In article >,
"Paul E. Lehmann" > wrote:
> Wildbilly wrote:
>
> > In article >,
> > "Paul E. Lehmann" > wrote:
> >
> >> fishziblu wrote:
> >>
> >> > it is my second go at making wine,and i've noticed that after the
> >> > first fermentation,the ph increases. When i crushed the grapes my
> >> > reading was 3.4, however on my first racking the ph has gone up to
> >> > 3.9. Is there a reason for this? Should i check the wine more often? i
> >> > have added some tartaric now. During the time it spent with a high ph
> >> > could it spoil itself?
> >> It is common for the pH to rise during or after fermentation. If you did
> >> not add any Malo Lactic culture, your grapes probably underwent a ML
> >> fermention from the natural culture on the grapes. You did the right
> >> thing by adding
> >> tartaric. You also need to protect your wine with SO2 and the amount you
> >> use depends on the new pH of your wine after you added the tartaric.
> >
> > Good news is that the pH is just about right for Robert Parker;O)
> >
> > You need some way of measuring the "free" SO2. The Ripper method calls
> > for a starch indicator, sulfuric acid, an Erlenmeyer flask, and a
> > burette. Otherwise you risk O.D.ing your wine on SO2. Nothing like 100
> > parts per million (ppm) of SO2 in your wine to give you a blinding
> > headache.
> >
> > For the addition, I use 1 lb potassium metabisulfite per 1 gallon of
> > water to make a 5% solution.
>
> WHOA, Wildbilly. Are you sure of your units? I believe that one POUND of
> Potassium metabisufite would give you a LOT more that a 5% solution. Try
> 100 GRAMS in one LITER for a standardized solution. This is a 10%
> solution. See
>
> http://www.brsquared.org/wine/Articles/SO2/SO2.htm
>
> section 19 on the details.
>
> Paul
>
>
> > Then the formula is ppm of SO2 that you
> > want to add, times the gallons added to, times the fudge factor of .063
> > equals the number of milliliters of 5% SO2 solution to add (#ppm X
> > gallons X .063 = # mls). Initially the SO2 will bind to aldehydes,
> > sugars, proteins, etc. and you won't see the number of ppm of SO2
> > expressed, but once these compounds become saturated with SO2, you'll
> > get more of a linear response. The bound SO2 has little effect on
> > micro-organisms, which is the job of the "free" SO2. The effectiveness
> > of the SO2 is dependent on the pH of the wine. For a pH of 3 to 4, use
> > 30 to 40 ppm SO2. This is a rough rule of thumb but should serve you
> > well.
19. Stock Solutions, third paragraph, fifth line, "Since potassium
metabisulphite is only 57.6% SO2," your 100 grams per liter is a 5.76%
solution. My suggestion was 1 pound of metabisulfite/gallon H2O. A
gallon is eight pounds plus the pound of metabi = 9 lbs. 1/9 =
0.11111111. Mutiply this by the efficency of 57.6%, (1/9) X .576 = 6.4%
SO2. This is wine making, not rocket science. If you are trying for 32
ppm and get 30ppm or 34ppm, it's no big deal.
You'll also notice I was much more bref than
http://www.brsquared.org/wine/Articles/SO2/SO2.htm ;O)
--
"When you give food to the poor, they call you a saint. When you ask why the poor have no food, they call you a communist."
-Archbishop Helder Camara
http://www.jpost.com/servlet/Satelli...cle%2FShowFull
http://countercurrents.org/roberts020709.htm