Hollywood IPA

[MightyMouth]

I was thinking of doing this next weekend but looking at the recipe one the CBA website it doesnt give the AA% for the hops, it only gives the Total IBU. So my question is is the IBU calculated from only the early hops or is it calculated from all the hop additions? If its the latter how does that effect the flavour and aroma if you have to use more or less than the original recipe to equal the recipe IBU?

Recipe copied and pasted from the CBA site

Hollywood IPA 1056 (Ernie Gallagher, 1st Prize Strong Bitter 2007)

Pale Malt 5700g
Crystal Malt 450g
Torrified Wheat 100g

Boiler
*Northdown 35g (80 min)
*Cascade 20g (80 min)
Cascade 30g (20 min)
Irish Moss 10g (15 min)
Cascade 30g (10 min)
**Cascade 30g (0 min)

Primary Fermenter
Safale US-05 (US-56)

Secondary Fermenter
Cascade 15g

Mash Time 90 min
Mash Temp 67 C
Sparge Temp 77 C
Boil Time 90 min

Original Gravity 1056
Final Gravity 1012
IBU 45
ABV 5.9%
Final volume 23 litres

* First batch of hops added 10 mins into the boil.
** Final batch of hops added after cooling had begun. At around 75C.
Normally Im a "first wort hopper". But this time I added the hops well after the boil had begun. The last batch of hops was added when the wort was cooled to around 70C.
The reason for highlighting these points is because this was the first time I tried them! The aim in both cases was to help retain the hop flavour and aroma - which Im happy to report worked very well!

[MightyMouth]

Ok, so I guess I will just decrease all the hops during the boil to get down to the correct IBU and leave the later additions alone hopefully to keep as much flavour and aroma as possible.

So now I have the following

Pale Malt 5700g
Crystal Malt 450g
Torrified Wheat 100g

Boiler
*Northdown 25g (80 min) 8%AA
*Cascade 20g (80 min) 7%AA
Cascade 20g (20 min) 7%AA
Irish Moss 10g (15 min)
Cascade 20g (10 min) 7%AA
**Cascade 30g (0 min) 7%AA

Primary Fermenter
Safale US-05 (US-56)

Secondary Fermenter
Cascade 15g 7%AA

Mash Time 90 min
Mash Temp 67 C
Sparge Temp 77 C
Boil Time 90 min

This will leave an IBU of about 48 which is a little higher than the original recipe but within the style guidelines. Any thoughts?

[stevezx7r]

As far as I know, IBU's are calculated from any hops which get boiled as this is when they release their bittering compounds. I suppose even adding hops at the end (or at 80C) would add to the bitterness just not as much as if they were boiled.

[MightyMouth]

I sort of understood that all hops added at any time during the boil contribute to the bitterness, my question is am I better off reducing the 80 minute hops only until I get the correct IBU or should I try to reduce all the hops a little. It seems to me I should just reduce the 80 minute hops to get down to the required IBU as this will leave more late hops for flavour and aroma but I am just looking for confirmation that this is correct

[stevezx7r]

Or could he use less hops but boil for 90 instead of 80 mins?

As a side question (no hijack intended) Daab, what do the Beta acids contribute to hops? I was under the impression that was where the "strength" of flavour a specific hop could yield. But I could be well off the mark.

[stevezx7r]

The difference in utilisation between 60 and 90 mins is minimal, between 80 and 90 mins it would be negligable.

Any thoughts on the Beta Acids, DaaB?

[stevezx7r]

Yes they add needless confusion, I pretend they don't exist and they don't bother me

Funny, that's what i've been doing since I first read what's on a packet of hops. It's just bugging me to find out now.

Right, google time.

[stevezx7r]

Well, that was quick...thanks to Wikipedia - http://en.wikipedia.org/wiki/Hops


Alpha acids have a mild antibiotic/bacteriostatic effect against Gram-positive bacteria, and favor the exclusive activity of brewing yeast in the fermentation of beer.

Beta acids do not isomerise during the boil of wort, and have a negligible effect on beer flavor. Instead they contribute to beer's bitter aroma, and high beta acid hop varieties are often added at the end of the wort boil for aroma. Beta acids may oxidize into compounds that can give beer off-flavors of rotten vegetables or cooked corn.

Interesting? Or just carry on as we were?

[stevezx7r]

You could be right DaaB but it's nice to know even if it doesn't effect the beer much. Wiki isn't too bad, it is edited regularly so the info is fairly trustworthy, at least as much as anything else on the web