adding hops

[tickle]

right may sound stupid to ask this
when adding hops
at the start of say 90min boil do you add the hops at this point or when you have the time left to add the first hops
some hops say boil for 60min then some say boil for 10 min
so do you add the first when you have 60min boiling left and so on
till all hops are in

[Kev888]

The times given for hop additions are the times remaining until the end of the boil. So yes add 10 minute hops 10minutes before you turn the boiler off and so on.

Hops that are boiled for longer have more bitterness extracted, but also more time for the flavour and especially the aroma to get boiled away. So its normal to stagger the additions in order to get the best of both worlds (in beer styles that want both). Typically highly bitter hops are used for the full boil, and more flavoursome/aromatic types later - although some hop types are dual function and are used for either.

EDIT: Sometimes you may see 80c steeps recommended; these are added once the wort in the boiler has cooled to 80c. The idea is that below 80c far less bitterness is extracted and more aroma is preserved. There are also 'dry' hops which are added to the fermenter or the keg, mainly for aroma purposes.

[tickle]

many thanks for your reply

[Kev888]

No probs. I should also mention that 60 min hops are generally still counted as full-boil bittering hops, its just that some people only boil for 60mins. There isn't actually much difference in utilisation between 60mins and 90mins, just a tiny bit more bitterness is gained for the extra half hour. You may get (for example) about 32 bitterness units instead of 30, and theres so much approximation in these things that it doesn't normally matter much if you put 60mins hops in at 90mins or visa versa.

The later hops used for flavour and aroma are much more time dependent.