unsure of recipe for next batch - input needed

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

myersn024

Well-Known Member
Joined
Jul 18, 2006
Messages
113
Reaction score
0
My next batch is going to be a german pilsner, and according to promash I should wind up with an OG of 1.050. I want to boost that number to be a little closer to 1.060 using an extra pound of DME. How much extra bittering hops would I need to counteract the extra sugar? The recipe is below.

1 lb Carapils (steeped for 30 minutes at 155)
6 lbs of pale LME
1 oz Halltertau (60 minutes)
1 oz Hallertau (10 minutes)
.5 oz Saaz (flavor)

I have an extra 2 oz of Hallertau that I can use if I need them, but I don't know how much extra to use. Input is appreciated.
 
I suppose if i am not sure i should not post, but if i never offer up stupid ideas then i will never learn.

How about this, since you are using only 1 oz for bittering with 6 lbs of LME, then look at it like it is a 1:6 ratio. so add maybe 1/6 of an oz.

perhaps this is way off.

Reverend
 
Makes since to me, but then again I don't have any real idea either. Definitely food for thought though.

Anyone else?
 
Rev JC is on the right track.

What you want to do is maintain the ratio between IBUs and gravity, sometimes abbreviated as BU:GU.

From Promash, get the IBUs and OG of the original recipe. Figure out the BU:GU ratio, then multiply your new (higher) OG by that ratio to get your target IBUs. Now trial&error the bittering hops until you hit the right amount.

Just increasing the hops by whatever factor you increased the gravity by won't exactly get you there, since increasing the gravity decreases the hops utilization rate a bit.
 
Just in case you don't know...
Gravity Units (GU) = [(OG - 1)*1000] * gallons of wort

i.e. OG 1.055 in 5 gallons would be:

55*5 = 275 GU

So your IBU for this recipe will probably be somewhere in the neighborhood of 30, and that would make your BU:GU ratio = 9.17 (substitute your figures in to determine the exact ratio). So to keep this ratio constant, if you increase the GU to 300 (60*5) then you'd need to increase the BU to around 33 (300/9.17). There's plenty of ways to do this...probably the easiest of which is to just throw in an extra 1/4 oz of Hallertauer at the boil. The only reason that Revrend JC's method isn't the same as this, is that hops additions don't parallel BU increase in a 1:1 fashion; it changes based on when you add them in the boil.
Keep in mind that beer math was meant to be done when drinking beer...so most things are pretty straight forward :drunk: (who knows what would happen if it wasn't).

Cheers,
Marc.
 
I've never seen BU:GU done this way. Since the calculation for hops untilization (and hence IBUs) is dependant on both volume and gravity, there's not reason to take batch size into account.

BU:GU is generally expressed as

IBU / (SG - 1) * 100


So a 1.050 APA with 40 IBUs would have a BU:GU ratio of .8


40 / (1.050 - 1) * 100 = .8

or, in other words...

40 / 50 = .8
 
hmm...I guess it all depends on what units you want...GU's per gallon, or total GU's. At any rate, if you use either ratio to make adjustments you get the same answer. But it looks like I've been using the wrong formula...muchas gracias Cweston.

Marc.
 
mbreen01 said:
hmm...I guess it all depends on what units you want...GU's per gallon, or total GU's. At any rate, if you use either ratio to make adjustments you get the same answer. But it looks like I've been using the wrong formula...muchas gracias Cweston.

Marc.

Yeah, I think it works either way--you're way just seems to have an unecessary component to the calulation.

I think BU:GU is the one concept you really need to grasp in order to design or alter recipes successfully.
 
You can download the free evaluation copy of Promash here. It is a program that does a lot of brew calcuations for you, allows you to scale up/down a recipe, calcualate IBUs, anticipated OG, etc. Quite handy for the all-grain brewer, and even pretty handy for the extract brewer. Check it out.

Marc.
 
ProMash is very handy. You can create/edit/save 3 recipes. After that you can still look at any recipe and even edit it, but not save it. It's a great program...give it a try.
 
Back
Top