Try this strain out:-
Gervin GV4 High Alcohol White/purple label£1.05 (S. Cerevisiae French strain)
Experiment have shown that with suitable additions of an appropriate nutrient to the must levels of alcohol in excess of 21% can be achieved using this yeast. It ferments fast, produces little foam and settles firmly and quickly. It also produces excellent full bodied fruit based wines and desert wines. This is a new yeast with a great potential for the amateur winemaker. It has a killer factor which may inhibit unwanted wild yeasts.
To use add the contents of the sachet to about 50ml of warm water (approx 35°C) containing 1/2 teaspoon of sugar. Simply leave for 15-20 minutes, stir vigourously and add to the must. Stir the must well to distribute the yeast.
Each sachet contains 5 grams of yeast which is sufficient for a single fermentation of up to 5 gallons
Sorry, forgot to ask ; do you get the Gervin yeast range that side of the pond or are you guys using other strains as standard?
With thanks
Lee