Wash the rhubarb sticks and cut them into half-inch, or thinner slices. Place these pieces in a clean, sterilized tub and pour in the sugar. Stir it well, and then cover the bucket with a clean towel or plastic wrap and leave for at least 24 hours but up to three days.
After that time, the sugar will have pulled the moisture out of the rhubarb, creating a rich pink syrup.
Bring four quarts of water to a boil, hold it there for five minutes, and then allow it to cool to lukewarm. While it's cooling, make a large mug of strong black tea with some of the water and allow that to cool too.
Pour the lukewarm water over the rhubarb and sugar. Stir well to dissolve any of the sugar at the bottom of the tub. Pour the liquid through a strainer* into another clean tub. Discard the rhubarb pieces (or use them to make rhubarb pie).
Pour the tea into the rhubarb liquid.
If you want to know exactly what percentage of alcohol your wine is at the end, take a reading with a hydrometer. This is optional but will give you a better idea of what your wine is like in the end. You'll probably get a reading of about 1.1.
Initial fermentation
Next, add yeast and yeast nutrient to the rhubarb liquid. Stir well then cover the tub with a clean towel and allow it to sit undisturbed for five days. If you want to be more professional in this step, you can use a primary fermenting bucket with an airlock. Fermentation will be pretty violent in this stage though so it can get messy with one.
At the end of the five days, rack the liquid through a sterilized hose from the tub into your clean demi-john. The way I do it is to set the tub on a kitchen counter and the demi-john on the floor. If you don't have an auto-siphoning tube, place one end of the siphoning tube in the tub, then suck on the other end until the liquid begins coming through. Hold the end of the tube over the demi-johns' opening so that it flows inside. You could put it inside too, but be careful to not let the outer surface of the tube touch the inside of your demi. There will be germs from your mouth on the end.
As the liquid flows into the demi-john, make sure the tube doesn't suck up the mucky residue at the bottom of the tub. If a small amount gets in that's fine, but the less you get in the better. If the liquid doesn't come up to the bottom of the container's neck (and you're aiming for a dry wine) you can fill it up to this point with water that's been boiled and cooled.
Second Fermentation
Once the liquid is in, fit your drilled cork into the demi-john. Pour a little boiled but cooled water into the airlock's chamber before fitting it into the cork.
Leave the wine to ferment in a place that's at least room temperature, if not warmer. The temperature that the wine should be during its fermentation varies depending on the type of wine yeast you're using so look at the sachet for this information. You can purchase an LCD thermometer strip to put on your demi-john but I point the thermometer gun I use for soap making at it to take regular temperatures.
When your wine gets fermenting, you'll know it by the blip, blip, blip, of the water in the airlock. It can get annoying when you're sleeping, so keep it out of earshot while you get your zzz's. Fermentation can take a few days to start, so keep an eye on the temperature of the room/wine and be patient.
It will take about 4-8 weeks for fermentation to complete. By this time, the airlock may only be releasing a bubble of glass every minute or so or none at all.
Aging the wine
Rack the wine from the demi-john into a clean tub. Like before, avoid sucking up the sludge at the bottom. It's basically the remains of yeast and will make your wine look and taste horrible.
Add a crushed Campden tablet to it. Campden tablets contain sodium or potassium metabisulfite which stops mold and bacteria from growing in your wine and spoiling it during the aging process. Adding it is not optional.
Siphon the wine into another clean and sterilized demi-john. If the wine doesn't come up to the neck of the bottle, top it up with simple sugar syrup*. Too much oxygen touching the wine during aging can adversely affect the flavor of the wine. Make sure to add potassium sorbate too, so that any remaining yeast doesn't start fermenting the added sugar. If it does, you'll likely have a mess on your hands with the bung popping out during the aging process.
Fit a cork and then allow it to age for about six months. During this time it should be kept in a dark place at a constant cool temperature and the demi-john stored upright.
After six months, the wine will be pale golden in color, and probably quite dry (unless you added sugar syrup). If you use the hydrometer to measure the liquid's specific density again, you can now work out the alcohol content. It's likely that you'll get around 0.998 in this second reading, making the wine about 13.39% alcohol (if your initial reading was 1.1). If you want to leave it this way, you can skip the next section.
To sweeten the wine
Have a taste, and if the flavor of the wine is too dry for your liking, you can sweeten the wine with a rich simple sugar just before bottling it.
Dissolve 1 cup sugar in 1/2 cup of boiling water. Boil for a few minutes to evaporate a little of the water. Allow this strong simple sugar syrup to cool to room temperature.
Rack the wine into a clean tub then add the sugar syrup and the potassium sorbate* and stir well. The sugar will sweeten the wine, and the potassium sorbate will ensure that the yeast doesn't rise from the dead to devour the sugar. If you leave the potassium sorbate out, your bottles of wine could eventually explode. Take another hydrometer reading if you'd like to work out the alcohol content
Rack the wine into bottles
Siphon the wine into clean and sterilized wine bottles and cork. You could technically drink it immediately but it's better to let it age a month or longer.
Notes
*Any rhubarb pieces left in the wine after this point may mold so remove all that you can.* Make a simple sugar syrup by dissolving 6 oz (170 g) white sugar in a pint (454 g) of boiling water. Allow it to cool to room temperature before adding.* If you previously added potassium sorbate, you don't need to add it a second time.