60 vs 90 min boil

Hey guys, kind of a noobie question, but why is there a 30 minute difference in boil times for certain recipes? I know that certain base malts require longer boiling time - like pils for instance, but I’ve also seen a 90 min boil be required for stouts and other styles. Why is that? And if I’m brewing certain styles, should I be changing the boiling times?

90 will darken the wort, called a Malliard reaction and give a more malty flavor. Not something you want in a Pilsner. It also gets better hop isomerization giving you better bittering.

With extract you can actually boil the hops by themselves then add the extract at the end for a short boil so it does not darken. I did one last year that I never even got the extract up to a boil after 60 with just the hops and steeped specialty grains. Turned out great.

With todays malts there’s really no reason to do a 90 minute boil. They don’t require it. I’ve done 60 and 90 minute boils with 100% pilsner malt and noticed no difference other than a little darker color.

Then there short and shoddy to look at… Sneezles61

In addition it can be used to increase your OG. But if it’s solely for DMS skip the 90 min boil. If you’re really really worried about it do 75 which with today’s malts is PLENTY.