Trai Au

January 8th, 2008 by: joshua

Trai Au Bull Head

I found these in the produce section of Fubonn and had to have them. Of course, I had no idea what they were or what to do with them, but I trust in the powers of the world wide internet to see me through. At only $1.48/lb they’re a bargain even if they just end up as part of my voodoo death necklace. The label identifies them as “Bull Head / Trai Au.”

Trai Au Bull Head Fubonn supermarket produce label

Clearly a Vietnamese name but google wasn’t all that helpful. We see two results in English and several in Vietnamese. I can’t read the latter and none of them look like recipes anyway so I concentrated on the former. One blogger also found them at Fubonn and didn’t have many hard facts to offer. The other found them at a market in Vietnam. He claims that the market lady told him that they were Trai Au and explained that they were Lotus Roots. Obviously he misunderstood. I know a lotus root when I see it and these things aren’t the least bit root like. I think they are thorns because they resemble the ant infested thorn bushes we fought our way through while hiking on Isla Providencia.

Cheyenne and I have prowled the markets of Vietnam ourselves and don’t recall having seen anything like it. Either they were out of season or they aren’t too common. Of course, we could have missed them while we were distracted by the live scorpions or the imitation cockroach extract (I kid you not, it’s called Ca Cuong).

Trai Au Bull Head cracked open

They turn out to be pretty hard to get open. Forget about doing it by hand because of those spiky ends. A hammer works well but it doesn’t seem possible to remove the meat in one piece. I hit them until they break open then pry the insides out with a knife.

They are bland and mostly tasteless but very slightly bitter with the texture of mature coconut meat. I still don’t know what to do with them. It doesn’t seem worth the effort to eat them as nuts and I can’t imagine cooking with them either.

5 Comments on “Trai Au”

  1. Bozo says:

    Here’s a link to more of your thorns.

    We were give similar ‘stuff’ by the village kids on isla Roatan (Honduras). The shape is quite different… but the hard shell and white insides are similar. I think what we had were pods from a jungle Acacia. You had to crack them open with a rock or hammer… and then picked the white, fluffy material from around the seeds.

    The filling had a very odd texture… light, dry, but melted in your mouth… maybe like a merengue… as I recall, they tasted vaguely like vanilla custard.
    (which is what the kids were after).

  2. joshua says:

    Acacia was what I was thinking of but they turn out to be unrelated.

    A cross post to chowhound yeilded an answer. These are Trapa bicornis also known as Bat Nut, Devil’s Pod, and Ling Jiao. It’s an water plant related to the water chestnut.

    Toxic when eaten raw. Ooops. Take those away from the pregnant lady. We’ll try boiling them to see if they taste better. We didn’t eat very much (less than one nut).

    I did some research on Acacia as well and it’s a pretty interesting plant. The leaves and bark contain tryptamine alkaloids including DMT (some species more than others). Whether you would get any from eating the nuts is hard to tell from my brief reading. In any case the DMT would be metabolized unless you mixed in some sort of MAO inhibitor.

  3. Julie says:


    We bought a couple of theses at the rainbow grocery in san fransisco. (we didn’t attempt to open them or eat them though). I gave one to my brother as a birthday present and the other is propped up in the cabin as a good luck charm…let me know what it tastes like…it could be the ‘last emergency’ rations on board.

  4. Jill Douglass says:

    The photo makes them look like bat shaped licorices. Those I would eat.

  5. Sasher says:

    I’m not sure if this Bull Head/Trai Au falls under the fruit or vegetable category but you must boil it first in order to be able to open it with your bare hands. You should boil them for 20-30 mins and then let them cool down. Once they have cooled down, you should be able to open them and eat them. They have a very light nutty flavor. Not bitter at all once cooked.

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Cheyenne Weil, Joshua Coxwell