figuring out grain bill %'s

Brewing Processes
1

I know the percentages of grain I want,
but have to adjust them for efficiency.
  I tried using the method in Designing Great Beers to figure out
my grain bill. What this did was screw up my percents by weight.
I believe the book is giving me %'s by gravity per lb. ?
  So what I did was use the gravity per lb of the base malt
for all the other grains, so the weight %'s would stay constant.
  This seemed to work but I’m not sure it’s the correct way to
go about it. Are there any easier way to scale grain bills for efficiency?

I can put all #'s up if any one cares???

Thanks

2

Go ahead and put the numbers up if you want but then you really ought to look into some homebrew software.  Beersmith has a downloadable free trial version and it’ll let you scale recipes to your hearts content.

3

+1 - its like 25 clams - well spent, IMO.

4

+2

High mileage on that there beersmith model. Have it and love it.  8)

5

See if this works for you.

6

Here you go, good for starts - and it’s free…

http://sourceforge.net/projects/brewtarget/

7

I have brewtarget , but how do you go about resizing a batch
for efficiencies with it?

8

Thanks
The spreadsheet gave me the same #'s that I calculated by hand.
So I did something right.

9

Or I did something terribly wrong when I wrote it!  :smiley:

10

Why don’t you just figure out how much grain you need by assuming a standard 36 ppg for example? For this you need to know the efficiency, target volume and target gravity. If you want to be really precise with the extract potential of the grist you can calculate the weighted average by considering the extract potential of each malt and its grain bill portion.

Once you have the total grist weight the individual grain weights are easy to calculate from their percentages.

That’s how I do it.

Kai

11

I think that is what I did by
using the gravity per lb of the base malt
for all the other grains, so the weight %'s would stay constant.
???

12

I believe If you want to scale for efficiency you can simply do this for every grain weight:

new weight = (old weight * old efficiency) / new efficiency

Kai

13

get Promash!

http://www.promash.com/

great software

14

I’ll second the usefulness of Promash when dealing with fluxuating batch sizes and effeciencies.

To accomplish your grain bill amounts from a base recipe, you simply enter your base recipe and then click the lock ingredients box.

You can now adjust your batch size up or down and maintain the same percentages of grainbill.

15

Do you always go with the 36ppg when computing what efficiency you are hitting? Or do you try to use the extract potential of each individual malt? I’ve been trying to use exact numbers in my calculations but I am slowly learning that everyone’s numbers fluctuate by a few points for just about every malt!  So if I would just use 36ppg, maybe that would simplify things… but I don’t want to lose too much accuracy.

-red

16

I’m pretty lazy with that and tend to assume an extract potential of 77% for all malts ( don’t know if this is equal to 36 pppg, but it will be close). This is not necessarily correct but gets me close enough.

Most of the time I don’t even use efficienctly directly but simply use the grist weight that I used on a past beer which had the same or a similar OG. For example I know that I need to use a grist weight of about 4.2 kg if I want to make a 12 Plato beer with my system. I then know what malts I want to use at which percentages which gives me the individual weights for the malts.

Kai