In case you don’t wish to read further, let me say shortly – all parts of taro must be cooked before eating. Now, grab a cup of coffee and read on…
Not all taro is created equal, unfortunately – aquatic or upland. Edible taro is selected for it’s low oxalic acid crystal content. The lower the content, the easier it is to cook out. Most taros have too much to even cook out, rendering them unpalatable. Oxalic acid crystals irritate soft tissue – which happens to be the primary tissue in your mouth and throat. The effect is akin to having a very bad sunburn in your mouth and throat, along with possible swelling – a serious challenge to those who already have a hard time breathing and a painful inconvenience to the healthy among us.
However, when cooked, edible taro is almost miraculously nutritious and contains easy to digest carbohydrates and is hypoallergenic. So, varieties of taro that are low in oxalic acid crystals were selected over the centuries and perhaps even bred too – there are actually a great many edible varieties out there, much like there are a great many varieties of tomatoes. Hawaii actually has a minority of the edible taro out there, even tho it is what gave taro it’s popularity to the Western world. Taro is grown and eaten all thru Asia, the Pacific and Indian Ocean islands, northern Australia, and even in Central and South America. Most edible taro belongs to Colocasia esculenta, tho in S. and C. America, Xanthosoma taro is popular.
So, for unidentified taros, your mileage definitely will vary. I’ve had people ask me about taro they found growing in a ditch, or growing in an abandoned bed. Is it an edible variety that naturalized, or is it an ornamental that naturalized? I wager that it’s more likely an ornamental that naturalized since they are more commonly grown nowadays and what eventually escapes cultivation. However, many ornamentals were bred from edibles – and some indeed are edible as some of you are no doubt discovering. Nevertheless, ornamental or wild or naturalized edible – caution is highly recommended if you are determined to explore edibility. Even known edible taros that you’re unfamiliar with needs caution until you have had a chance to determine the range of cooking required to nullify the oxalic acid crystals.
However, low oxalic acid crystal content is just the tip of the ice-berg in determining edibility. A big part of edibility is also palatability. You’ve cooked it and determined thru careful testing that the taro can indeed cook out the oxalic acid crystals and you can eat it safely. Now – how does it taste? How is the texture? Some taro can taste like burnt rubber and have the consistency of an inner-tube, for instance. But with careful testing you can select the best from what you have collected and perhaps have a winner – something that has flesh firm enough to cube as table taro (like boiled cubes of potato), or flesh that’s soft enough to easily crush into poi. Something that has a pleasant taste and aftertaste and pleasant mouth-presence. Or it may have leaves that are of high quality in eating. Or it’s stems may be what sets it aside, steamed like asparagus or chopped and boiled. It takes a lot of experimentation to determine the full potential of an unidentified and even identified taro, and that’s why it’s so fun.
Take great care when testing at first. Start with the leaves – they’re the easiest. The best leaf to pick, IMHO, is usually the second one from the bud, perhaps the third too – old enough to be larger, but young enough to be tender and relatively lower in oxalic acid. The young rolled up leaves can be good if cooked and eaten like spinach but it’s generally not large enough to wrap anything in. I always mix a little salt in the water when I boil. Don’t save the water after boiling tho.
Now, for testing… If you boil a leaf, don’t think you have to eat the whole thing – take the smallest nibble, crush it some and let it rest on your lip and wait to see if you get a burning sensation. Baking soda or vinegar will help counter that if you do get the itch. If you don’t get any itch, take another small bite and chew it good, let it rest on your tongue, then spit it out and wait to see if the itch forms on your tongue. If you get itch, gargle some baking soda or vinegar – then boil another leaf for a bit longer and repeat the tests. Even for known taro you almost have to do this because much of the culinary history of taro has disappeared and we’re having to rediscover it. I start off with half an hour. If that’s long enough, then back up, cooking less and less until I find the range where the itch starts – that way you know just how little cooking it needs to get the itch out which will help when you’re cooking this mixed with other ingredients. However, some can even take 45 minutes of boiling – and some will never get cooked itchless. Once you’ve found the proper cooking time for the leaf, cube up a corm and repeat with a cube at a time. A little piece on your lip. If that’s okay, a little bit chewed. Ditto.
If that’s okay and you’ve reliably determined the safe range of cooking for your taro, then it’s safe to move to the next step of experimentation – palatability. Is the corm soft and low in fibers? Crush it and see just how it’s consistency turns out for poi – and explore it’s taste qualities. Bear in mind that poi is often best served with very spicy or salty dishes for many of us. Is the flesh firm? It may be better for cubed or riced dishes. Fibrous? It may be better sliced across the grain and fried into chips. Is it rubbery when hot? Rubbery when cold? Does a little more cooking alter this? A little less? (check for the itch always). Rubbery is not necessarily a good indicator of palatability but some taro remain palatable if still hot and a little rubbery texture can be useful when grinding the taro with a bit of water to make paiai as has been demonstrated with the Kai group of taro. If it’s firm, can it be sliced thin and fried? (taro chips – salted or sugared – yum) Can it be dried and powdered into flour? (taro flour works good in pastries and even pancakes) There’s an endless array of culinary questions you can explore with any taro, known or unknown.
Whatever the case, you’ll want to ensure that the taro you are looking at in those ditches are indeed Colocasia esculenta or perhaps Xanthosoma sp. taro. A few Alocasias are also edible. But there are surely look-alikes out there that may be different plants altogether – so be sure of your identification before performing edibility tests to make sure you don’t accidentally poison yourself. Post pictures of the corm, stem and leaves over at the Taro and Ti Yahoogroup for us to express our opinions, and if you have a local ag-department at your university, see if they can help you narrow down the identification.
MikeV