Which IBU calculator do you use & why?

Well, the title says is all. In the past, I have always made my own recipes up, based on fond memories of beers drunk in the past, so I haven't paid any attention to IBUs. I have used AAUs, since these are self consistent within my little brewing world.

Now, based on reading the long SNPA cloning thread on Northern Brewer's forum, I am inspired to try that recipe. The problem I am running into, is that is seems there are lots of IBU calculators out there, and I can't figure out which one to use to match the SNPA IBU target.

Can anyone recommend one? Or, if you've made the SNPA clone based on Beerfan's recipe. what calculator did you use, and how did the beer turn out?

I use BeerSmith software; not only a IBU calc. but a full fledged brewing package... Free to try for 20 days or something and $19.95 to buy. Great program though!

I use Beersmith, too. It uses the 'Tinseth' calculation by default but you can change which formulae it uses.

However, it is worth remembering that IBUs are affected by many, many different factors and one calculation is no better than another. It's unlikely you'll get exactly the bitterness you're looking for first time, but you will have a reference point for your next brew.

Once you get into the real high IPU numbers, all the programs begin to break down. When they look at the actual IBU content of beers chemically, it seems that you can't get more than 100 IBUs in solution. Yet, the programs will come up with calculations showing 278 IBUs, for example. I just did an IPA that supposedly is 90 IBUs, but I highly doubt it.

In any case, if you are consistent with one program or calculator, you'll still get good info. But, 60 IBUs for you may be 70 IBUs for someone else, or 50 in reality.

the_bird said:

In any case, if you are consistent with one program or calculator, you'll still get good info. But, 60 IBUs for you may be 70 IBUs for someone else, or 50 in reality.

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the_bird is right (though at times convoluted - how could he spout pure content for 4000+ posts? ) - As long as you take good notes and use the same method of calculations every time, you're all good.

Hey, if I were a "real" post whore, I would have said "Be consistent and you're good!" and not brought up the issue of the numbers aren't terribly accurate to begin with.

Although, a "real" post whore would also feel the need to respond to your comment....

You doubt my hopwine???

I do too. It's a classic example of the calculators failing. It's actually a little on the sweet side with the raisin flavor dominating. I suspect I would have gotten the same actual bittering with one oz. of Columbus. Since it was a very old recipe, the original hops were probably much lower AA%.

Hops (ounce) x AA X % Utilization Divided by 6.7 (5gallonx1.34)

Depending on your system 60 min boil=30-35 %, 30 min=15-17%, etc...

ex: 1oz 8AA hops boiled for 60 min= 1(8)(30)/6.7=35ibu

Thats what I use...It may not be dead-on-balls accurate but it works well enough for me.

Thanks folks. The one real unknown is the % utilization. For example, assuming a 60 min 1.050 gravity full wort boil, this seems to range from 20% (Garetz) to 30% (Rager); that's a dirty great big range. So who's right, and what's their evidence? I agree with the responses that counsel a trial and error approach, I just want to see if there is some good basis for choosing a % utilization.

What do professional brewers do? Get the AA content measured? Beyond my means...

AiredAle said:

Thanks folks. The one real unknown is the % utilization. For example, assuming a 60 min 1.050 gravity full wort boil, this seems to range from 20% (Garetz) to 30% (Rager); that's a dirty great big range. So who's right, and what's their evidence? I agree with the responses that counsel a trial and error approach, I just want to see if there is some good basis for choosing a % utilization.

What do professional brewers do? Get the AA content measured? Beyond my means...

Click to expand...

Well that's just it isn't it. It is all about perception, no? As you know you can make some styles taste far too hoppy on less hops than another. So in a nutshell that kind of defeats the whole 'bitterness'....in other words....the IBU might be right for one style but the same IBU would be way too high for say a wheat so, it may be the same measured IBU but this does not account for perception! My personal feelings (I use the calculations that come from Palmer's book...not sure which one it is) but for my brews I have been using those and tuning my recipes to the results generated from those calculations. I think this will be a mysterious area of brewing and beer appreciation in general for a long time to come.

I guess what I am getting at is that although the equations are time and gravity dependent, there is still another piece to the puzzle. The way some flavors and profiles dominate the palate can create interesting effects. I tend to wonder if using the theoretical FG based on mash profile might not be an area to explore for tweaking the equations.

I have been thinking about the various IBU formulas lately and did some limited Internet research. As it turns out, Raeger, Tinseh and Garetz are home brewers which access to the necessary lab equipment and were so kind to run experiments regarding hop utilization for home brewing. Though there has also been some research done in the commercial world. But in the commercial brewing world, were the same beer is brewed over and over, hop utilization will be determined mainly by pilot brews.

Home brewers wanted to have something better than that and run experiments to determine the hop utilization that they would get in order to get closer to the IBU target with the first try of a recipe. And these formulas are a great tool as long as you keep in mind how they have been determined and what other factors are affecting the bitterness of the final beer:

- age of the hops (currently I'm not sure if we buy 2005 or 2006 hops since the bags don't indicate this)
- boil pH (the higher the pH the better the utilization though the bitterness from high pH boils has been reported as more harsh)
- vigor of boil (you can keep this constant by aiming for a constant boil-off rate)
- amount of time the wort remains hot after flame-out (isomerization does also happen w/o the movement of a boil as long as the wort is hot enough)
- hot break (you should add the hops after the initial hot-break. If you do it before an uncertain amount of alpha acids may get lost in the break material)
- fermentation (Narziss reports that about 30% of iso alpha acids are lost in the yeast trub)
- filtration, fining (this will filter or precipitate bitterness)
- bittering compounds other than hops (roasted grains, beta acids ...)
- and a lot more.

I know that the Tinseth numbers are for wort boiling only and that they don't account for IBU loss during fermentation. The are also for a wort that is cooled immediately after flame-out.

What does that mean to us. If you brew the recipe the for the first time, adjust your bittering hops to target the calculated IBUs indicated by the recipe. You can choose any of the formulas for this. Then taste the beer and adjust the bittering hops according to taste while keeping the rest of the recipe/process pretty much the same. After a while you will get to know your system and what calculated IBUs to aim for to get the bitterness where you want it. I brew my APA with a calculated IBU level of 25, but friends told me that the beer tastes more like 30-35 IBU.

Kai

Thanks Kai. I always like reading your responses.

I brewed the SNPA clone, using an online IBU calculator (Rooftop, I think) and calculated the hop rates based on a target of 37 IBU. Double checked against the long thread on that other forum, by going back to HBUs, and was close enough to start out. Tasted the chilled wort, and it was very bitter, but not harsh, so I'm looking forward to tasting the beer when I rack into secondary, which won't be long given the activity of the Safale S-56 I used.

Thanks for your opinions and insight.