full 5 gallon boil adjustments?

[turfguy1969]

I have been doing extract kits following the recipe word for word. I recently added a 10 gallon pot and would like to boil a full 5 gallon extact kit. I read somewhere here that adjustments should be made for the amount of hops when boiling a larger amount of wort. Where would I find calculations to determine the amount of hops needed.

one mix wanted a half ounce of hallertau at start, and a half ounce at 45 minutes in a 2.5 gallon boil. If I boil 5 gallons do i need more or less hops typically? bittering and aromatic?

Are boiling times the same as well?

thanks

 

[Yooper]

The boiling times for the hops are the same, but you reduce the amount of hops needed due to better utilization by boiling a lower gravity wort.

The easiest way to figure it out is to use some brewing software, like Beersmith. Put in the regular recipe and see what the IBUs come to. Then just switch it (by changing equipment at the top of the page) and see those IBUs. Adjust the bittering addition down until they match. I hope this makes sense- it's really super easy to do in Beersmith, but tough to explain how to do it. Otherwise, I don't think it's a strict "20%" reduction thing, but that might be close.

 

[turfguy1969]

thanks yoop! good luck in the football tourney