In article >,
"Paul E. Lehmann" > wrote:
> Wildbilly wrote:
>
> > 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)
>
> The above link takes the 57.6%, you correctly reference, into consideration
> when he gives the formulae for additions using the "Stock Solution" he
> makes.
Uh, Paul, YOU said above, that 100 grams of metabi per 1 litre would
give a 5% solution of SO2.
My point is that 1 lb/1 gallon is easier to remember than 86.8
grams/100ml (which you didn't). There is rarely a direct correspondence
between SO2 added and SO2 measured. If you add 15ppm SO2 to a new wine,
you may get a 5ppm or 10ppm of SO2 rise in the wine. If you want to
remember 86.8g/100ml, go for it.
I think everyone gets it.
--
"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
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