steeping grain kit boil volume question

I've been doing Brewer's Best kits and just got a MidWest supplies and am getting contradictory information concerning the boil. BB tells me to only boil with 2.5 gallons as hops are measured exactly for this amount and using more will give me more IBUs, or make the taste more bitter. MidWest instructions say to boil as much as possible as that will give you the best tasting brew. Any thoughts? I may just boil more and see what happens.. but don't want to get the taste way out of line.

thx!

This is where some brewing software can come in handy! If you post the recipe, we can run it through some software or you can download a free trial of Beersmith and see it for yourself. Adjusting the boil volume definitely impacts the hops utilization. Sometimes, the difference is pretty insignificant, but sometimes it's a big difference. It depends on the recipe, and whether it was formulated for late extract addition or not. Adding the extract late in the boil usually negates the boil size effects.

I scaled up my last two BB kits to full 6.5 gallon boils and I decided through some answers here that I would just put all the hops into the batches that came with the kits. My first one turned out awesome and my second one is still fermenting but smells great. Do what you like but it is hard for me to believe that 10-20% of .7 to 1 ounces will really make that much of a difference. Now if you are brewing a double IPA and dry hopping it in the secondary you may want to adjust that. I ran both of mine through beersmith and it indicated to cut about 20% of the bittering which equated to about 4 pellets.

Right, good point. and the beer would just become a little more bitter i suppose, which since I like IPAs may not be to big of a deal anyway.