Calculating Malt Quantities

[O1DMBFan]

Hello All,
Thanks for taking the time. I know there are plenty of software options out there to help in this process but I'd like to have a full understanding of how to manually calculate expected pre-boil/original gravity before leaning on those crutches. I believe I've got it figured out but would love some reassurance from my homebrewing brethren.

I doubt I'm doing this correctly but I'll lay out what I think I understand - do be gentle won't you?

Example Recipe - Simple Barleywine

Target Original Gravity (Post-Boil): 1.093
Target Volume: 5.5gal

Given 1hr of boil achieves a rise in gravity concentration by about 10pts. A 2hr boil should contribute roughly 20pts. I know this can vary based on many variables (volumes, ambient temp, altitude, etc) but we'll assume the 10pts per hour (unless there's a better method).

We'll be adding Brown Sugar(46ppg) around flameout, we'd like to add 25pts to our total gravity via brown sugar.
25 / (46ppg/5.5gal) = 3lbs

Expected Pre-Boil: 93 - 20 - 25 = 48 or 1.048

We'll assume an efficiency of 70% based on past brews:
Malt Bill:
30% - 2-Row (26.6ppg)
30% - Maris Otter (26.6ppg)
15% - CaraVienne (23.8ppg)
10% - C90 (23.8ppg)
8% - C70 (23.8ppg)
7% - C50 (23.8ppg)

48 x 7.5gal = 360 total points of needed sugar extracted from malt

2-Row Breakdown:
360 x 30% = 108
108 / 26.6ppg = 4.06lbs

Maris Otter Breakdown:
360 x 30% = 108
108 / 26.6ppg = 4.06lbs

CaraVienne Breakdown:
360 x 15% = 54
54 / 23.8 = 2.27lbs

C90 Breakdown:
360 x 10% = 36
36 / 23.8 = 1.51lbs

C70Breakdown:
360 x 8% = 29
29 / 23.8 = 1.22lbs

C50 Breakdown:
360 x 7% = 25
25 / 23.8 = 1.05lbs

Fingers crossed I didn't botch this up too badly. Let me have it folks!

Cheers,
O1DMBFan

 

[ESBrewer]

As I understand, 10% in your recipe is now 10% of total sugars of The wort, not 10% of total grain weight that might be more common in a recipe, I think. You will get a bit more special malts in grain weight than the % indicated because there is less extract in special malts. And a bit less base malts. Other than that your method seems to result in values that are expected.

For the boil you would like to know the boil off rate in gallons or pints per hour. How many points you gain during the boil depends on the wort gravity. If you boil it to half volume(you won't!) 1.030 comes about 1.060 but 1.050 would become about 1.100 (30 points vs 50 pts increase).

One more thing is that when you dissolve a lot of sugar the volume of the wort may change somewhat, but that may not be important, haven't done it recently. In general, dissolving certain substances will shrink the volume whereas with other substances volume may increase.

One more comment, your recipe has a lot of crystal malts (about 43% of the grain weight). The Barley Wine recipes I have seen (not many) contain less. Cara/Crystal does not contain the enzymes needed in mash and they contain some unfermentable so FG could be high, even for a barley wine. The high amount of brown sugar might help, though.

 

[O1DMBFan]

Thanks for the reply ESBrewer.

As I understand, 10% in your recipe is now 10% of total sugars of The wort, not 10% of total grain weight that might be more common in a recipe, I think. You will get a bit more special malts in grain weight than the % indicated because there is less extract in special malts. And a bit less base malts. Other than that your method seems to result in values that are expected.

Should I not be breaking it down this far then? Should I operate on % of weight or % of sugar when developing recipes? I figured % of sugar was the more controlled and accurate method rather than weight, since each grain contributes different ppg.

Thanks for the help in understanding!

 

[ESBrewer]

You are free to choose the method you like most, that is the beauty of homebrewing. I am just speculating. If the recipe is your own and you want a traditional barley wine you may want to look at some ideas such as

https://byo.com/article/barleywine/

https://learn.kegerator.com/english-barleywine/

https://www.homebrewtalk.com/forum/threads/crystal-malt-percentages-in-a-barleywine.511757/

 

[O1DMBFan]

You are free to choose the method you like most, that is the beauty of homebrewing. I am just speculating. If the recipe is your own and you want a traditional barley wine you may want to look at some ideas such as

https://byo.com/article/barleywine/

https://learn.kegerator.com/english-barleywine/

https://www.homebrewtalk.com/forum/threads/crystal-malt-percentages-in-a-barleywine.511757/

Thanks ESBrewer, I'm not interested in the specifics of the recipe. Just using it as an example.

Does anyone know what the "standard" would be? To refer to malt percentages based on volume OR possible extractable sugars?

 

[eric19312]

T
Does anyone know what the "standard" would be? To refer to malt percentages based on volume OR possible extractable sugars?

Percent by weight of the grain is how it is normally presented. When you read other people's recipes this is what is understood.