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.