hopstand and IBUs

[Iliff Avenue Brewhouse]

I recently have been experimenting with hopstands and noticing that the beers feel a lot more bitter than the calculations would suggest. It seems that is because I'm not accounting for the kettle hop additions continuing to contribute bitterness during the hopstand. I see that option now in the recipe builder. Has that been my main error?

 

[J A]

Yes...
You have to make an estimate based on your observations but you need to account for extra IBUs in the hopstand and whirlpool additions. Also, the flame-out additions left in during whirlpool or cooling are adding some IBUs, too.

 

[Iliff Avenue Brewhouse]

Yes...
You have to make an estimate based on your observations but you need to account for extra IBUs in the hopstand and whirlpool additions. Also, the flame-out additions left in during whirlpool or cooling are adding some IBUs, too.

I think I figured it out and adjust calculations manually. The "no chill" option in the recipe builder doesn't work how I would expect.

My last pale ale was calculated for about 34 IBU however it tastes a lot more bitter. After coming back to revisit, it looks like it's actually closer to 55 IBU which makes sense.

 

[J A]

My last pale ale was calculated for about 34 IBU however it tastes a lot more bitter. After coming back to revisit, it looks like it's actually closer to 55 IBU which makes sense.

I had to do some taste-testing comparisons with IPAs of "known" bitterness to reverse-engineer my settings and come up with a good estimate of the IBU contribution from whirlpool.

 

[Iliff Avenue Brewhouse]

I had to do some taste-testing comparisons with IPAs of "known" bitterness to reverse-engineer my settings and come up with a good estimate of the IBU contribution from whirlpool.

That’s exactly where I’m at. Starting to come together. Totally neglected the extra ibus from kettle additions which changes everything.

 

[J A]

I find that there's a different sensation from the IBUs delivered from the 60 minute boil addition and the IBUs extracted from the whirlpool. The extra bitterness is definitely there but it's smoother, somehow, and doesn't linger the same way.

 

[Bubba Wade]

Keep in mind that hop isomerization will continue until temperature is below about 180 deg F. If you delay between flameout and chilling, late addition hops may add more bitterness than planned. A delay won’t really affect 60 minute additions as they are pretty close to being fully converted.

 

[Iliff Avenue Brewhouse]

I find that there's a different sensation from the IBUs delivered from the 60 minute boil addition and the IBUs extracted from the whirlpool. The extra bitterness is definitely there but it's smoother, somehow, and doesn't linger the same way.

definitely. When I tasted the beer that I thought was 34 ibus I was kind of shocked. Because I was tasting ipa bitterness almost. I have it on with an ipa that is “67” ibus and it’s a completely different experience.

Keep in mind that hop isomerization will continue until temperature is below about 180 deg F. If you delay between flameout and chilling, late addition hops may add more bitterness than planned. A delay won’t really affect 60 minute additions as they are pretty close to being fully converted.

For beers like this I’m referring to no bittering additions. First one at 5 minutes, then flameout for hopstand for 20, and dry hop.

 

[Mark Farrall]

And, depending on how bitter the beer is, you'll get some bitterness from the dry hop. A couple of compounds in the hops don't need heat to impart bitterness. Though if you were fairly bitter before the dry hop, the hops will actually absorb some of your isomerised alpha acids, while still imparting the other bitter compounds (beta acids and something else I can't remember, oxidised hydrocarbons?) and the beer will end up less bitter from a sensory and IBU assay point of view.

I'm pretty sure none of the IBU functions we use for predictions included modelling for hop additions at the end of the boil, and certainly not steeping hops.

 

[J A]

'm pretty sure none of the IBU functions we use for predictions included modelling for hop additions at the end of the boil, and certainly not steeping hops.

There are utilization rate boxes on the various additions but the interaction with time, temperature and percentage inputs ranges from confusing to abjectly dysfunctional. You have to jigger the inputs a little to get a consistent estimate