Extended boil time grain bill adjustments

[stadtbrau]

I've got a saison I'm planning to brew tomorrow and I will be doing a 90 min mash and a 2 hr boil. Curious if I need to lower my mash efficiency or my boil off in my calculations to avoid over sparging. I've got my calculations at 75% efficiency although it's generally a bit higher than that and my boil off @ 1.5 gal per hour. The pre boil volume just sounds like a lot for the amount of grain to get to 1.055 after 2 hrs.
I could set the boil off lower and just throttle back for a less vigorous boil.
What do you guys generally do for long boil times. Or should I just be adding water after sparge?
I'm fly sparging by the way.
Thanks for any suggestions. Hopefully I'm over thinking this

 

[smyrnaquince]

I increase the mash water volume to allow for the additional boil-off. No changes to sparge volume needed.

If you are gong to throttle back your burner, you'll want to try it on a pot of water to figure out what your boil-off rate is at that burner setting/boil intensity.

 

[chickypad]

Why the 2 hr boil? Only reason I can think is to allow more sparge for a really big grainbill or something, but you're talking a 1.055 beer.

 

[stadtbrau]

My grain bill is 100% pilsner malt. I read a thread on the board someplace about a saison DuPont clone and to get some color and flavors into the beer the poster tried a 2 hr boil after a 90 min mash and was pleased with the results. I thought it was interesting and wanted to give it a try.

 

[stadtbrau]

Just finished sparge and my efficiency was 90%!! I did my calculations for 75%. This is a new system and I haven't got my efficiency dialed in. What should I do? Boil for 2 hrs still? I have 8.25 gal of 1.044 wort almost to a boil. This wort was supposed to be 1.055 after 2 hrs and planning for 1.25 gal per hour boil off. Any help is appreciated!

 

[stadtbrau]

As a side note. What should I set my efficiency to next weekend? This beer was a 90 min mash at 147 degrees. Is that part off the reason my mash efficiency came out so high?

 

[smyrnaquince]

The large sparge helped your efficiency.