Here we go. You will need:
- One 5-litre plastic drinking water container (not five separate bottles)
- One 2-litre plastic coke bottle, empty
- One plastic pouring funnel
- Four 1-litre cartons of red or white grape juice with no preservatives
- 500 grams granulated white sugar
- One sachet of general-purpose wine yeast
Your grape juice should be kept at room temperature, not in the fridge. If you have placed your grape juice in the fridge, take it out and let it warm to room temperature before proceeding.
Drink the 5 litres of water (!) Most people prefer to do this over a few days. When the bottle is empty, there is no reason to rinse it out. It was full of drinking water, remember?
- Pour about half of your first carton of grape juice into the empty 5-litre bottle.
- Add half a teaspoonful of wine yeast, put the screw-cap on the bottle and shake it to mix in the yeast and aerate the juice.
- Leave the 5-litre bottle in a warmish place, but not in direct sunlight.
- The 5-litre bottle will have started bubbling. Add the rest of the first carton of juice and one more full carton. The 5-litre bottle is still under half full. Tighten the bottle cap then back it off half a turn. This is very important. Fermentation produces a lot of carbon dioxide gas which must be allowed to escape.
- Pour 500 grams granulated sugar into the empty 2-litre coke bottle. A plastic funnel makes this a lot easier. Pour cool boiled tap water or drinking water onto the sugar until the bottle is about half full (1 litre). Shake it until all the sugar is dissolved. Don't add it to the wine yet.
- Add one more carton of grape juice and all of the sugar syrup to the 5-litre bottle. The level should still be below the shoulder of the bottle. Swirl the bottle to mix in the sugar syrup.
- Tighten the bottle cap then back it off half a turn, as before.
- The liveliest fermentation should have eased off, so it's safe to add the last carton of juice, filling the 5-litre bottle to the bottom of the neck.
- Tighten the bottle cap then back it off half a turn.
When the bubbling has stopped (or at least slowed to the occasional bubble), place the bottle in the fridge (not the freezer!) and leave it for about three days. The cold will halt the fermentation and help the yeast settle to the bottom of the bottle.
After three days refrigeration, line up enough empty bottles to hold the wine. I use 1-litre plastic lemonade bottles. Very, very carefully, so as not to disturb the sediment, pour the wine into the empty bottles using the funnel. It helps to have someone else hold the bottles and move the funnel from bottle to bottle. Fill all the bottles in a single pass, without untipping the fermenting bottle. This way, you won't disturb the sediment. Cap the bottles and store in a cool dark place.
The wine can be drunk straight away, but it will improve in the bottle for several months. It's best not to consider 'laying it down' or any such nonsense. It's not that sort of wine.