hist-brewing: phenolic compounds / water chemistry

George de Piro gdepiro at mindspring.com
Thu Jan 13 06:23:14 PST 2000


Hi all,

> Eylat Poliner <allotta at earthlink.net> wrote:
>
> >Pheonolics are normally caused by bacterial contamination. The
> wild yeasts
> >on the
> >skins will not do that.

I will second Jeff's comments:  phenolics are the hallmark of wild yeast
activity.  Other signs of wild yeast are over-attenuation of your wort, thin
body, and astringency in the finish.  The astringency is caused (in large
part) by the same phenolic compounds that give the beer a medicinal
character.

There are different kinds of phenols, each with distinct flavor
characteristics.  On top of that, everybody is different and some people
will perceive certain chemicals differently from others.  Phenolic compounds
are most frequently described as band-aid, plastic, burnt plastic,
electrical fire, smoke, spice, clove.  If any of these flavors occur in your
beer wild yeast is the most likely culprit (unless you used cloves in the
brew, or molten plastic; that would definitely be out of period, though).
--------------------------------------
Ox writes in asking for comments about how to adjust his tap water to more
closely match London's.  He provides a handy chart (below):

> City            Ca++    CO3--   Cl- Mg++    Na+ SO4-    HardnessTDS
> London          90      125     20  5       15      40      235     300
> Stillwater, OK  75      40      296 64      279     116     140     456
>
> pH of the city supply is also quite high - 8.25.
>

I am not trying to be insulting, but the water of Stillwater, OK is some of
the worst I have seen an analysis for!  Where is all that sodium chloride
(NaCl) coming from?  Do they salt the roads around your reservoir
excessively?

The only option you have is to dilute your tap water in distilled (or
otherwise deionized) water to get the NaCl down to reasonable levels.  If
you are trying to mimic London water, that would mean a 14 times dilution.
This would bring your sulfate down too low, though, as well as your calcium.
You could then add back some Calcium and Sulfate in the form of gypsum, but
this will bring your sulfate levels way too high:

mole weight of CaSO4 = 136; Ca++ = 40, SO4-- = 96

so adding 5.8g of CaSO4 to 19 L (5 gal) of purified water would put it at 90
ppm Ca but would also add 215 ppm SO4.  This will have an "unLondon" effect
on the beer's flavor.

You could add the calcium back as CaCO3 (chalk); this does not dissolve
readily in water without acidification, and it will also raise your
carbonate levels (to hopefully appropriate levels):

mole weight CaCO3 = 100, Ca++ = 40, CO3-- = 60

so adding 4.25g of CaCO3 to 19 L of purified water will yield 90 ppm Ca++,
and will also add 134 ppm CO3, which is pretty close to your target, so
there you go!

Hopefully all my math and stuff are correct; where's AJ deLange when you
need him?

Have fun!

George de Piro

C.H. Evans Brewing Company
at the Albany Pump Station
(518)447-9000
http://evansale.com (under construction)

Malted Barley Appreciation Society
Homebrew Club
http://hbd.org/mbas


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