175mm rollers that are spiral fluted and its rated to crack 1.1 ton/hour (44 bags) so I would be real careful with just a gap number.
Believe me a good mill makes a big difference, as can the speed the rollers are going, how well the malt is feeding in...

The L:G and how well you sparge are more likely to be making more difference than the gap. Given you aren't doing a short or otherwise limiting mash regime.
As an example, say we mashed 1kg of grain with 75% (CGAI) yield potential, at full volume (no sparge) and allowed it to drain well so 0.9kg of water was retained the wort gravity and efficiency would look like this: -

Worth remembering that the Congress Mash (how potential is measured) is conducted at a L:G of 8:1.
Also assumes that you are getting almost complete conversion. We can play around with the numbers and its pretty easy to see that effective sparging will really up your efficency.
Mark