Dessert wine help

JoAnn wrote "I am making a dessert wine from Vidal Blanc grapes. I need a little

Hi JoAnn - I'm about ready to do the same thing. I still have about 100 pounds of Vidal hanging in the vineyard and I'll pick the night before a hard freeze is expected. I think my Vidal are at about the same brix as the ones you have. Some of my comments below are based on a recent attempt to stop fermentation of Baco Noir at 10 brix with addition of Everclear and freezing temperatures. It's hard to stop yeast once they get going. My comments are a little long but this is an interesting topic.

Bill Frazier Olathe, Kansas USA

1. Stop fermentation at 1.020 with sulfite JoAnn - Yeast 1118 will tolerate alcohol up to 18% alcohol according to the Lallemand charts. Your 8.5 gallons, starting at 1.102, will result in about

13% alcohol if fermented to dryness. I think you will have a hard time stopping fermention period. I don't believe sulfite alone will do it. You probably will have to shock the yeast with near freezing temperatures, rack of the settled yeast, and repeat this step until there is very little yeast left in the wine.

1. Add sorbate If you are able to stop fermentation as described above then you will have a very low population of yeast to deal with. Sulfite plus sorbate may then be effective to stop and prevent any renewed fermentation of the remaining sugar.
2. after about 2 weeks rack into a primary, add juice, check sulfite and rack into clean carboys. If you are able to stop fermentation at 1.020 there will be about 5% sugar left in the wine. That may be sweet enough, perhaps not. If you add the

0.6 gallon of juice that will bring the sugar up to about 6.5%.

Questions; What level should the sulfites be?

-I believe the sulfite level should be what you normally would add to protect the wine. In other words don't depend on sulfite to stop fermentation.

Should I use sorbate?

-Unless you can sterile filter, and keep the wine sterile through the bottling step you will have to use sorbate or it will ferment again.

Should I add the juice at a different time?

-I would let the main wine ferment to dryness. Age normally to let the wine become very clear. Then add the reserve juice plus sorbate.

At what point should I add sugar, if necessary?

-If addition of the reserve juice doesn't make the wine sweet enough then you can add sugar.

JoAnn,

You would have to add a HUGE amount of sulphite to stop a fermenting wine, especially using a vigorous strain like EC1118. Besides, most of that sulphite will just become bound to acetaldehyde rendering it useless. I suggest to chill to wine to a very low temperature, and rack of the sediment. Aim is to reduce the yeast population substantially. Then add some sulphite and sorbate (sorbate will only prevent reproduction of the yeast).

At least 0.6 mg/l *molecular*. This depends on pH, and bear in mind SO2 binding. See

for more.

Yes. I'd use about 220 mg/l (29 oz/1000 US Gal). Make sure your SO2 levels are satisfactory though!

Timing should be OK, just ensure fermentation has stopped first.

HTH, Ben

Improved Winemaking

Bill:

I've done it this way before, but I've head of people adding the reserve juice in ASAP. The idea being that it's not clarified, so adding it later to clear wine would mean the wine has to be fined again. Do you find you need to fine again?

JoAnn:

One point that Bill did not make - for the sugar you're planning to have, your TA is too low. You'll need to ad some acid before fermentation to get a balanced result. I'd shoot for at least 7.5 g/L.

Pp

JoAnn/Pp - I didn't see JoAnn's response to my comments about the Vidal dessert wine. I just now saw them as part of Pp's post. I must not receive all posts to r.c.w.

With regard to when to add the reserve juice. If you add the juice early, before any remaining yeast has been put to sleep, it will just ferment out and any sweetness from the reserve will be lost. Why not let the reserve juice clear on it's own at near freezing temperatures. Then add before filtering or bottling. I have been letting all of my juice for white wine sit at 40F for two days (it's sulfited) before starting fermentation. The juice I rack away from the sediment it very clear.

Pp is right that the acid is low. His target of 7.5 g/L is good. And everyone that posts here says to add acid before fermentation. I make good tasting Vidal with 5.0 g/L acid but it's finished dry. Probably would taste even better with more acid.

I have an empty bottle of Niagra area Vidal ice wine. The label says it started at 41 brix and finished 251 g/L residual sugar (25brix? ) and 12% alcohol. I calculate 10.6% alcohol assuming the wine fermented from 41 to

25 brix so I'm off somewhere. How sweet do you plan on making your wine JoAnn?

Bill Frazier Olathe, Kansas USA

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Hi All, Thanks for the advice. On the Ta, the vineyard owner came up with

7.0TA with his testing equipment and I suspect my testing stuff might be a bit old. So I do think the ta is higher than I stated in the origonal message. I will let it ferment to dryness or near dryness. I do not have the ability to chill the wine easily. House temp is 70 +- 5. All of my wines ferment in the utility room, dining room or living room. We do plan to turn our back portico into a winery but that won't be for a while. I will settle out the juice I have in the freezer before I add it to the wine. (I use my washing machine spin cycle to do that). The juice is sulfited. Will print out all of your comments to make my final decision on proceedure from this point. Meanwhile, the wine can sit and ferment. Thanks to all JAM