[gmac]

I'm making a lager today and I want to boil for 90 mins but I had a mental lapse and added my hops at the start of the boil instead of letting it boil for 30 first.  What can I expect from this?  Does the increased boil mean a bit more bitterness or is there some detriment after a certain period of time? 

I only added 1 oz of Hallertau at 4.3% so I don't really care if it is a touch more bitter, I just don't want to lose anything if over-boiling is a problem.
Thanks

[chezteth]

You will get more bitterness due to the longer boil. Boiling hops for longer than 90min can bring out some vegetal notes that would be undesirable.  I think you should be fine.

Happy brewing,
Brandon

[hopfenundmalz]

You will get more bitterness due to the longer boil. Boiling hops for longer than 90min can bring out some vegetal notes that would be undesirable.  I think you should be fine.

Happy brewing,
Brandon

This is true.  The amount of bitterness is reaching diminishing returns after 60 min, so not much more is gained.  Some say that moving the additions later in the boil reduces the vegital flavors, and gives a less harsh bitterness.

One other thing is that you start to get a reversal of the isomerization process at around 90 minutes, and you are making more harsh tasting compounds. 

[blatz]

One other thing is that you start to get a reversal of the isomerization process at around 90 minutes, and you are making more harsh tasting compounds. 

but what if you first wort hopped a wort that was boiled for 90 minutes.  do you think the same would hold true?

[denny]

One other thing is that you start to get a reversal of the isomerization process at around 90 minutes, and you are making more harsh tasting compounds. 

but what if you first wort hopped a wort that was boiled for 90 minutes.  do you think the same would hold true?

Not that I've experienced.

[hopfenundmalz]

One other thing is that you start to get a reversal of the isomerization process at around 90 minutes, and you are making more harsh tasting compounds. 

but what if you first wort hopped a wort that was boiled for 90 minutes.  do you think the same would hold true?

It starts to happen with some magnitude at around 90 minutes.  So don't go longer, as the iso-AA forms up to 90 min, and once you have gotten to the point that not much more is forming, then the breakdown starts to be a negative.  George Fix called the compounds Anti-iso-AA or something like that.

[blatz]

Not that I've experienced.

me neither.  which is why I was asking since perhaps I missed something.  with lagers (and thus noble hops) lately i've become very happy with moving the 60min addition to FWH only.  for hoppier styles like pils, I'll of course also have late hops.

I just was thinking about the longer exposure and was curious what other people's experiences led them to.

[Thirsty_Monk]

To my experience I do Magnum 60 min only. Longer boil gives me hars bitterness. On the other hand Saaz was just fine with 90 min boil. It might be hop variety dependent.