Can I extend my boil until I hit proper gravity?

[brevity]

I have an interesting situation. I usually do a partial boil/partial mash technique for my 5 gallon recipes (my pot isn't big enough for full boils, and a little extract makes up for missing gravity). But my wife recently came back from the brew store with ingredients for a 5 gallon all-grain batch, no extract, a little too much grain to mash in my 5 gallon cooler. My question is, if the recipe calls for a 90 minute boil and a single 60 minute hop addition, is there any harm in boiling the wort for an extra 30 minutes or so to further concentrate it?

So basically it would look something like:
Fill pot with first runnings and boil 30 minutes
Top up pot with remainder of mash runnings and continue boil for another 30 minutes
Proceed with hop addition and continue boil for another 60 minutes

What negative effect does increased boil duration have prior to adding hops or adjucts?

 

[wyoast]

Sure go for it, Ive done it before and I know that many others have as well.. As long as you've done your water calculations correctly and know how much longer you will need to boil to hit the mark..let er rip. It would be beneficial if you had a refractometer to check your gravity along the way but if you don't..oh well. I would say as long as you know your equipment and what it will take, trust your instincts and brew away!!
:rockin:

 

[jbaysurfer]

Yeah, that's the way to do it, BEFORE the first hop addition. I've done it at the end too within reason, but you're going to increase your IBUs doing it that way. I've only done that on DIPAS and other beers that were so hoppy I figured nobody would notice a few more IBUs.

 

[CadillacAndy]

I do this with almost every beer I've made over the past couple of months. My efficiency has been all over the place and my water volume has been slightly over after changing around some hoses and equipment.

 

[brevity]

Thanks all!

 

[MuddyCreek]

I built a spreadsheet that calculates how much I will need to boil off in order to hit my target OG based on the pre-boil gravity of the wort.

I'll boil that stuff for DAYS! I like it hoppy.

 

[johngaltsmotor]

The only impact of a longer (pre-hop) boil on flavor will be a bit more carmelization of the sugars - not enough to change style categories but professionals may be able to notice.
As with others, I've used it to make up for too fast of a sparge and a low pre-boil gravity and high pre-boil volume.

 

[Denny]

Yeah, that's the way to do it, BEFORE the first hop addition. I've done it at the end too within reason, but you're going to increase your IBUs doing it that way. I've only done that on DIPAS and other beers that were so hoppy I figured nobody would notice a few more IBUs.

There's so little increase in hop utilization past 60 min. that I've found that it doesn't really matter.

 

[Denny]

The only impact of a longer (pre-hop) boil on flavor will be a bit more carmelization of the sugars - not enough to change style categories but professionals may be able to notice.
As with others, I've used it to make up for too fast of a sparge and a low pre-boil gravity and high pre-boil volume.

Kettle temps don't get hot enough to caramelize sugars.

 

[jbaysurfer]

There's so little increase in hop utilization past 60 min. that I've found that it doesn't really matter.

True, but I think you'll see a substantial increase in the IBU output for all other hop additions. IE: you boil an extra 10 minutes at the end, and your 20 minute additions get boiled for 30 minutes. Your 5 minute addition maps out to the equivalent ibus of a 15 minute addition and so on...

 

[CadillacAndy]

True, but I think you'll see a substantial increase in the IBU output for all other hop additions. IE: you boil an extra 10 minutes at the end, and your 20 minute additions get boiled for 30 minutes. Your 5 minute addition maps out to the equivalent ibus of a 15 minute addition and so on...

Yeah - that will make a big difference. If you realize your gravity is off, just extend the boil without adding the late hops until you're where you need to be. So if at 30 mins you realize you're a little low on your gravity, boil for 10-15 mins and check again, then start your timer over at 30mins instead of adding your 30 min addition and then setting the timer to 40 mins.

 

[Denny]

True, but I think you'll see a substantial increase in the IBU output for all other hop additions. IE: you boil an extra 10 minutes at the end, and your 20 minute additions get boiled for 30 minutes. Your 5 minute addition maps out to the equivalent ibus of a 15 minute addition and so on...

Yeah, that's true. What I do is check gravity before I start late (like 20 min. or less) additions and continue the boil at that point if I'm not on target.

 

[stpug]

If you find yourself pretty low at the end of boil then you can always use a pound or two of dme/lme to reach your final gravity, fwiw.

 

[jbsg02]

Not the answer to your question, but my efficiency has been better and more consistent since I began performing a mash out.