**From:**ony@spss.com (Tony Babinec)

**Subject:**homebrew "steam" beer and hopping rate

**Date:**1992-04-23 15:39:33 GMT

`In the last HBD, Bryan Gros described his hopping of a "steam" beer.
Is the homebrew "steam" beer adequately hopped? I'd say that if
it isn't, he didn't miss by much, so relax...
The formula from the Hops Zymurgy issue is:
gram weight of hops to add =
Wort Volume*BU*.001 / (Percent Utilization*Alpha),
and ounce weight of hops = 0.0353*gwh.
In this case, filling in the formula:
gwh = (18.9*40*.001)/(PU*.085).
Percent utilization is a function of the length of boil. The Hop
Zymurgy issue lists percent utilization at 30%, or 0.30, for a one
hour boil. However, you might want to downweight that a little
bit, to take into account hop age, extent to which you attain a
rolling boil, and such. If you assume PU is 0.30, then one hop
addition at one hour before end of boil should be 1.05 ounces of
your Northern Brewers. If you assume PU is 0.25, then one hop
addition at one hour before end of boil should be 1.26 ounces of
your Northern Brewers. Since you split your one ounce addition of
NBs into 0.75 ounces for 60 minutes and 0.25 ounces for 30 minutes,
your bitterness falls a bit short of what it would be if the entire
one ounce were added for an hour, as the above shows that 1.05
ounces would be needed assuming 30% utilization.
If you are concerned that your beer will lack a little in
bitterness, this is all the more reason to dry hop to compensate.
Not that you'd get the same character as if you had boiled, but the
character would certainly be appropriate. Try Northern Brewers or
even Cascades. Although by all reports Anchor doesn't use Cascades
in Steam, I think they're appropriate and it's YOUR beer! Try 1/2 to
1 ounce of Northern Brewers, or 1/2 ounce NB plus 1/2 ounce Cascades.
Doesn't Fred Eckhardt's book show a recent Anchor Steam to be
hopped slightly less than an older one--say, IBU equals 35? If so,
then your hopping is near-target. Let's hope that Anchor doesn't
knock that number down, as Anchor Steam is a world-class beer and
just fine as it is!
The percent utilization ambiguity homebrewers face in practice
helps explain IBU/HBU conversion. If you assume 30% utilization in
a one-hour boil, then
HBU = IBU/4.5
while if you assume 25% utilization in a one-hour boil, then
HBU = IBU/3.8
Hop additions at less than 60 minutes will have a smaller
utilization number. While it appears that hop utilization is not
a linear function of time, you probably won't be far off by
assuming PU for a 30-minute hop addition to be around 13-15%.
Finally, the 3.8 factor is useful to remember when reading recipes
or the Zymurgy style guidelines. This is not a criticism of what
is in many ways a very fine book, but Papazian's suggested HBU
additions in one of TNCJOBH style tables in the middle of his book
strike me as somewhat high for some of the styles. Now, as our
"mileage may very," these may in fact work well for the homebrewer
getting a sort-of boil on the stove. But, if you use fresh hops
and get a good boil, then take that into account!
`

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