IBU question

[jonmohno]

Is hop utilazation affected by a boil with a small amout of mashed grain(2 gallon batch)as opposed to boiling with a larger amount of dme at the beginning of the boil than the end.\
For instance i mashed some grains and if i didnt get good efficency will it effect a sixty min hop boil for ibu's? Because i added dme at last 10 min of boil to not carmalize so much for a lighter color.
Do you get more bitterness with less sugars or more? this is basically what im asking. Because i had probably 1/4 malted sugars at beginning.I mashed about 25%(TOATAL- NOT EFFICENCY) of barley sugar at the beginning AND 75% of barley(last 10 min added the dme) was boiled at the last 10.

 

[vitrael]

If you have a lower efficiency during mash, you have a lower starting gravity, so your utilization will be higher and your beer will be more bitter. I doubt that you will notice if it was a small difference in utilization.

Correct me if I'm wrong. I'm all theory and no practice.

http://www.howtobrew.com/section1/chapter5-5.html

 

[jonmohno]

SO your saying if there is less barley sugar at beginning of hop boil that will make it more bitter as opposed to a greater grain efficency and adding all my dme at the beginning of the boil?
So most of my fermentables were added at the end of my boil, this would mean the ibu's would be higher because it was boiled with a small amount of barley sugar fermentables for my bittering hops at the first 45 min of the boil?

 

[vitrael]

Yes. If you think about it in a more common situation, imagine utilization in a 5G boil vs a 2.5G boil that will be mixed in the fermenter with 2.5G of water.

The utilization is better in the 5G boil because the gravity of the boil is lower.

It stands to reason that because the gravity of your boil will be relatively low until you add your fermentables near the end, you will be getting better hop utilization than had you added them earlier, making your beer more bitter.

 

[jonmohno]

So this is like a loophole to make someone a cheapass to get the most bittering with the littlest amount of hops? My brew calculator did not account for this i wonder if i doubled the ibu's on this. I only intended to get a pale color because the light dme i have is actually a light amber but i was going for a pale or golden color.thats why i added last ten and the amount of grains i steeped was pretty low compared to the amount of dme like i said it was about 25% mash@ 45 min boil.75% dme at last 10 min. Fermentables wise-roughly.

 

[vitrael]

You would have to be getting less than 50% utilization to double your finished IBUs.

You cannot have more than 100% utilization and you will only ever get as much bittering as you can get out of 100% of the alpha acids in your hops. So really I don't think you will notice a big difference unless your utilization in previous batches was very low.

 

[jonmohno]

oh,no. ive been getting 85-95 efficency for mash on brew calculators.I basically used the partial mash link on this site. did 60 min steep@155 then 10 min sparge soak @160.I guess i nailed efficency on grain conversion, hopefully.
But what im sayin is i only used 25% of my fermentables to do my hop bittering boil for 45 min. then added the rest of dme@ last 10 min along with my aroma hops.