Water Spinach Splitter

Water spinach (rau muống in Vietnamese, ong choy in Cantonese) is a super popular green vegetable in Southeast Asia and Southern China, where it grows literally like a weed. The tender leaves and tops are boiled and stir-fried. The tougher, hollow stems (about 1/4 inch wide) are resourcefully split so that they're easier to chew.

In the Vietnamese kitchen, the shreds of stems are soaked in water until curly and crunchy. There's just a slight grassy flavor in the stems, which are enjoyed mostly for their nutritional value and texture. Typically, the shreds are lightly dressed with a vinaigrette for a salad or set out as a noodle soup garnish for guests who want to add extra crunch and fiber to their meal. (Eating too much of the stems, however, may lead to constipation.) Indeed, there's little waste when you're feeding lots of people.

A knife is traditionally used to split the stems, but the modern water spinach splitter (dao chẻ rau muống, literally “knife for splitting water spinach”) works much better and saves time. Blogger Jaden of Steamy Kitchen asked about this handy little tool and prompted this posting.

What is it and how does it work?

Dao chẻ rau muống (pronounced “zow chey rau moong”) is a thin metal rod attached to a round plastic top that contains a set of sharp blades arranged like wheel spokes. The entire tool measures about 10 inches long.

To use the splitter, first remove the tender leaves and tops and use them for stir-frying with garlic, etc. Aim for stems that are about 1/4 inch wide. Soak the stems first in water for about 5 minutes to firm them up and make them easier to split.

When you're ready, slide the splitter into a stem and then push the stem through the blades until about 4 inches of split stem protrudes. Then grab the split portion and pull on it to drag the remaining stem portion through the blades. If my description confuses, look on the back of the cute packaging for instructions, such as the ones to the right.

Deposit the shreds in another bowl of cold water and let them soak for 10 to 15 minutes to curl. Drain well before using. The stems may be kept in a zip-top bag and refrigerated for up to 3 days.

If you're old school, you'll notice that using the tool gives you super tight, curly, kinky pieces . The traditional knife method yield results that are more like scallion greens that you'd leave to curl in water for decor. With the splitter, you get a mound of tangly corkscrews that could probably be glued together into a green wig. (Sorry I don't have a photo of the curls.) It's hard to eat the shreds that way or detangle them at the table. Avoid the super kinky by simply cutting the split lengths shorter before soaking.

Where can you buy one?

A water spinach splitter costs a pittance -- a few dollars at most. Ask a cashier at a Vietnamese market to direct you to the aisle where you will find the handy gadget. The cashier often has the gadget nearby or tells someone to get one for you.  At an Asian houseware or cookware store, like MV Trading Company or Kamei in the San Francisco/Bay Area, the splitter hangs on the wall display of all gadgets that includes peelers, thermometers, scissors, etc. When in doubt, ask!

Note: If you're hooked on water spinach, see the water spinach history posting on Vietworldkitchen.com.

Comments

[steamy kitchen]

Thank you! Now I know what to ask for!

[Andrea]

You're welcome. It's a weird, but useful tool. Asian people -- so clever!

[Anh]

I remember this! I haven't seen any Vietnamese groceries here (Mel, Australia) sell theready-made 'rau-muong-che'. My grandma and mother can shred the stems beautifully using a small knife - I can't. I will look for the splitter here. :)

Oh, do you know what my great find of the week is? 'Tuong Ban' (Bean Sauce from Ban Village) - made in US. It tastes very good though, very close to what i had back home. It will go well with steamed water spinach!!

[Andrea Nguyen]

There's pre-shredded water spinach stems in Melbourne? Oh, my, that's quite something. I tried using the knife method and lord it was hard -- like shredding green papaya by hand! We're modern girls so a little help from our gadget friends is fabulous.

I'm going to find that bean sauce you mentioned. It's made here so the markets must stock it. In the 1970s/80s, there was 'tuong cu da' which is quite good as far as bean sauces go. It's hard to prepare good bean sauce because of the particular fermentation cultures that are used in Vietnam, and who knows what else. But I'm cheered to know that 'tuong ban' passes your Hanoian test so I will check it out.

[Anh]

Andrea, I think I wasn't clear on my last comment. Sorry :).

No, there's no pre-shredded water spinach in Mel. Even the veg itself is not very fresh, and the stem is quite tough... I am quite particular on my water spinach, so I normally don't buy it in Mel. What I do is to eat them everyday when I have a chance to go back to Hanoi.

As for the bean sauce, I made a mistake (it must be the afternoon effect). It was 'tuong cu da', not 'tuong ban'. The US product passes my taste test though. It's pretty similar to the bean sauce that my grandma used to make. The US sauce might be a little sweeter, but it doesn't bother me...

[Andrea Nguyen]

Anh, there's not a decent supply of rau muong in Melbourne? Why not? With all the Asian people living there, there should be some farmer growing the stuff. Don't the Cantonese, Thai and Malay people miss it too?

Ah, tuong cu da -- that is good stuff. It is a bit sweet, the stuff made here. They carefully guard the secret sauce ever since they started producing it in the 1980s. I haven't had it in a while and will revisit it.

So you enjoy it as a dipping sauce. Do you mix it (pha) with anything or eat it straight? How else do you use the sauce. Decades ago, my family used to serve tuong cu da with thit bo nhung dam (thin sliced beef (eye of round), briefly dipped in acidulated water). It's been so long and now you have me thinking of it again...

[Anh]

Andrea, I am just a bit picky with the water spinach, that's all. The products here are quite tough, so I normally buy something else instead.

As for tuong cu da, my dad and I normally serve it straight from the bottle with fried tofu and steamed veg. You can add a bit of freshly sliced chili, too. My mom and sister can't stand the smell so they opt for fish sauce.

A great way of using tuong cu da is in fish braised in caramel sauce (ca kho). Just make it as per normal, but season with tuong cu da instead. Catfish is the best for this but my grandma also uses eels. This is the only way my mom and sister enjoy tuong cu da. And my dad and I are of course crazy over it.

[Andrea Nguyen]

So you'd use tuong cu da bean sauce instead of nuoc mam fish sauce to flavor the catfish kho with the caramel sauce? That sounds good. Funny that your mom and sister find the earthy pungency unbearable, when compared to fish sauce. The bean sauce does have a slight compelling, sour-savory quality.

I once had an unopened bottle for a little too long and it kind of overflowed in my pantry. The clean up wasn't bad. Best to store it in the fridge. I don't think it's sealed well like other condiments.

[kelly]

I need to know if you can juice rau muong i usually use spinich but id like to try something knew with good health benefits and no contamination.

[Andrea Nguyen]

Water spinach (Ipomoea aquatica) isn't botanically the same as regular spinach (Spinacia oleracea). Vietnamese people juice a few kinds of leafy greens (e.g., pennywort) but water spinach isn't one of them. You could certainly try but I don't know what the results would be like.

[piccola]

this is an interesting tool. we usually just chop them all up and stir fry with chili. i'll try splitting the stems next time. :)

[Covey]

Hi,

My mom and my aunt use Tuong Cu Da with a couple of tablespoons of Peanut Butter and some sugar. Is it best to taste out of the bottle or are these other ingredients ok? Plus, do you boil it or pour and use right out of the bottle?

Thank you

[tommyng79]

Hi,

Does anyone know how to make tuong cu da?

[Andrea Nguyen]

Tommy, I was kinda thinking of that myself yesterday. How'd you read my mind? I don't know how to make it but will put it on my to-do list this summer. I've gotten a terrible stomach ache from the Tuong Cu Da bean sauce sold at the Vietnamese markets. It's hard to tell how old it is. . .