Adjusting Hop Quantity

[stuart_A]

Hi

I was wondering if it is common to adjust the hop quantums if the alpha assumed in the recipe differs from the alpha of the hops you purchase?

For example, in the recipe im about to follow the Hop schedule is as follows;

Magnum 11% - 23g @ start of boil
Hallertaurer Mittelfruh 5% - 5g @ 5mins
Hallertaurer Mittelfruh 5% - 9g @ turn off

But the hops i have bought have different alpha acid levels
Magnum 12.2% & Hallertaurer 1.5%

So would you use a little less Magnum and quite a bit more Hallertaurer to componsate? Would you maybe only adjust the Magnum as its the bittering hop? and just leave the Hallertaurer as is?

I found a online calculator which suggests, based on the difference in alpha levels, that the following quatums could be used?

Magnum 12.2% - 16g @ start of boil
Hallertaurer Mittelfruh 1.5% - 13g @ 5mins
Hallertaurer Mittelfruh 1.5% - 23g @ turn off

As you can see this is quite a big change from recipe, particularly for the late additions

Also, do any of you make adjustments to the quantum you use if you use pellets instead of leaf etc?

Im probably over thinking this but any opinions would be most interesting

Thanks

 

[TheRedDarren]

Yup, that's the way to do it, adjust the weight depending on the acid content.

 

[dan125]

Agreed - but I wouldn't change the late additions so drastically (if you're wanting the replicate the brew in the recipe closely at any rate) as these are for flavour rather than bittering. By increasing them so much you will change the flavour profile.
I'd be tempted to leave the late additions as per the recipe and just adjust the bittering hops to get to your target IBUs.

 

[stuart_A]

Thanks both.
I will therefore adjust the bittering hops but maintain the late additions at the original quantities

..you learn something new every day, cheers!