Taro / Colocasia - Leaves & Stems

[Taro (Polynesian); Kalo (Hawaiian); Colocasia (Rome); Kolocasi (Cyprus); Ocumo, Cocoyam, Madumbi, Nduma (Africa); Macabo (Cameroon); Khoai mo, khoai so (Vietnam); Laing (Philippine); Dasheen, Eddoes (Caribbean); Malanga cabeza, Malanga islena (Cuba); Arvi, Colocasia (India); Talas (S.E. Asia); Dalo (Fiji); Cara (Brazil); Calaloo (Caribbean, leaves only); Yautia (Puerto Rico); Colocasia esculenta]

Taro leaves are, of course, grown wherever Taro Corms are grown (see our Taro / Colocosia page). They are edible, and are cooked and eaten similarly to Spinach in most of those regions. They do need more careful treatment than Spinach as their content of Oxalic Acid and Calcium Oxalate are much higher.

Note that Taro Leaves can easily be confused with Malanga Leaves which have much lower Oxalate content. They are easy to tell apart. The stem of a Malanga leaf joins the leaf right at the point of the "V" notch. As you can see from the photo, Taro leaf stems join the leaf several inches inward from "V" notch.

While these leaves have been pretty much unavailable in North America, they are now showing up in Philippine markets here in Los Angeles (2017), and are selling very well when they appear. The photo specimens, purchased from a Philippine market in Los Angeles (Eagle Rock), were 15 inches long. The leaves were typically 10-1/2 inches long and 7-1/2 inches wide. A 1.82 pound (29 ounces) bunch yielded 14 ounces of leaves (48%) and 15 ounces of stems. Cost was 2017 US $5.99 / pound.

More on Arums.
See also Taro / Colocasia Corms.

Fresh Taro Leaves

[Gabi (Philippine)]

Young taro leaves are commonly used in the cooking of West and Central Africa. They are also used in Hawaii (Luau) and other Pacific islands, and especially in the Philippines. Taro leaves should be used carefully and not to excess, as they are high in Oxalic Acid and Calcium Oxalate (see Health & Nutrition). They should always be wet cooked and consumed with plenty of other ingredients.

Buying:

Taro leaves are not commonly available in North America, but are becoming more available in the Philippine markets here in Los Angeles. If you live in a tropical or subtropical region, you can easily grow your own leaves and stems by planting the widely available corms. You must keep the soil they grow in very wet to keep the stems from wilting and the leaves from drying out.

Prep:

This is usually just rinsing and cutting. For the recipes I've made, I first remove the stems. Some references say to cut well around the stem attachment point and cut off the tip of the leaf. Next I make a cut from the stem attach down so they will lie flat. I pile up a number of leaves, then cut them completely in half from the "V" notch. I Then cut both halves in half lengthwise to produce 4 strips. I pile these up and then cut crosswise about 3/4 inches wide or however works in the recipe.

Cooking:

Taro leaves must be wet cooked to dissolve and dilute the acid to a harmless level. No amount of cooking will remove or significantly reduce the calcium oxalate content, but it is not much absorbed by the body. Cooking times are usually quite long, 45 minutes to an hour, not just to disarm the Oxalic Acid, but also because the leaves are pretty tough and need that much time to be tender.

Subst:

Spinach is the usual recommendation, but I recommend Swiss Chard (white stemmed variety) which will produce results much closer to Taro Leaves in both texture and cooking properties, but in much less time. Collard Greens may also work well, with longer cooking. African cookbooks in English often call for Spinach, but they really mean Colocasia (Taro). Spinach is a cold climate vegetable not available in tropical Africa.

Dried Taro Leaves

[Pinatuyong Dahon ng Gabi (Philippine)]

Dried Taro Leaves are available in Philippine markets. Many Filipinos prefer them for availability, storability, and under the false presumption that sun drying reduces the Oxalate content. Oxalic Acid is not volatile and even baking won't drive it off - it's long wet cooking that does the job. Of course appearance will be different from fresh leaves because they will be quite dark, and the flavor will be a bit different due to drying.

Buying:

Most Philippine markets will have these. The photo specimens are "Tropics" brand and found bagged in the lightly refrigerated cases. 2017 US $2.69 for a 4 ounce package. Product of the Philippines.

Prep:

These should first be soaked. Unfolding them to cut like fresh taro leaves would not be practical, so after soaking they are just chopped fairly small.

Cooking:

Long cooking is still in order, similar to fresh leaves, to disperse Oxalic Acid and tenderize the leaves. I find about half an hour is adequate, but longer wouldn't hurt.

To make the rough equivalent of 1 pound of fresh leaves (stems removed) you would need about 2-1/2 ounces of dried leaves. 2 cups of dried leaves moderately packed is about 1-3/8 ounces, so you'd need almost 4 cups to be equivalent to 1 pound fresh.

Taro Stems

Taro stems are called for by some recipes in India (Colocasia stem, usually fresh) and Korea (To-ran, fresh and dried). They contain both soluble Oxalic Acid and non-soluble Oxalates in various proportions, but figure about half and half. They are not as bad as leaves, but should still be used cooked like leaves and eaten with plenty of other ingredients.

Buying:

Dried taro stems are available in Korean markets in North America. The photo specimens were purchased in Los Angeles at 2105 US $3.49 for 5 ounces ($11.17 / pound). Most stems were about 12 inches long. Fresh stems are now occasionally available attached to leaves in Philippine markets here in Los Angeles. Otherwise, if you live in a tropical or subtropical region you can easily grow your own.

Cooking:

Dried stems should be soaked overnight, in a couple changes of water, and preferably given a short boil afterwards. This will remove much of the soluble oxalic acid. Nothing can be done about the non-soluble calcium oxalate, except to bury it in other ingredients. These stems are very different from other Korean dried stems, as they are soft and spongy. They tend to puff up a lot when boiled or steamed, but quickly shrink back when cooling.

Yield: One ounce of dried stems will be 5 ounces after soaking overnight.

Giant Taro Stems

[Bac Ha (Viet - South and U.S.); Doc Mung, Roc Mung (Viet - North); Indian Taro; Hasu-imo, Ryukyu (Japan); Manto de Eva (Chile); Colocasia gigantea]

Not exactly Taro, but often sold as "Taro Stems" or "Colocasia Stems". This plant is native to Southeast Asia, and is thought to be a natural cross between Alocasia macrorrhizos (Giant Elephant Ear) and Colocasia esculenta (Taro). The stems are eaten as a vegetable in Southeast Asia, particularly in soups in Vietnam, and in Japan. The root corms of this species are fibrous and inedible, and the leaves are not particularly edible either. Details and Cooking.

Health & Nutrition

Disclaimer: information in this section is from publicly available literature, and can not be taken as medical advice. For medical advice, refer to licensed health care practitioners.

Taro leaves are highly nutritious, with a good spread of vitamins, minerals, protein and antioxidants. They are also well known for a negative: Oxalic Acid and Calcium Oxalate.

There are a whole lot of shrill articles on the Internet about the danger of consuming Oxalates (a designation that usually includes Oxalic Acid). Reputable medical research shows this to not be the case except for a very few people who have particular genetic defects, or people on crank diets, or taking supplements in excess, particularly vitamin C, or who eat high Oxalic Acid plants to excess.

Oxalic Acid:

This element is soluble in water. It is more sour than acetic acid, but will be reduced greatly by cooking in hot water. Disposing of the cooking water greatly reduces the Oxalic Acid in the food. Absorption into the body by digestion depends on the condition of the gut. For people with healthy digestive systems, much of it is absorbed by bacteria, and it is also expelled in urine. Taking antibiotics can increase problems by reducing gut bacteria, and people prone to kidney stones should minimize consumption of high Oxalic Acid foods. For most people the health benefits outweigh the negatives.

Oxalic acid does combine readily with metals such as Calcium, Iron and Magnesium, making them unavailable to the body. Again, there are a lot of shrill Internet articles warning about this, but reputable medical research has shown it to be a non-problem for people getting adequate nutrition. Some recommend that if you are eating a lot of foods high in Oxalic Acid, to combine them with foods high in Calcium. The Oxalic Acid can combine with the Calcium in the digestive tract to form Calcium Oxalate, which is not much absorbed into the body. Actually, leafy greens containing Oxalic Acid usually have plenty of calcium as well.

Calcium Oxalate:

This salt is largely insoluble in water, so is not removed by washing, soaking, or boiling, and does not contribute to sour taste. It is included in many plants, such as Spinach, Chard, Beet Greens, and even Broccoli. This is not usually a problem, because the crystal shape is usually blunt, and very little is absorbed in digestion.

In Taro Leaves, Stems and Corm Skins, and sometimes the corms themselves, the calcium oxalate is in the form of very sharp needle like crystals called raphides. These crystals are specifically designed for defense, and designed to inject damaging substances when they penetrate mucous membranes, resulting in extreme discomfort, swelling and pain. Many people shy away from fresh leaves for this reason.

These raphides are not soluble in water, but are soluble in Hydrochloric Acid (stomach acid). They are not soluble in Acetic Acid (vinegar), but are soluble in Citric Acid (lemon / lime juice). Apparently they can be broken up by long cooking, because Taros riddled with them are eaten after a long (sometimes hours) boiling.

How dangerous these crystals are depends on plant cultivars. Domesticated cultivars are generally much less of a problem than wild plants. In the Philippines, dried Taro Leaves are most used, for availability, storability, and under the presumption that sun drying removes the Oxalates. This is not at all the case, as Oxalic Acid is not volatile. Even baking doesn't drive it away, it is wet cooking that removes Oxalic Acid, from dried leaves as well as fresh.

Reduction of Oxalates is generally done by extensive boiling and changing the cooking water. Some Taros, like Giant Swamp Taro, take a whole lot of boiling to be safe to eat. In some plants, the raphids become encased in starches during cooking and cause no problem. It is best to avoid the parts of the plant that include raphides, and especially avoid wild plants.

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