crayfisher
Active Member
I got bought the Greg Hughes book 'home brew beer' and was wondering if there is a reliable way/rule of thumb to scale the recipe's down to a gallon. Cheers for any advice.
scaling down recipes
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crayfisher
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Thanks for your help
stz
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Ideally you learn your system and learn how to scale recipes to your system. I can't say 'take 300kg of malt to produce a beer of 5%' because it is meaningless without knowing mash efficiencies, starting gravity, final gravity, attenuation and so on. This also applies to hopping. You want to be in a position of being able to take anything like an abv, a starting gravity, a final gravity, an apparent attenuation and use that to build a mash schedule, fermentation profile with a known or unknown yeast and just use percentages for grist and hopping.
Like ... If somebody say 90% pale malt, 8% munich and 2% torrified wheat for an average attenuation of 80% using a typical english ale yeast fermented to promote moderate esters hopped using a neutral bittering charge for 80% of the IBU's and fuggles for the rest at knockout for 34 theoretical IBU's with a starting gravity of 46 .. you should be able to build a recipe to suit your system.
Say I want 5L at the end. I want 6L in the fermenter to accommodate for losses to fermentation and packaging.
I need 6L @ 46 which is 276 total extract. 90% from pale malt @ 299LoD 8% from munich at 260LoD and 2% from torrified wheat @ 305LoD.
If my mash and sparge process yields 85% efficiency I need 325 total extract.
325/100*90/299 = 978g pale malt, 3.25*8/260 = 100g munich and 3.25*2/305 = 21g torrified wheat.
6600ml needs to get into the copper to allow for 10% evaporation during a 60m boil.
You need to add 1100ml of absorption for a total liquor usage of 7700ml with 2860ml for the mash and 4840ml for the sparge.
Getting there!
I want 34 IBU's with 27 from a bittering charge. I'm going to use columbus at 14% AA. At a gravity of 46 hop utilisation is approximately 0.240 over 60m so 24 * 6 / 10 / 0.240 / 14 = 4.28g. The remaining 7 IBU's come from fuggles at knockout which with a 30m steep might as well be a 5m boil which is a utilisation of approximately 0.048. Fuggles at 5% AA so ... 7 * 6 / 10 / 0.048 / 5 = 17.5g.
I'll use 4.28g of columbus @ the start of the boil and 17.5g of fuggles at knock out for a steep.
If I want to use SO4 yeast which has an average attenuation of 75% I'd need to mash slightly cooler than normal, 64-65C. I need some esters so I'd not really want to over pitch though a warmer than normal fermentation would be ideal to push esters and attenuation so maybe I'd pitch at 21C and allow to rise to 23C at hour 24. If I was using nottingham yeast I'd mash higher to accommodate for its higher attenuation.
Anyway. I could go on, but recipes should be scaled to the system. You might get away with fractions, but they don't really work like that. You might find it more to learn about and work out, but once you know how to do it you can do pretty much anything? It is also cool to be able to understand why some aspects are essential, but others just nice to have or pretty much optional.
Like ... If somebody say 90% pale malt, 8% munich and 2% torrified wheat for an average attenuation of 80% using a typical english ale yeast fermented to promote moderate esters hopped using a neutral bittering charge for 80% of the IBU's and fuggles for the rest at knockout for 34 theoretical IBU's with a starting gravity of 46 .. you should be able to build a recipe to suit your system.
Say I want 5L at the end. I want 6L in the fermenter to accommodate for losses to fermentation and packaging.
I need 6L @ 46 which is 276 total extract. 90% from pale malt @ 299LoD 8% from munich at 260LoD and 2% from torrified wheat @ 305LoD.
If my mash and sparge process yields 85% efficiency I need 325 total extract.
325/100*90/299 = 978g pale malt, 3.25*8/260 = 100g munich and 3.25*2/305 = 21g torrified wheat.
6600ml needs to get into the copper to allow for 10% evaporation during a 60m boil.
You need to add 1100ml of absorption for a total liquor usage of 7700ml with 2860ml for the mash and 4840ml for the sparge.
Getting there!
I want 34 IBU's with 27 from a bittering charge. I'm going to use columbus at 14% AA. At a gravity of 46 hop utilisation is approximately 0.240 over 60m so 24 * 6 / 10 / 0.240 / 14 = 4.28g. The remaining 7 IBU's come from fuggles at knockout which with a 30m steep might as well be a 5m boil which is a utilisation of approximately 0.048. Fuggles at 5% AA so ... 7 * 6 / 10 / 0.048 / 5 = 17.5g.
I'll use 4.28g of columbus @ the start of the boil and 17.5g of fuggles at knock out for a steep.
If I want to use SO4 yeast which has an average attenuation of 75% I'd need to mash slightly cooler than normal, 64-65C. I need some esters so I'd not really want to over pitch though a warmer than normal fermentation would be ideal to push esters and attenuation so maybe I'd pitch at 21C and allow to rise to 23C at hour 24. If I was using nottingham yeast I'd mash higher to accommodate for its higher attenuation.
Anyway. I could go on, but recipes should be scaled to the system. You might get away with fractions, but they don't really work like that. You might find it more to learn about and work out, but once you know how to do it you can do pretty much anything? It is also cool to be able to understand why some aspects are essential, but others just nice to have or pretty much optional.
