Chop the rhubarb into 1/4 inch slices. Place the chopped rhubarb in a large bowl, glass jar or bucket.  

Cover with sugar and stir to coat. Allow the sugar to extract the rhubarb juice for 2-3 days.

After 2-3 days, there will be about 1/2 gallon of rhubarb juice or rhubarb syrup. Strain the juice/syrup through a fine mesh strainer and measure the juice.

Wash the remaining rhubarb chunks in enough water to make just under a full gallon of liquid. Strain again and add the rhubarb water to the fermentation vessel almost fill it up, leaving a bit of space for the remaining ingredients.

Add the winemaking tannin and yeast nutrient and stir to dissolve.

Dissolve the yeast packet in a small amount of lukewarm water and allow it to bloom for 5 minutes before adding it to the fermentation vessel.

Allow the rhubarb wine to ferment at room temperature for about 6 weeks. If you choose, rack the wine into another fermentation vessel after about 2 weeks, leaving the sediment behind. This will result in a less cloudy finished wine.  

Once fermentation is complete, use a siphon to bottle the wine leaving behind any sediment. While you can drink it immediately, it's better if you can bring yourself to wait at least a month.