Sierra Nevada Pale Ale IBU problems

[Belter]

Hey! I've finally acquired enough kit to be able to start AG brewing. After asking advice previous I have decided on the Sierra Nevada Pale ale clone listed on Malt Miller (http://themaltmiller.co.uk/index.php?_a=viewCat&catId=9). I thought I'd try typing the recipe into Beer Alchemy to keep track of what I'm brewing and to see what it came up with. Turns out to get the required IBU recommended in the recipe (70.00 gm Cascade (1 min) Hops 9.7 IBU Seventy grams of Cascade hops are added to the boil with just 1 minute to go) at an Alpha Acid of 7.9% it says that I need 273g of Cascade? Has there been a misprint? I realise that their alpha acids could be different as to the Cascade I'm using (2011 crop) but surely they don't range that much?

Am I doing something obviously completely wrong? Or is that a misprint?

I've uploaded the recipe I input into Brew Alchemy here: http://depositfiles.com/files/t93hf7zt0

Cheers

Lee

 

[BIGJIM72]

Have another read of the recipe-it calls for 30 grams of Northern Brewer for 60 mins-there's your bitterness right there.

 

[Belter]

Yeah I understand that. That part of the recipe I don't have a problem with. It's the next part. To obtain the req'd IBU that is called for for that portion of the recipe it doesn't add up.

 

[jampot]

Add the 70g cascade with 6 mins to go not 1 min to obtain just under 10 ibu's

 

[rich27500]

I made this as one of my first after returning to AG and it was lovely. So nice that when I discovered another bottle when I thought it was all gone I did a little dance!

 

[Belter]

Ah thank you Jampot. That's one thing I hadn't thought of, increasing the time. This will be my first all grain so the obvious answer totally escaped me.