ProcessDay 1: Peel the bananas if carbide or pesticides are used. If they are homegrown organic, then one can wash them and use the peel (Adds tannins and golden color). Try to cut them in small pieces without mashing them. The goal is to increase the surface area for the yeast to eat them.
If there is excessive mold damage, then we can boil the bananas for 30 minutes. Keeping them tied inside a cloth bag will prevent charring or off-flavors. Campden (1/2gm for 4 liters) is added commercially to kill wild microbes and to avoid the hassle of boiling fruit.
Add grape juice to add to the body and water to make the volume to about 1.5 liters (Banana has heavy sediments which leads to a lot of wine loss)
Add some enzymes (Pectinase & amylase). Pectinase helps to loosen the binding between the cells and amylase will remove the starch haze seen with a few tropical fruits.
Add sugar until the hydrometer reading is 1.100.
Regulate the pH to 4.0 using a pH meter, acid blend (decreases pH) and CaCO3. (increases pH)
Cover with a lid and wait overnight for Campden to dissipate away.
Day 2 onwards
Time to add yeast, yeast nutrients
Stir twice every day so that the top layer does not develop mold.
Refer to basic grape wine recipe for the rest of the steps. Move to secondary fermenter once the hydrometer reads ~1.040
Keep in the secondary for about 4 to 8 weeks to get a clear golden color beverage. (Follow the grape wine steps for the rest of the process)