Problem with preservatives?

[Shanghai Wine Maker]

I am trying to make wine using what was advertised as frozen blueberry puree with no preservatives and 10% added sugar.

I pitched the yeast two days ago, but I am not seeing any significant bubbling.

The blueberries do not seem to be a puree - more frozen juice, no solids. I am wondering if they were also preservative free. They are supposed to be an imported product, so should be able to trust the label, but in China these things always have some risk. It could be a fake import and there could be preservatives.

Any suggestions on next steps?

Just wait? Pitch yeast again? Something else?

I know the yeast is good - I used it a month ago to do an orange wine and a banana wine, both with fresh fruit, and both fermented happily.

 

[wood1954]

Blueberries can be hard to start try making up a good ferment then add it to the must.

 

[Shanghai Wine Maker]

OK. So just a ferment in sugar water?

 

[ibglowin]

Maybe warm up the must if its cool.

 

[winemaker81]

Make an overnight starter -- in a wine bottle put 1 cup warm water (90-95 F), yeast, 1 tsp sugar, and 1/2 tsp yeast nutrient. Swirl to stir, cover lightly (a paper towel is fine), and let rest on the counter overnight. The initial temperature is good for yeast, bad for wine, but it will cool down before pitching.

I ferment in my cellar, which tends to be cooler, so I leave the bottle on my kitchen counter for at least a few hours, then move it to the cellar to acclimate.

The next day, swirl to blend, and gently pour down the side of the fermenter so the starter doesn't spread much. Do not stir for at least 24 hours.

I got this method from Finer Wine Kits, and every batch since then has started quickly.

 

[ChuckD]

I thought I read here that after about 8 hours you increase the starter volume about 25% with the must and repeat this one more time 4-6 hours later. It’s supposed to acclimate your yeast to the must. Either way you are giving the little yeasties a head start.

 

[winemaker81]

I thought I read here that after about 8 hours you increase the starter volume about 25% with the must and repeat this one more time 4-6 hours later. It’s supposed to acclimate your yeast to the must. Either way you are giving the little yeasties a head start.

Some folks do that and it make sense. I like the overnight starter as it's less effort and has proven success. YMMV

 

[heatherd]

Bubbling isn't a good indication of fermentation. Were you able to get a hydrometer?

 

[Raptor99]

I thought I read here that after about 8 hours you increase the starter volume about 25% with the must and repeat this one more time 4-6 hours later. It’s supposed to acclimate your yeast to the must. Either way you are giving the little yeasties a head start.

Adding some of the must in stages to the starter is helpful if the pH is low. It helps the yeast acclimate to the harsh environment. I do this with my cranberry wine, which is even more acidic than blueberry.

Waiting X number of hours is only an approximation. Yeast don't look at the clock. When they have reproduced and are happily consuming the sugar, evidenced by the bubbles and smell, it is time to move on to the next step. @heatherd I agree with your comment about the OP. But when making a starter, the bubbles + yeasty smell is a pretty good indication that it is working.

 

[Jusatele]

there are a few times I can revert back to the beer makers process of making a yeast starter. I have a flask and stir plate left from then and I can make up a nice size starter for hard to start wines. Skeeter Pee and wines made from canned fruits seem to do best if making a starter and then pouring it in.
a beer starter is usually done in a liter flask, fill half way up with wort (must to winemakers) add yeast and magnet, set on stir plate for 24 hours. then pitch.
As a beer brewer you can study yeast and for best fermentation you are trying to pitch when the yeast are populating. OK beer ferments way faster than wine because of the lower ABV and techniques used. Controlled temperatures, pitching amounts, introducing oxygen before pitching, balancing PH, doing a mash to optimize enzyme reaction, etc.
Most home wine makers are not trying to keep the must at a 2 to 3 degree variable, make starters, do more than swirl the wine. Add to that using fruit that can have preservatives in it and some wines and a slow fermentation can be possible. Using a hydrometer is about the only way to tell how a fermentation is going.