Harvest and use

Harvesting rhubarb |

When can I harvest? : Before harvesting your first harvest, you will have to wait. The year after planting, you will be able to harvest only a few stems. Usually, in the third year, the harvests will be more abundant. When the leaves are at their full length, you can take the stems. Harvest about 2/3 of the stems to allow the plant to regenerate. So you could even have a second harvest in the fall. On the other hand, the taste will possibly be more bitter.

Should we cut or pull out the stems? :
Rhubarb should be pulled out and not cut as this does not encourage the regrowth of new stems.

Here are two techniques that make it easier to remove the stems:

Either by gripping the base of the stem and pulling sharply sideways on the stem.
Always grip the base of the rod but this time we turn 1/4 turn while pulling on the rod.

Rhubarb harvest by Hélène Laurendeau

Harvesting rhubarb by Marthe Laverdière

Storing rhubarb |

Preservation in water: Once cut the stems can be preserved by filling a glass jar halfway with water and placing the rhubarb stems, base down, in the water . Cover with a plastic bag and refrigerate until ready to use. Rhubarb preserved in this way is intended to be used within a few days. If you don't have room to store the stalks upright, you can also keep the rhubarb stalks wrapped loosely in a plastic bag.

Preserving in aluminum foil: Arrange the rhubarb stalks on a large piece of aluminum foil. Wrap the foil around the rhubarb stalks loosely but snugly, gently squeezing the ends (you don't want it to be airtight) and place in the refrigerator until needed. Rhubarb should be kept like this for at least a month, sometimes more.

Store in the freezer: Rinse the rhubarb stalks with water and dry. Cut the washed rhubarb into 2cm pieces and arrange in a single layer on a baking sheet; freeze until solid, about 3 to 4 hours. Transfer the frozen rhubarb pieces to resealable plastic freezer bags and store in the freezer for up to a year, or up to three years if vacuum-packed.

Use of rhubarb in savory dishes around the world |

While rhubarb is most commonly used in sweet dishes, several countries incorporate it into savory cuisine:

United Kingdom: Rhubarb is traditionally served as a tart sauce with pork, similar to applesauce. It is also used in various savory dishes like rhubarb and lentil curry, pickled rhubarb with oysters, and rhubarb with roasted meats.
Scandinavia: Similar to the UK, a tart rhubarb sauce is a common accompaniment to pork dishes.
Afghanistan: Rhubarb is used in a traditional stew called "Qorma-e-rawash" with lamb and spices. It's considered a "cold" food with medicinal properties.
Iran: Rhubarb is used in stews and sometimes added to spinach dishes.
Poland: Rhubarb is cooked with potatoes and aromatics.
Morocco: Rhubarb can be found in tagines, such as lamb tagine with rhubarb and raisin couscous.
Canada: Rhubarb has a strong historical connection with the Métis people, who use it in traditional foods.
United States: While less traditional, savory rhubarb recipes are gaining popularity, including rhubarb salsa, rhubarb barbecue sauce, and rhubarb with roasted meats or fish.

The tartness of rhubarb provides a unique flavor element that can balance the richness of meats and add a refreshing tang to savory dishes. Its versatility is being increasingly explored in modern cuisine.

Use of rhubarb in cooking |

It is the Anglo-Saxons who know best how to exploit its taste treasures: jam, chutney, compote, tart, soufflé, not to mention the savory version, with fatty meats to which it brings a welcome acidity. Rhubarb can be baked, pan-fried, simmered, poached or pureed. It can also be made into a very tangy juice, delicious in cocktails. Take a look at the flavor pairings with rhubarb.

rhubarb juice can very well replace lemon juice in recipes such as for making mayonnaise or vinaigrette or a cake . It is most often seen in jam, compote, pie or in rhubarb butter, but it can also be used in other types of desserts, and even in savory dishes, such as salads.

Culinary qualities of rhubarb: Color and juice of red cultivars |

Crop Diversification Center South analyzed eight cultivars for their culinary qualities. In terms of moisture content, all registered varieties have a moisture content between 92.2 and 94 percent. The pH, or measure of acidity, ranges from a low 4.87 for Cherry Red to a high of 3.94 for Valentine. Sucrose readings average nearly 5 percent across all varieties.

Juice content and red color intensity varied more. The following table lists the varieties with a red color from most intense to least intense and the corresponding juice yield.

Variety from most intense to least intense	Juice yield %
Valentine	76.6
Cherry Red	79.4
Early Sunrise	82.6
Cherry Wine	79.7
Mcdonald	77.7
Canada Red	79.7
German Wine	82.5
Strawberry	81.2

Source: Agdex, August 2002

Effect of different cooking methods on rhubarb polyphenols |

Polyphenolic compounds, such as anthraquinones and stilbenes, from Rheum species have been shown to exhibit diverse bioactivities relevant to human health. The article describes the polyphenolic composition of edible rhubarb (Rheum rhapontigen) petioles and the effects of common cooking methods on total polyphenol content, anthocyanin content, and total antioxidant capacity.

Most cooking methods (rapid simmering, slow simmering, and baking), with the exception of blanching, increased total polyphenol content and overall antioxidant capacity compared to the raw material. Variations in anthocyanin content and total polyphenol content between different cooking methods suggest a balance between two processes: cooking facilitates the release of rhubarb polyphenolic compounds but also induces their degradation.

In general, total polyphenol levels were higher in cooked rhubarb samples than in raw rhubarb samples. The highest concentrations were observed after slow cooking for 30 minutes, followed closely by cooked rhubarb at 20 minutes. Blanching appeared less effective, with polyphenol concentrations decreasing after 20 and 30 minutes, but it is likely that some components were lost as the blanching water was not retained. However, a decrease in total polyphenols was observed.

Liquid chromatography–mass spectrometry (LC–MS) analysis identified more than 40 polyphenolic compounds in raw rhubarb, including anthraquinone, stilbene, anthocyanin, and flavonol derivatives. Cooking had selective effects on the stability of the various polyphenolic compounds. Initially, the yield of all compounds increased, but the relative stability of the anthraquinone aglycones decreased significantly with increasing cooking time. Initial evidence of the turnover of other anthraquinone derivatives was obtained.

Source : Effect of different cooking methods on rhubarb polyphenols, Gordon J. McDougall, Pat Dobson, Nikki Jordan-Mahy, 2009

Rhubarb Juice as a Natural Antibrowning Agent |

To research natural anti-browning agents, rhubarb juice was tested on freshly cut apple slices and found to be effective. Liberty apple slices were treated with various concentrations of rhubarb juice (5% to 100%), and the discoloration rate at room temperature was measured using a Hunter colorimeter. Apple slices treated with the 5% to 10% solution showed browning activity with dL values of 2.3 to 2.5 after two hours. However, rhubarb juice concentrations above 20% effectively inhibited apple browning, with no change in the L value for several hours.

The oxalic acid content of the rhubarb juice analyzed in this study was 334 mg/100 g of juice. Based on this result, the 10% juice contained approximately 0.03% oxalic acid and the 20% juice contained 0.07% oxalic acid. The value of 0.07% oxalic acid in the 20% juice, the approximate minimum concentration required to inhibit browning, is close to the minimum concentration of 0.05% determined in a previous study (Son et al. 1999). Therefore, the anti-browning activity of rhubarb appears to be mainly due to oxalic acid in rhubarb juice. The anti-browning activity was also tested after pasteurization of rhubarb juice (pH 5 4.3) at 80 8C for 5 min. Heat treatment of rhubarb juice did not affect the anti-browning activity on apple slices (p , 0.05). In addition, rhubarb juice was treated with activated carbon to obtain a colorless and odorless liquid. This clear solution was also found to be as active as untreated rhubarb juice (p = 0.05). We conclude that rhubarb juice is a highly effective natural anti-browning agent for fresh-cut fruits and vegetables, and has strong commercial potential because it is easily available, inexpensive, safe, natural, and free from regulatory constraints.

Source : Rhubarb Juice as a Natural Antibrowning Agent, S.M. SON, K.D. MOON, AND C.Y. LEE, Journal Of Food Science, Vol. 65, No. 7, 2000

Rhubarb Measure Conversions |

2 to 4 stalks: 240 ml (1 cup) cooked rhubarb
1 pound of rhubarb = 3 cups chopped rhubarb
3 cups chopped rhubarb = 2 cups cooked rhubarb
15 medium stalks of rhubarb = 6 cups chopped rhubarb (approximately)
Note that these conversions have been rounded to standard measurements.

Cooking Rhubarb Flowers |

An unusual perennial vegetable often appears in our gardens: rhubarb flowers. It's often recommended to remove the flower stalks from rhubarb to prevent it from wasting its energy producing seeds. So, instead of composting it, you could cook it, as is done in the Far East, as an exotic seasonal ingredient.

"The spherical, unopened rhubarb blossoms are considered a delicacy."
Source : U. P. Hedrick: Sturtevant’s Edible Plants of the World, Edward Lewis Sturtevant, 1919

It was after discovering this passage while researching historical books that I became interested in the edibility of floral bouquets. Later, I read an article about a Swiss farmer serving fried rhubarb flowers. That's when I knew I was on the right track. After a few years, more and more gourmets began using floral bouquets in their cooking.

The secret to preparing rhubarb flowers is knowing that the tiny flowers that make up the head don't contain oxalic acid, the substance that makes rhubarb so sour, unlike the flower stalk. The stem is a branched structure that penetrates the head, so you'll never be able to extract it entirely. However, by trimming the most accessible parts, you'll eliminate most of it. Also, be sure to remove the stem leaves, which are probably as toxic as the basal leaves, as well as the papery bract that surrounds the flower head.

The result is still acidic, but oddly enough, without being overpowering. It pairs best with acidic dishes, and you can often omit vinegar or lemon juice to compensate. I find it delicious boiled for four or five minutes with broccoli sprouts, then drained and served with oil and salt on top, without the lemon juice I usually add. It also goes very well with a stir-fry.

Roasted Foie Gras with rhubarb flower and lemon thyme - Restaurant Bord'eau in Amsterdam

Cooking unopened flower blossoms of rhubarb by Forager Chef

Since a flower contains a stem and therefore oxalic acid, even with the greatest care, it is not recommended to consume too much of it. This is also the case with rhubarb stalks, which are more commonly consumed.

Looking for rhubarb recipes? |

Visit the rhubarb recipes section. You will find both sweet and savory recipes as well as how to replace lemon with rhubarb. Compotes, juices, cocktails, drinks, wines, tarts, crisps, sorbets, sweets, dessert, smoothies, poached, braised, side dishes, stuffings, ice creams, sauces, curries, savory tarts, kimchis, ketchups, vinaigrettes, salsas, chutneys, marinades , salads, hot and cold soups.