Partial Mash Grain Bill Question

Hi everyone! Thans for all the help i have recieved on my prior two threads! I am about to begin formulating another recipe. It will be another partial mash....my 2nd.
I build my recipe based on the lierature "How to Brew" by John Palmer for ingredients, and use an online calculator for all the math and gravities ect. I have the capability to mash about 5-6 lbs of grain.
Now, in his book while referencing certain ingredients, he talks about usage per 5 gallon batch (ie For Chocolate malt he suggests 1/2 for brown ale, and 1 lb for porters and stouts). Pretty straight forward.
However, some grain he lists '% of grain bill' an amount or range which causes some confusion.
For example he suggests Bisuit Malt to be 10% of grain bill; therefore lets say my malts are:
- 3 lb DME (eqivelant of approx 5 lb base malt grain)
- 4.0 lb American 2 Row (mash)
- 1.0 lb Biscuit (mash)
From a flavor standpoint, by Biscuit malt is right on at 10% of the grain bill (converting the DME to an equivelant of basemalt).
Yet from an actual grain standpoint, my Biscuit malt is 20% of the grainbill. So if the grainbill suggestions are also meant for neccessary ratio for proper conversion, I am double the biscuit malt that i should be at. (Oh, and my example is for ease of math....I am not sure off the top of my head if Biscuit malt has any diastatic power to convert on it's own, let's assume it does't. i am not really curious about this specific recipe; rather i would like to know how grain bill in a partial mash affects conversion or if that is a non issue so long as i have SOME base malt in the mash)
Thanks!

You have to consider what the DME consists of. Most likely Base Malt and some sort of Crystal malt. Most likely it does not contain Biscuit Malt.

So if you were to add say 1 pound of Crystal Malt then the total Crystal Malt would be greater than 10% of the bill as there is some in the DME so you would need to adjust accordingly. Not so with the Biscuit. Adding 1 pound to that list of fermentables would keep it at 10% of the total bill.

I think.

OK, so in short, when there is a suggested % of grainbill or a reference to grainbill...and i am doing a partial mash, I include the DME equivelent (NOT just the grain).
PS, i figured the DME has some other stuff in it other than base malt, which is why i use the lightest Briess DME available. :^)

kgg_033 said:

OK, so in short, when there is a suggested % of grainbill or a reference to grainbill...and i am doing a partial mash, I include the DME equivelent (NOT just the grain).
PS, i figured the DME has some other stuff in it other than base malt, which is why i use the lightest Briess DME available. :^)

Click to expand...

Yes, and good job factoring what 3# of DME is in terms of Grain Weight. I thing I used to use 7# of Extract = 10# of Grain as a rule of thumb.

To be completely accurate, the percentage actually refers to the "quantity" of sugars you get from each ingredient. So in your example:

3# DME = 42pppg x 3 = 126 gravity points
4# two row = 36 x 4 x (assuming 70% mash efficiency) = 101 gravity points
1# biscuit malt = 34 x 70% = 24 gravity points

That's a total of 251 gravity points. So if you back out from that number, then your percentages are:

3# DME = 50.2%
4# two row = 40.2%
1# biscuit = 9.6%

If your mash efficiency improves, your percentages will change.

Thanks to all for the help. This also clarifies is why the book lists some mounts as % to grain bill, and others as amounts per 5 gallon batch. Certainly, flavors are still given off even if efficiency is horrible...so for something like Biscuit malt it may be ok adding additional biscuit malt to compensate, but i wouldn't want to overdo something like roasted barley to compensate for bad efficiency, lest my beer tastes like a carbonated starbucks

I understand your logic, but for me, I always go by my efficiency number, and I always build recipes by percentages. I say "I'm going to make an American pale ale and I want it to have:

7% Munich
5% crystal 20
2% crystal 40
and the rest is base malt

And then I figure out what the poundage should be of each malt, based on percentage and mash efficiency. And then I go to the LHBS and get my grains, down to the hundreth of a pound. So for the above recipe (1.058 OG, 75% efficiency), I bought:

.95# Munich
.70# crystal 20
.28# crystal 40
11.39# Maris Otter

If my efficiency were 65%, I would by buying more grain, but I would still maintain the percentages. If this were a stout, I'd be doing exactly the same thing - more roast barley, more chocolate malt, more crystal, etc.

I really don't like this idea in homebrewing that ingredients are built on quarter-pound increments.

I echo that sentiment "I really don't like this idea in homebrewing that ingredients are built on quarter-pound increments."
My Home brew store only sells by the pound, and i have a cheap plastic analog scale. In addition, I have only mashed once (JUST set up my bucket in bucket system) so i have very little to go by in terms of guessing efficency. i anticipate it will only go up from the 59.5% from batch #1. For that reason I currently build my recipes based on 1/4 lb increments. But i am very maticulous and detail oriented (analyst and finance background), so no doubt when i begin to get a feel for this, i will be building my recipes the same as you.
Quick Question in light of this. So may last recipe is a High Gravity Stout. I did NOt up my malts as you just suggested to maintain percentage grain bill. Only upped my DME for the higher gravity. Therefore, would you say this will still have that stout style taste? For reference:
Mash: 3lb two row, 1lb roasted barley, 3/4lb chocolate malt, 1/2lb medium crystal
DME: 7lbs
OG: 1.083
I am now wondering weather I was too light on my specialty grains

That's still a good amount of roasted grains. It's not like it's going to be a brown ale. It will probably be black as night. It's a relatively low amount of crystal (maybe 2-3%) but the higher OG will mean a higher FG, so you'll get some sweetness. Should be a tasty beer if fermentation goes well.