[dmtaylor]

I realize that the IBU number itself is based on each brewery and a correlation to what the drinker perceives. My question pertains to calculation of that number.

When I calculate in BeerSmith I get a wildly different number that in Brewer’s Friend.  I believe they both use Tinseth’s calculation but how are they 15 points apart? (I was not exact in my duplication but close enough to make the point):

Multiple things going on here:

1) Volumes -- This is the biggest one.  Your first entry in Brewer's Friend says 6.5 gallons, versus BeerSmith says 5.5 gallons.  That will have a huge effect.

2) Late hop additions in BeerSmith look way off to me.  Should be much lower in single digits, not 10 IBUs each.

3) Are you really using whole hops?  In Brewer's Friend you specify whole hops.  Not sure about what you put into BeerSmith.  But make sure those are consistent between the two softwares.

If whole hops and 6.5 gallons, I calculate about 26 IBUs.  Otherwise.... well, it depends on all 3 of those things above.

[Robert]

I brew 6.5 gallon batches with whole cone hops and have evolved my own simplified method for making IBU estimates (my palate tells my my system has  been dialed in to pretty darn good enough.)  With your recipe I would anticipate about 22 IBU in wort, leaving about 16 IBU in beer.   That's a little lower than BF, but way closer than BS.  Something just looks fishy to me with BS's numbers.  I know that doesn't answer your question, but it might help you evaluate the results.

[BrewBama]

I agree with both of you: sumthin ain’t right. I also think at those quantities the result should be much lower than BS tells me as well which is why I poked the numbers in Brewer’s Friend to compare them.

Dave, I am using whole hops. I plan 6.5 post boil and 5.5 in the fermenter.

I want 10 IBU(s) each of the Aroma and Flavor hops.


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[Robert]

The utilizations in BF look very plausible to me, with the caveat that you might get a little  bit less with the 10 minute addition, but that's quibbling over numbers we can't be exact about anyway.  And with whole cone, I completely ignore the contribution of a 1 minute addition.   If I were you, I'd just manipulate your recipe in BF until you get the values you're looking for.   It will be closer than your palate's ability to distinguish,  I bet.

[BrewBama]

The utilizations in BF look very plausible to me, with the caveat that you might get a little  bit less with the 10 minute addition, but that's quibbling over numbers we can't be exact about anyway.  And with whole cone, I completely ignore the contribution of a 1 minute addition.   If I were you, I'd just manipulate your recipe in BF until you get the values you're looking for.   It will be closer than your palate's ability to distinguish,  I bet.

I am one step ahead of you. This is what I ended up with:




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[BrewBama]

Ok. I found it. Some ‘IBU carry over’ box was checked. It’s within reason now.




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[Robert]

Ok. I found it. Some ‘IBU carry over’ box was checked. It’s within reason now.




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That's still showing 5.5 gallons for the volume... or does that mean volume to the fermenter?  But but on another note, your hop schedule is starting to look pretty good.  I'm no longer a fan of super late additions.  Maybe using whole cone and gentle boils helps, but I get more flavor and aroma pushing it back from the end.

[dmtaylor]

I agree with both of you: sumthin ain’t right. I also think at those quantities the result should be much lower than BS tells me as well which is why I poked the numbers in Brewer’s Friend to compare them.

Dave, I am using whole hops. I plan 6.5 post boil and 5.5 in the fermenter.

I want 10 IBU(s) each of the Aroma and Flavor hops.

Your batch size is clearly 6.5 gallons then, regardless of how much you actually end up with in the fermenter.  Why the waste of a gallon anyway?  Is that for lost wort due to using all whole hops?

[Robert]

I agree with both of you: sumthin ain’t right. I also think at those quantities the result should be much lower than BS tells me as well which is why I poked the numbers in Brewer’s Friend to compare them.

Dave, I am using whole hops. I plan 6.5 post boil and 5.5 in the fermenter.

I want 10 IBU(s) each of the Aroma and Flavor hops.

Your batch size is clearly 6.5 gallons then, regardless of how much you actually end up with in the fermenter.  Why the waste of a gallon anyway?  Is that for lost wort due to using all whole hops?

Good question but it would be the other way around.  I used to lose at least a gallon when using pellets.  With whole cone it's less than a quart.  One (trivial) reason I went back.  But what's a gallon if you're happy with your process and its predictable.

[BrewBama]

That’s carry over from using pellets. I’ve only used whole cone for two brews now and as I gain experience over the summer I’ll dial that in.


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[Robert]

That’s carry over from using pellets. I’ve only used whole cone for two brews now and as I gain experience over the summer I’ll dial that in.


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Had the same problem when I switched back.  I was over brewing for a while.  Better than coming up short!