Meantime London Porter

[LiverDance]

Just finished listening to the show and looking forward to trying this one. In the show the brewer mentioned this brew was around 35 IBU's but when I plug the hop additions (22g @75, 24g@10, and 24g@0) in Beersmith I get an IBU of 16.6 using Rager. What gives, were these supppose to be double the given amount?

Thanks,

LD

[Jimmeh]

Just finished listening to the show and looking forward to trying this one. In the show the brewer mentioned this brew was around 35 IBU's but when I plug the hop additions (22g @75, 24g@10, and 24g@0) in Beersmith I get an IBU of 16.6 using Rager. What gives, were these supppose to be double the given amount?

Thanks,

LD

Doing the same batch size?
Same Alpha Acid on the hops?

[LiverDance]

Yes on both, 21.8 Litres and 4.7%AA. Unless they were shooting for a lower IBU??

[Jimmeh]

Ah hang on, I know whats happened.

The brewer from Meatime stated 35ibu's... problem is that it is a measured ibu value. That means they have a lab test the ibu's.
Homebrewers dont get that luxury usually, so we have to rely on basic estimation formulas like Rager, Tinseth etc and they often dont match the same numbers the lab produces. If you listen to the show again, Jamil later comes up with an ibu value that homebrewers can use to match the real thing. Jamil says 18 ibu (rager).

Hope that makes sense.

Cheers

[mookie1010]

Pretty sure it's the utilization from late additions that don't get calculated as contributing as many bu's as they really do.

Does anyone know if the software programs assume that you go from boiling to chilled in a set amount of time?

[biertourist]

Pretty sure it's the utilization from late additions that don't get calculated as contributing as many bu's as they really do.

Does anyone know if the software programs assume that you go from boiling to chilled in a set amount of time?

Great question! I'm looking for the answer, too. I wish the major brewing software packages would give you the ability to input the amount of time that it takes you to chill from boiling at flame out down to yeast pitching temps and have it adjust the IBUs taking that into account.



Adam