Study: RHUBARB. 2.4 Rhubarb becomes liquid.
Rhubarb is not unjuiceable. Rhubarb juice is delicious. And Grant Achatz’ juicer foreshadows the Machine takeover to come
Foams, jellies, sorbets, soups — yes, rhubarb soup is a thing — all require getting the flavor of rhubarb into a liquid
Some recipes call for poaching rhubarb in liquid, sometimes with a small amount of sugar added to the liquid, then sieving, using the cooking liquid as the juice.
This method might make sense if you want to get flavor into a liquid like alcohol without diluting it. It does not make sense to get flavor out of something that is already more than ninety percent water. It gives great color, though.
Process: Trim rhubarb. Slice into 2 – 4 inch segments. Make a weak syrup of 1 part sugar to 2 part water. Simmer rhubarb in syrup without boiling or caramleizing liquid.
Result: Slightly-acidic, though very pink, weak sugar syrup, with little rhubarb flavor. Adding pureed poached rhubarb into mixture would probably help.
2. Stick it in a juicer raw, then filter.
Grant Achatz, of Alinea and Next, uses rhubarb juice as a base for, umm, various amazing things that might be described by various nouns.
Achatz’recipe calls for processing the rhubarb through a juicer, then running the juice through a coffee filter.
Achatz’ juicer must be a truly terrifying machine. Rhubarb stalks, where not water, are mostly cellulose fibers. Trying to juice raw rhubarb is like trying to puree a bundle of fishing line.
Even if the juicer is not defeated by the rhubarb, rhubarb’s filaments will break the next step. Because of the fibrous quality of the puree, it will not easily flow through filter paper. To extract the juice, it was necessary to place the puree inside filter paper or fine-grained cheese cloth and manually wring the liquid from the puree.
Process: Trim rhubarb. Place in blender. Attempt to puree. Repair blender. Decide to dice rhubarb first. Place in blender with small amount of water as starter liquid. Puree.
Squeeze like hell.
Result: A purple-grey color never seen by any human before. After an hour, the juice turned pink and its cloudiness dissipated as a mysterious black residue precipitated out of the solution. This may be natural. Or it may be the pulverized remnants of the blender’s blades. A bracing taste akin to dental etching acid, but somewhat more drinkable. A bit of tannic astringency. Very ripe rhubarb might make this palatable.
There are less annoying methods out there, but this may be the best way to get to rhubarb’s acidity for uses like vinaigrettes without adding sugar.
(And do not juice the leaves, they will kidney you.)
3. Macerate in sugar until just tender enough to puree, then filter.
This blog does not have Alinea’s juicer. It has a forty dollar blender.
This method worked well in a forty dollar blender.
Process: Trim rhubarb. Pack rhubarb in sugar for 20-30 min. Remove excess sugar. Slice into 2 in. segments. Puree. Press puree through coffee filter or fine-grained cheesecloth.
Result: An orangish pink liquid, with some cloudiness. A crisp sour taste, with sweetness at about the level of a grapefruit juice cocktail. Flavor reminiscent of strawberry-banana smoothie.