Bittering effect of aroma hops in last 10 mins of boil

[Chemo]

Having been to my friendly local brewery for some Malt yesterday, the brewer gave some hops to try.
Bodicia 5.6% and Nugget 14.2%
As an experiment to see the effect of these very different smelling hops, I plan to do 2 x single hop variety brews based on the landlord recipe.
Does anyone know if there is any calculation about an amount of bitterness released in the aroma hops in 10-15 mins at the end?
I'm pretty sure that some bitterness is released and if I dose both these 50l brews with 50g of aroma hops at the end - the Nugget one is likely to come our more bitter is it not? - thus slightly perverting my experiment.

I suppose I should just do a brew with no hops at the end for comparison - but that would just be boring!

any comments?

[Taf]

Why not put the recipe into Beerengine of something similar. With beer engine anwyay, you can see the IBU's increase with the hop addition.

Cheers,
Billy.

[jmc]

Hi
I second Taf's suggestion

Much easier, and probably more accurate to use Beer Engine rather than try & do the math.

All the best
John

[GrowlingDogBeer]

Beer Engine can be downloaded from Graham Wheelers site here

http://www.practicalbrewing.co.uk/calcu ... eerengine/

[mysterio]

If you're after a rough estimate, then you get about 50% of the 60 minute bittering potential if you boil the hops for 15 minutes. But yes, use one of the free online calculators.

[Chemo]

Well, in fact I AM using beersmith - but it doesn't add to the IBU when you add aroma hops.
I think the 50% rule is probably about right, so I'll reduce it to 30g from 50g on the stronger hop I think

[jmc]

Hi Chemo

I just had a try of Beeer Engine v1.09

Assuming Hop EBU setting not fixed...
If you set hop time to 10 minutes (Flavour hops) and change weight the hop then EBU figure changes.
If you set hop time to 0 minutes (Aroma hops) and change weight the hop then EBU figure does not change.

I assume program uses boil time as part of hop utilisation calc.

I hope that helps
All the best
John

[Gricey]

ISTR you dont get added bitterness from aroma hops (0min/steep), possibly because you dont extract the bittering compounds <80°C? (cant look that up right now...)

[mysterio]

I guess that formula assumes you add your final hops then knock the wort out immediately through a CFC or plate chiller, if you are steeping for half an hour and/or using an IC, you certainly get bitterness extraction.

[WallyBrew]

the link below goes to some experimental results

hop utilisation

Check the boil time in column A against the utilisation result in column N. D19 explains what 0 boil time is

[coatesg]

I guess that formula assumes you add your final hops then knock the wort out immediately through a CFC or plate chiller, if you are steeping for half an hour and/or using an IC, you certainly get bitterness extraction.

Yeah - you get a bit because the hops are added while the wort is still hot. If you use an IC, this won't be much (I can drop 25L from 100C to 80C in a few minutes). If you use a CFC, the contribution may well be a lot more.

[Deebee]

Well, in fact I AM using beersmith - but it doesn't add to the IBU when you add aroma hops.
I think the 50% rule is probably about right, so I'll reduce it to 30g from 50g on the stronger hop I think

Thats because sure aroma hops are considered as steep hops in beer smith. You are actually boiling them for 15, and that will give you ibu numbers.