Lost with IBU's

[Doingatun]

Hi All,

I’ve just brewed Broadsword recipe out of Marc Ollossn’s Real Ales

Fuggles Hops (3.3%AA) 136g - start of 90min boil

Styrian Goldings (4%AA) 27g - last 15mins

36 IBU

23L

Thinking I’ve used a lot of hops and having a play with Promash (orignal default settings) when I put the hops in it gives nearly 68 IBU’s, how can there be such a big difference, when I use pencil and paper I get 52 IBU’s for the boil hops, think I’ve lost the plot what am I doing wrong .

[mysterio]

You're doing nothing wrong, IBUs are not an exact science and there are several different calculations for working them out. A lot of different factors come into play - not just the AA% content and boil time, but the strength of the boil, the wort composition, shape of kettle, etc...

The best thing, and what most of us do, is pick one calculation and stick with it. If you find your beer too bitter at 68IBUs, you know to go for a lower value next time, and vice versa. Take good notes.

[Doingatun]

Thanks for the reply Mysterio…I was panicing thinking I may have over hoped for my liking.

I don't really understand the hop utilisation settings in Promash.

Cheers

[Doingatun]

Have you checked down the sofa, they might be there

(btw posts have been dispatched to me so you should haver them soon )

Very funny

Many thanks I'm looking forward to there arrival and so will the Broadsword.

[David Edge]

IBUs are not an exact science and there are several different calculations for working them out.

True but a difference between 33 and 68 seems more than can be explained away by differences in calculation methods - especially as this is a mid-range beer. I think the big differences are at the extremes. I'd suggest a pm to MO to get a view on this. Do Mark's recipes give an assumed AA% for the hops?

I always recalculate other peoples' recipes in Promash before I use them.

[bitter_dave]

The default on promash gives me 42 IBUs when I put these figures in

Personally I don't think the hopping levels look particuarly huge given the low AAUs.

Edit - my default was set to 25 litres... still, 68 IBUs seems very high

[prolix]

I get the 68 ibu's from my calculation as well but that just means you need to leave it an extra month or so to mellow if it is too bitter. I brewed an IPA at 87 (got wrong AA%) by mistake it was like sucking lemons at first but after 4 months was sublime. Now I have 8 working cornies (thanks DaaB still owe you dosh for that) will have a go at brewing more like it as can store them.

[Doingatun]

What do Promash users do?

After getting confused with high IBU’s and wanting a acceptable base to start from I entered a few of Graham Wheeler’s 23 litre recipes I’ve brewed using his 20% utilisation and average AA’s into Promash…fiddled about, the only way I can get IBU levels as predicted in the recipe and DaaB’s Hop Calculator was to go into > Options > System Setting > Hop Calculations & Storage and adjust Kettle Size Hop Utilisation Scale Factor (it says Under 75 Litres use 1) I’ve set this to 0.7 and get somewhere near.

Is this the correct method to adjust Promash Hop Utilisation, 1 or 0.7 what? I was expecting to be able to enter a figure between 20 – 35% in a box.

[Vossy1]

DAT, I've done this brew a few times now and like you, I did the original true to the book. If you like your hops you'll be very impressed with this brew when you first try it. IMO it's as good if not better than the Styrian Stunner.

FWIW, I've just done this recipe and lowered the IBU to those stated in the book ie, 36, as Mrs V1 doesn't like bitter beers.

The result is a beer I don't like. It's not as fresh and crisp in flavour as the higher IBU'd beer and I would describe it as lame taste wise

Like Prolix saiys if it's too bitter, just let it mellow for a bit. I found my 1st corny a bit harsh bitterness wise but by the time I got to the second it was ruddy lovely

[Doingatun]

Thank for the replies/advice.

Learning all the time…beginning to understand now. I thought my Broadsword would turn out to be undrinkable surprised by the high level of bitterness when I tried a sample after kegging .

Luckily at the moment brewing is exceeding consumption so should be able to mature and mellow a tad, looking forward to tasting the changes.

Cheers