How to use BU/GU Ratio to design better beers

I'm really more of a session beer drinker (3.5%-3.8% and possibly lower) but I do enjoy a wide variety of beer styles. No real reason, but I'm quite a small guy who can't drink as much as others. I enjoy making all beer styles around this ABV, which poses a lot of its own challenges.

I was talking in the chat last night about using the BU/GU ratio and how complicated it generally is to use, so set out to make a calculator. Fortunately with a little googling one already exists, so I thought I'd share.

http://www.tc.umn.edu/~rohw0009/homebre ... bvcalc.htm

What is BU/GU ratio?

There are many schools of thought on how to correctly bitter a beer, including whether the OG or FG should be used as a guide, three common hop bitterness algorithms and a wide variety of bittering hops available. This is just one idea that uses the Original Gravity of a beer to determine how many IBUs you should use in your beer depending on the style.

The advantage here is that you can generally brew most beer styles at any ABV you wish and still retain the balance of the style. Your American Pale Ale at 2% will remain hoppy but not overly so, and your extra strong wheat beer will still have the delicate balance between maltiness and bitterness at 10%. Popular beer recipe calculators tend not to supply much information about this method of working, and instead rely on BJCP guidelines for colour, bitterness and gravity, without much thought for the overall balance.

Using the calculator

To use the calculator when formulating a recipe, simply use the right hand calculator "Calculating IBU needed." Input your Original Gravity, Final Gravity (or estimated FG) and desired Balance Value, which can be found for your chosen beer style by following the figures at the BOTTOM of the table - the top "BU/GU" and is just a resulting measurement.

Even though this is mathematical, use your common sense and creativity.

A Double IPA at 100 IBU might be excessive even if the calculation is correct. You might be using a very low attenuating yeast or dextrine malts for a sweeter/fuller body, in which case you might want to dial in a few more IBUs than calculated. Milk stouts and scotch ales should err on sweet, so if you're brewing one at high ABV, take the recommended IBU with a pinch of salt. Spices and roast malts can add perceived bitterness, or very dry yeasts (such as a Saison yeast which can finish around 1.002) and these might all require a little less bitterness.

Thanks Rob. Thus is something I've been meaning to look more into for many months; this should make it much easier to do.

[graysalchemy]

Thanks for sharing. Something which is quite often overlooked and not understood by many.

[Dennis King]

Very good Rob.

Cheers Rob,

using the calculator today to try and brew a balanced APA.

Greg

That's what I brewed with it last and at 3.8% it's nice and balanced.

Spot on Rob, the BU:GU ratio is what I use for all my beers