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 in most of those regions. They do need much different treatment, because the Oxalic Acid and Calcium Oxalate content can't be simply peeled off as it can with the corms.
While these have been pretty much unavailable in North America, they are now showing up in Philippine markets here in Los Angeles, 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 -
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. Next I make a cut from the stem point down so they will lie flat. I pile up a number of leaves, then cut them in half from the point down, then both halves in half similarly 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 the sharp needle-like oxalic acid crystals 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.
Collard Greens may also work well. African cookbooks in English always
call for spinach, but they really mean Colocasia. 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, and under the false presumption that sun drying reduces the Oxalic Acid 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.
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
Not actually 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 and Colocasia esculenta
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.
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, which frightens people and prevents them from being more widely used.
Unlike spinach and other high Oxalic Acid plants, Taro (and the rest of the Arum family) contain it in a particularly dangerous form. Even a single bite of these raw can cause discomfort, swelling and pain. Many people shy away from fresh leaves for this reason. In the Philippines dried Taro Leaves are most used, for availability, and under the presumption that sun drying removes the Oxalic Acid. This is not true, as Oxalic Acid is not volatile, even baking doesn't drive it away. It is wet cooking that disarms the Oxalic Acid, with fresh leaves as well as dried.
There are a whole lot of shrill articles on the Internet about the danger of consuming Oxalic Acid and Oxilates. Reputable medical research shows this to not be the case except for a very few people who have a particular genetic defect, 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 acid is included in many plants, such as Spinach, Chard, Beet Greens and even Broccoli, where it provides sourness, but is not a direct threat. In Taro Leaves, Stems and Corm Skins, the oxalic acid is in the form of very sharp needle like crystals. Should raw taro be eaten, these crystals will penetrate mucous membranes, and the wound will be exposed to the very powerful acid the crystals are formed from. This results in extreme discomfort, swelling and pain.
Oxalic acid is, however, soluble in water, thus the sharp crystals are dissolved and the acid dispersed by hot water in wet cooking. It is too dispersed to reform crystals, in the food or in the digestive system. It is easily absorbed into the body by digestion, but is also easily excreted in urine. Only under unusual conditions is it a problem.
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 insoluble in water and highly stable. It is not removed by soaking or even extended boiling, however, it is not readily absorbed by the body. Though kidney stones are often composed of calcium oxalate, that oxalate is produced in the body from oxalic acid and calcium. Taro may contain other non-soluble salts, but not in notable amounts.