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Beersmith and IBUs

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Proofman

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I use beersmith alot. Every recipe I do (partial mash) I enter it into beersmith no mater where the rtecipe comes from (BYO, Books, my own recipes, etc.). When I enter the recipes into Beersmith, and I do it exactly as given, or a closely as possible, I end up with beersmith giving IBUs about 20-30% less than what the recipe called for (boil volume, extract addidtion times). Sometimes I adjust the recipe so the IBUs match the original, sometimes I don't. Some of these are clones and it seems more often that if I leave it as is it is closer to the original. I can taste the difference. I know if I go to the hop bitterness tool and enter the parameters under "Rager" the IBUs are closer to the original recipe. Is there an adjustment I haven't found? I
 
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Proofman

Proofman

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I do full volume boils, and I understand how it affects utilization. What I always do is enter the original recipe then make adjustments.
 

Beerrific

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I do full volume boils, and I understand how it affects utilization. What I always do is enter the original recipe then make adjustments.
Why not just brew as printed? If you use exactly what they are using (amounts adjusted to account for differences in %AA of course) then you should then be getting what they intended. Once you have brewed a couple this way you can then use what ever program and say "Well BeerSmith says it is xx IBUs....I would like my next beer to be more bitter, say (xx+10) IBUS" and then just go for xx+10 IBUs as prescribed in BeerSmith. In other words, just choose a method/formula, stick to it, and calibrate your tastes to this. All these IBU ratings are just guesses anyway.
 

Kaiser

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Don’t get to hung up on the IBU numbers that you get out of the brewing software. They are estimations based on what other home brewers, who measured their IBUs, got. You may have to adjust the numbers based on previous experiences (achieved vs. desired bitterness level) that you had with your system.

There are a number of different formulas out there (Tinseth, Raeger, Garez, Ray Daniels ….) which will give you different IBU estimations. Chances are that the recipe was calculated with a different formula than you have selected in Beersmith. I suggest sticking with one formula and getting a feel for how far your IBU numbers are off from what you think the actual bitterness should be.

Kai
 
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Proofman

Proofman

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Don't get me wrong. I'm not getting hung up on the number. I was just wondering if there was something in the program I was missing. The only problem I had with this was when I did my own brown ale. I wanted something malty with low hop bitterness and I didn't take this topic into consideration. As a result, it was more bitter than I desired. But I still drank it all.
 

Kaiser

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I wanted something malty with low hop bitterness and I didn't take this topic into consideration. As a result, it was more bitter than I desired. But I still drank it all.
Happened to me on one of my early batches ;) A SNPA clone that called for 37 IBU. I did the calculations and ended up with an almost undrinkably bitter batch. This is when I learned, that I have to shoot more towards 30 IBU when making a beer that should be as bitter as SNPA.

Later then I realized how flawed the bitterness estimation is. But once you know the limitations you can work with it fairly well.

Kai
 

david_42

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The real formula for utilization is a bit complicated (it's an asymptotic function that depends on wort composition, gravity and temperature), so software just uses approximations. That's one of the reasons you'll see people claiming 100+ IBU for beers, even though that is a very real limit if you are boiling at sea level or higher.
 

BeerSmith

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Hi,
BeerSmith uses Tinseth by default which is great for full boil beers, but will give you a lower number than Rager. Many books and brewers traditionally used Rager because it was a bit easier to calculate. Rager is considered a bit better for partial boil batches. Some books and magazines also use a "flat" utilization of about 30% which is, quite frankly, not very accurate.

Personally I use Tinseth, as do most all grain and full boil brewers. It is a matter of preference.

You can adjust what formula is used in recipes from the "Bitterness" tab of the Options dialog (tools menu).

Cheers,
Brad
 
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I like Tinseth because it's what I've become accustomed to using. That doesn't mean it's the most accurate, though I've read some articles that support much of what BeerSmith says, above. Even if I found out that another algorithm is more accurate, I would stick with Tinseth. I get repeatable and expected results because I use a consistent method. Pick one that works for you, and stick with it.

When brewing other people's recipes, just recognize that the bitterness number is an estimate, while the ingredient amounts are exact. Generally, the only time I tweak the bittering hops is when AA% is given in the recipe, and my hops differ slightly.
 
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