Kettle size and hop utilization

[GregR]

Does anyone have exact info on how to account for kettle size when calculating hop utilization?

How to work this in to hop util. calcs?

Thanks!

Greg

[dick murton]

Kettle size has absolutely no direct connection to utilsation. Utilisation is dependant upon, amongst other things, the age of the hops, the time of hop addition, the length of boil, the wort gravity, and perhaps surprisingly, less to do with the vigour of the boil, as long as it is boiling. However, vigorous boils tend to help ensure the entire contents are turned over, and will thus affect utilisation by ensuring even hop and temperature distribution throughout the wort, rather than leaving some dead volumes in the kettle. If you brew at high altitudes, so the boiling point is less than 100 C, then this will also reduce utilisation a little, the guys from the high Rockies probably being amongst the best to advise of the % effect

Cheers

[Øl-sheik]

Deside what IBU you aim for : 1 IBU is 0,1 g alpha acid per hl (100l)

Example: 32 IBU means 64 g in 20hl

Now the hop yield, depending on various factors Dick explained, I just want to add the hop product itself. 90 min conventional boiling should give you a yield around 30 %, when pellets are used. (just a guideline)

meaning in our example 64g = 30% / 213g = 100% , which means you have to add 213 g alpha acids at beginning of boiling.

Let`s assume you use Amarillo 7,9 %, (our 213 g) then add 2700 g of it.

I let you do the transfer from metric into US measurements ;-)

Get the IBU in your finished beer checked and compare with you estimated hop rate, voila the whole secret

[dick murton]

Doh

How stupid of me. I read this as I had explained, not, "how to calculate a hop grist for different wort volumes" Thanks for putting me straight.

Cheers