Use extra yeast (3gm per liter will ferment twice as fast as 1 gm per liter. With turbo yeast, you can ferment 18-20% in 3 days. Maintain the temperature between 20 to 25 degree Celsius Add a little quantity of sugar syrup daily rather than all at once. If your recipe calls for 210 gm of sugar per liter, add 70 gm daily for 3 days rather than 210 gm on the first day. This will prevent the dehydrating effect of sugar from slowing down the yeast metabolism. Always hydrate the yeast for 15 minutes at room temperature water (less than 30 degree Celsius temperature) so that it hits your wine running.