7 replies to this topic

[stellarbrew]

I brewed a Pilsner a few months ago that came out far more bitter than what my calculated IBUs seemed to predict. In the past, I have used the same Tinseth calculations for many batches, with very predictable results. I used Tettnang hop pellets from the same bag on several other beers, and the bitterness seemed spot on with what I calculated in those cases. So I don't the published AA% are off. I have been scratching my head trying to figure out why the Pilsner tastes more like 50 IBUs than the calculated 37 IBUs. I went back over my notes for that batch and recalled that I did something different than I usually do. Being my first Pilsner, I was trying to be extra careful to be sure that I ended up with clear beer. To that end, I carefully skimmed all the hot break protein foam off the top as it formed. It seems that I have read somewhere that hop utilization is inhibited by the hot break protein, proportionately to how much is present. So I'm wondering if I inadvertantly increased my hop utilization by skimming off all that protein. I can't seem to find anything to corroborate what I think I read. What do you think? Could my theory be valid, or should I look to something else as the cause?

Edited by stellarbrew, 14 September 2009 - 10:29 AM.

[djinkc]

Yeah, I have heard about that too. I've skimmed and not skimmed - no perveivable difference. Besides that hot break will continue to form throughout the boil. And FWH additions sit through all the break formation.I listened to a podcast that John Palmer did after attending a conference. He felt that this is real, that the break associated with increased gravity is the cuplrit rather than simply the increased gravity. However he summed it up to something like this "there's a lot of sharks in the ocean but most never get bit). I would look elsewhere, maybe a mismeasurement......

[3rd party JKor]

Were you using the dregs of the bag? I understand the 'hop dust' tends to have a higher concentration of oils/acids, or maybe it's that they have higher utilization. Something like that anyway.

[stellarbrew]

I guess I can't rule out a mismeasurement... if I did, I'll never be able to confirm it.I wasn't aware the dregs of a bag of hops pack a bigger punch. It might be possible I had some of that hop dust in the mix, but I'm not sure.When I have an undesirable result in a beer I brew, I always try to figure out what happened so I don't make the same mistake again. I guess this is one of those cases where I won't know for sure.

[MtnBrewer]

If it happens again under similar circumstances (namely when you skim) then you might have the confirmation you're looking for. I tend to agree with DJ that there wouldn't be enough hot break removal from skimming to make much of a difference. But I admit that it's possible.

[stellarbrew]

If it happens again under similar circumstances (namely when you skim) then you might have the confirmation you're looking for.

That's true, but I'll probably be hesitant to skim again, for fear (founded or unfounded) of screwing up a batch. Next go round with a Pilsner, I'll probably compensate on every possible level I can think of to keep the same problem from recurring. Not scientifically rigorous, but I hate to sacrifice another batch in the name of science.

[3rd party JKor]

That's true, but I'll probably be hesitant to skim again, for fear (founded or unfounded) of screwing up a batch. Next go round with a Pilsner, I'll probably compensate on every possible level I can think of to keep the same problem from recurring. Not scientifically rigorous, but I hate to sacrifice another batch in the name of science.

If you consider the current batch of Pils "screwed up", brew up a low IBU batch and blend it with the high bitterness batch.

[MtnBrewer]

That's true, but I'll probably be hesitant to skim again, for fear (founded or unfounded) of screwing up a batch. Next go round with a Pilsner, I'll probably compensate on every possible level I can think of to keep the same problem from recurring. Not scientifically rigorous, but I hate to sacrifice another batch in the name of science.

Well then if it happens when you're not skimming, you still learn something. There's win either way!