Ive been to this site a dozen times, and "happened" on this today. Mods, this is from Kellers site, please delete if this is not allowed.
There are basically four approaches to making wine from rhubarb, but all require cutting it into pieces first. (1) The pieces are then crushed and pressed to extract the juice, which is fermented; (2) the pieces are covered with sugar to draw out most of the juice as liquor, which is then separated from the pieces and fermented alone or fermented pieces and liquor together and pressed before transfer to secondary; (3) the pieces are frozen, thawed and then processed as (1); (4) the pieces are frozen, thawed and then processed as (2).
Here are four recipes using the four approaches. Two use precipitated chalk to buffer oxalic acid because the rhubarb used seem to require it, while two do not because the rhubarb used tasted fine. You have to use your own judgement regarding your own rhubarb.
Rhubarb Wine (1)
6 lbs rhubarb
2 lbs sugar
2 tsp citric acid
1 tsp yeast nutrient
6-1/2 pts water
1/2 oz precipitated chalk
1 finely crushed and dissolved Campden tablet
Wine yeast (Montrachet or Champagne) in starter solution
Trim, wash and cut the rhubarb. Add 5 pints of the water into which is dissolved 1 finely crushed Campden tablet and the sugar. Cover and set aside for 3 days, stirring twice a day. Strain the rhubarb (save the water) and press it dry, then discard the pulp. Combine the sugared water and juice and add the chalk; when the fizzing subsides, add the remaining ingredients (except the reserved 1-1/2 pints water) and ferment in gallon jug covered with clean cloth until vigorous fermentation subsides. Add reserved water and attach airlock. Ferment to dryness, racking every 3-4 weeks until clear. Stabilize, sweeten to taste and age about 3 months. Rack if needed and bottle. Allow 8-12 months before tasting. [Author's own recipe]
Rhubarb Wine (2)
4 lbs rhubarb
1 cup white grape concentrate
1 lb 13 ozs granulated sugar
1-1/2 qts boiling water
1 tsp citric acid
1 tsp yeast nutrient
1/4 tsp grape tannin
2/3 tsp pectic enzyme
1 finely crushed and dissolved Campden tablet
2 qts cold water
1 pkt Champagne wine yeast
Place cut rhubarb and sugar in primary and mix well. Cover primary for 24 hrs. Crush rhubarb with a piece of hardwood or the bottom of a non-punted wine bottle. Pour boiling water over the crushed rhubarb, stir vigorously and recover primary. When water cools, ladle or scoop rhubarb into a straining bag and squeeze as much of the juice out as possible. Discard pulp. Add the grape juice, citric acid, yeast nutrient, tannin, crushed Campden tablet, and cold water. Cover and wait 12 hours. Add pectic enzyme, recover and wait another 12 hours. Add activated yeast starter and ferment until vigor subsides. Transfer to secondary, ferment to dryness, rack every 3-4 weeks until clear. Bottle dry or stabilize and sweeten, age 3 more months, rack if needed, and bottle. Age 6-9 months before tasting. [Author's own recipe]
Rhubarb Wine (3)
4 lbs rhubarb
2 lbs sugar
juice of 2 large oranges
2/3 tsp pectic enzyme
1 tsp yeast nutrient
6-1/2 pts lukewarm water
Red Star wine yeast
Wash and cut the rhubarb, then place in ZipLoc freezer bags and freeze at least a week. Dump in colander to thaw over primary. When thawed, squeeze out as much of the juice as you can. Stir in remaining ingredients except yeast. Cover and set aside 12 hours, then add activated yeast in starter solution and recover. Recover and ferment 3 days. Stir, pour through funnel into secondary and attach airlock. Ferment to dryness. Rack monthly until clear. Bottle dry or stabilize and sweeten, age 3 more months, rack if needed, and bottle. Age 6-9 months before tasting. [Author's own recipe]
Rhubarb Wine (4)
4 lbs rhubarb
2 lbs sugar
350 mL pineapple juice or 450 mL orange juice
2/3 tsp pectic enzyme
1 finely crushed Campden tablet
1/2 oz precipitated chalk
1 tsp yeast nutrient
Water to 1 gal (about 6-1/2 pts)
Campagne wine yeast activated in starter solution 12-14 hours prior to use
Wash and cut the rhubarb, then place in ZipLoc freezer bags and freeze at least a week. Remove and place in primary to thaw. Sprinkle very finely crushed Campden tablet and then the sugar over rhubarb in even layer. Cover primary with lid or plastic sheet for 36 hours. Sprinkle pectic enzyme and precipitated chalk over mixture, stir well and recover the primary. Wait additional 36 hours and add all remaining ingredients. Ferment about 5 days, then strain out the rhubarb and press it. Combine pressed juice with fermenting liquor, transfer to secondary and affix airlock. Ferment to dryness. Rack monthly until clear. Bottle dry or stabilize and sweeten, age 3 more months, rack if needed, and bottle. Age 6-9 months before tasting. [Author's own recipe)