How to select for best flavor:
Choose firm, crisp, straight and fairly thick stalks. Color will not help in determining ripeness, but it can let you know if you are getting a field variety or a greenhouse variety. Field rhubarb has deep, red stalks and bright-green leaves. It has a very distinctive, tart flavor. The color of greenhouse rhubarb ranges from light pink to light red, with yellowish-green leaves. Greenhouse rhubarb has a milder flavor and less strings than field rhubarb. Rhubarb is very perishable and needs to be refrigerated.
Peak of the season:
Thanks to greenhouses, rhubarb is available all year round. The State of Washington supplies most West Coast rhubarb. Michigan supplies the east. Rhubarb is most plentiful in April and May.
Rhubarb is an excellent source of calcium. It also contains small amounts of other vitamins and minerals. Because sugar must be added to rhubarb, it is fairly high in calories. One cup cooked with sugar contains about 280 calories, with almost no fat and only 2 mgs. of sodium. To cut down on the calories, cook rhubarb with sweeter fruit, like strawberries, and add less sugar or sweeten with honey. The leaves should not be eaten, but they are good for boiling out discolored pots.
Rhubarb comes originally from Russia, along the Volga river. When raw, it has a high content of oxacilic acid, which can be fatal if eaten in quantity. It would be interesting to know how many people died experimenting with rhubarb in its early days. In Western Europe, rhubarb was not recognized as a food until the 1770s. In the early 1800s, rhubarb pie became very popular in New England. In 1947, rhubarb was legally ruled to be fruit by the U.S. Customs Court in Buffalo, NY. Judge Genevieve Cline ruled that since rhubarb is principally used as a fruit, it should be legally considered one as well.