Can't get the fermentation started

[choosybeggar]

I've made lots of AG beer, this is my first wine.

I purchased and crushed 100 lb Riesling grapes with a yield of approx 6 gallons of juice. My plan (from "The Way To Make Wine-kind of a crappy book but what I have) was to add 4 g of potassium metabisulfite to the grapes as they entered the crusher but the brew shop didn't want sulfites in the crusher. Therefore, I added to entire 4 g (8 tsp of a 10% solution-about 40cc) to the juice. I realize now, had I added it before the crush and squeeze, as directed by the book, the final amount in my juice would be lower than by adding directly to the juice, so I began to worry about too much sulfite.

pH was 3.1 and sugar was 20 degrees brix by refractometer. I added .75 lb sucrose in boiled water to achieve a final brix of 21. Must temp was about 59F. I rehydrated my Cote de Blanc yeast according to manufacturers directions, inoculated, added 6 g yeast food, and 24 hours later, nothing. I warmed the must to about 68 degrees, this time made a mini yeast starter (rehydrated with 1/3 must and 2/3 water, waited until CO2 evolution was evident and pitched). Still nothing after 24 hours. Then I checked sulfite concentration with titrets and saw a value of 40 ppm, I splashed the must back and forth to aerate/liberate SO2, made a real starter (1 qt consisting of 1/3 juice, 2/3 water and a pinch of yeast food), pitched after 6 hours of active starter fermentation, and 8 hours later, still no signs of fermentation.

Help! What the hell is wrong?

 

[Yooper]

I've made lots of AG beer, this is my first wine.

I purchased and crushed 100 lb Riesling grapes with a yield of approx 6 gallons of juice. My plan (from "The Way To Make Wine-kind of a crappy book but what I have) was to add 4 g of potassium metabisulfite to the grapes as they entered the crusher but the brew shop didn't want sulfites in the crusher. Therefore, I added to entire 4 g (8 tsp of a 10% solution-about 40cc) to the juice. I realize now, had I added it before the crush and squeeze, as directed by the book, the final amount in my juice would be lower than by adding directly to the juice, so I began to worry about too much sulfite.

pH was 3.1 and sugar was 20 degrees brix by refractometer. I added .75 lb sucrose in boiled water to achieve a final brix of 21. Must temp was about 59F. I rehydrated my Cote de Blanc yeast according to manufacturers directions, inoculated, added 6 g yeast food, and 24 hours later, nothing. I warmed the must to about 68 degrees, this time made a mini yeast starter (rehydrated with 1/3 must and 2/3 water, waited until CO2 evolution was evident and pitched). Still nothing after 24 hours. Then I checked sulfite concentration with titrets and saw a value of 40 ppm, I splashed the must back and forth to aerate/liberate SO2, made a real starter (1 qt consisting of 1/3 juice, 2/3 water and a pinch of yeast food), pitched after 6 hours of active starter fermentation, and 8 hours later, still no signs of fermentation.

Help! What the hell is wrong?

Go stir the must like crazy, to see if you can get some of the s02 to dissipate. I don't know how much 4 g of K-meta is, but it sure seems like a lot for 6 gallons. I'd just stir, stir, stir, stir, stir, uncovered, then cover it with a clean towel and do it again in an hour. Do that several times over 24 hours, and that should get some of the excess s02 out of there. 40 ppm is fine, but I wonder if it's higher than that and your titration isn't accurate.

You could start another starter, too, without any of the must at first, of just some sugar and water, and then add diluted juice (mostly water) until the yeast gets going well and acclimated and then add more diluted juice. Keep doing that, and add more juice and less water, as long as fermentation keeps going. When you're adding 100% juice, and fermentation is still going, then add it all to your must. This might take 24 hours for the process.

That should fix you up.

 

[WilliamSlayer]

Yoopers right. The sulfite is the problem. Gass ing it off is really the way to get back on track.

 

[choosybeggar]

Thanks for the suggestions. The airlock is finally bubbling after adding a starter that was ramped up to full strength wort. Now I have an unrelated question regarding Cote de Blanc yeast that I will post in a new thread.