John,
I don't know what the film is, but just skim it off if you don't smell
vinegar and splash the must, that may get it going. I normally don't
add water to Niagara but if the sugar was high too you should be OK.
It's not unusual for a wine yeast do do whatever it feels like, i have
seen them go immediately and seen them take a day and a half. No
experience with making Vidal, sorry.

Joe


John Fouts wrote:
> Hey newsgroup! It has been a long time since I have been on here. I have a
> couple of questions... - please keep in mind that I am still a new
> winemaker.
>
> 1.) I am driving up to Indy to buy some Vidal Blanc juice on Saturday
> that was pressed today. If I want to make a 6 gallon batch of wine from
> this, how much juice do I need? Previous recipes for other wines that I
> have made always called for adding a significant amount of water. A good
> recipe for Vidal Blanc would be nice as well if anyone has any suggestions.
>
> 2.) This one may be a bit more difficult to answer. My previous
> winemaking experience has come from 2 wine kits, and making several fruit
> wines. I have made Peach, Blueberry, and Strawberry for 2 years in a row.
> I recently went to pick some Niagara grapes from a relatives property. I am
> not sure how to grade quality of grape. All I know about these grapes are
> that the vines have been producing since pre-1940.
>
> I picked about 15-20 lbs. of grapes. This gave me enough juice to make one
> gallon of wine according to the Jack Keller website recipe for Niagara.
> Here is what I did. My wife and I, upon getting home the same evening after
> picking the grapes, de-stemmed the grapes. We then put them into a primary
> fermenter and added some tannin (1/4 tsp.) because we wanted this wine to
> last slightly longer than one year. Additionally, we added yeast nutrient.
> The following night, we strained the juice away from the grapes. We added a
> campden tablet as well. We did a basic titration and discovered that our
> tartaric acid content was too high, so we adjusted by adding water (did not
> have any potassium carbonate). The next morning, we looked at the mixture,
> and it appeared as if some natural fermentation was occurring. We pitched
> the yeast that morning. Now, 2 days later, it appears as if no fermentation
> is occurring, and there is a white film on top of the mixture. Can anyone
> advise me as to what is happening with this juice? I imagine that there is
> probably no way at this point to salvage the mixture, but I am curious to
> know what happened.