Steaming vs. boiling vegetables

[lperry]

When it's too hot in the kitchen for heating up the oven and roasting them, I steam vegetables. They keep their color, and, according to nutritionists, they retain more nutrients. I'm guessing (?) that flavor is retained as well.

As an example, I was recently informed that boiling potatoes is a no-no in Ireland. Steam is the way to go. A quick experiment yielded great flavor and much nicer texture than boiling, and it only took twenty minutes in my big steamer pot.

I'm sold on steaming - less water, less energy, less heat in my summer kitchen. So here's my question. Why boil? Why even blanch instead of doing a quick steaming to tenderize and kill the pesky enzymes? I have been told (perhaps erroneously?) that boiling is taught in culinary school. Is it a time saving measure, or is it just one of those things that people are taught? In a commercial kitchen is it easier to have a big pot boiling on the stove than a steamer that could boil dry? Or is there a flavor/texture issue? Am I even in the ballpark? Enquiring minds want to know.

-Linda

[RyuRiFanatic]

Hm, interesting. I've never actually thought about this during school and now you have me thinking. But I guess on top of my head, the first reason that comes to mind is speed. I think I'll ask one of my chef instructors when I visit one day, hope I don't get a weird look from them .

[carswell]

While I often steam vegetables, I find there's at least one situation where boiling gives better results: when the cooking stage is the best time for the vegetable to be salted or flavoured with another ingredient. For example, new potatoes cooked in their jackets taste better when they are "deep" salted by being boiled in salted water; salting them afterwards doesn't produce the same results. And when making those potatoes to go with fish, I often flavour the cooking water with a sprig or two of fresh dill, which you can't do when steaming. I also prefer boiling for vegetables to be used in a salad (e.g. green beans vinaigrette); again, I think it's a question of deep salting. That said, in most other situations, steaming gives superior results. In fact, it's the way I usually cook potatoes for mashing, since salt and flavouring agents can be easily be added after they're cooked.

[lperry]

I think I'll ask one of my chef instructors when I visit one day.

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Please do. I've always wondered about this.

Carswell, I've put fresh herbs in steaming water with good results. I didn't think about the salting angle. Can the salt get fully incorporated before the vegetable is overcooked?

[carswell]

Carswell, I've put fresh herbs in steaming water with good results.

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The once I tried it with the dilled new potatoes, I was underwhelmed with the results. What flavourings and vegetables have you used?

I didn't think about the salting angle.  Can the salt get fully incorporated before the vegetable is overcooked?

Certainly it can in something like potatoes, which cook for 20 minutes or so. And my impression is that boiled green beans require a less salty vinaigrette than steamed beans do. But I haven't done any side-by-side testing.

Looks like an opportunity here. How about we and anyone else who's game do a virtual test kitchen?

[lperry]

I've used rosemary and thyme before with beans and potatoes with good results, and also lemon juice with artichokes. Some lemon flavor came through and I had no browning problem. All these are pretty strong flavors, and dill tends to be delicate. Maybe that's the difference.

I'm up for the boil vs. steaming test kitchen challenge. Choose your vegetable!

I'm not sure if I can get good beans around here right now. I vote for potatoes because then I can make gnocchi.

[helenjp]

I steam root vegetables not only in my steamer but in the slow cooker and the rice cooker. In the latter cases, they don't need any water at all, they will steam in their own water content, and I rub a little salt into them before they start cooking.

As for leafy vegetables, I was warned that certain vegetables have a high enough mineral content to be a risk to people prone to kidney-stones. That suggests to me boiling was the tastiest and safest method of cooking in times when people gathered slow-growing wild vegetables with their more nutrient-laden foliage, rather than quickly-grown vegetables grown with superadequate water supplies - boiling not only tenderizes tough fibers with higher temperatures, but leaches out and breaks down bitter or toxic substances.

If I steam spinach, I sometimes notice a faint mouth-puckering astringency which I assume comes from residual oxalic acid???

[carswell]

I'm up for the boil vs. steaming test kitchen challenge.  Choose your vegetable! 

I'm not sure if I can get good beans around here right now.  I vote for potatoes because then I can make gnocchi.

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I'm game for potatoes, though I might also give green beans a whirl since they're still in season up here in the Great White North.

Do you have access to new potatoes? I'd love to test them with dill.

How about a test of either new potatoes or stratchy spuds (russets? Yukon Golds?) with more powerful flavourings? Garlic? Bay? Rosemary? Lemon? Any or all of the above?

What's your standard spud for gnocchi? We could use those for the salt test.

[russ parsons]

fortunately, the world of cooking is broad enough that we don't have to choose between techniques. they both work essentially the same (moist, constant heat at about the same temperature), except that in boiling there is an exchange of liquids (and therefore flavors) between the thing being cooked and the liquid it is being cooked in. That doesn't happen with steam (except with very minor exceptions). steam things when you want the flavor of the ingredient to be as vibrant and pure as possible. boil things when you want the flavor mellowed or enhanced by other flavors. use them both.

[lperry]

OK, I'm back from the market with the best produce, and I've got a bag of small new potatoes. I thought I would steam and boil with herbs and salt. I have no dill and saw no dill at the market. I'll probably go with thyme. Sound like a plan?

Helenjp, you have a good point about the greens. I know that pokeweed is boiled several times before it can be eaten. It's supposed to be a spring tonic but it has toxic components that need to be leached out. This week I've been asking people about how they cook their "greens" and most Americans stew them in a pot and keep the liquid for mopping up with bread. Among members of my family, that "puckery" quality is much sought after - the bitterness is desirable, although it's a different compound in mustards than in spinach. Asian people I spoke with pan "fry" greens with a little oil. Europeans boil, but they tend to cook spinach and chard over collards, mustard, bok choi or tat soi. I couldn't find anyone from India this week. I wonder if boiling is more common with greens that make oxalates instead of all those nice members of the mustard family.

Russ, I realize both are useful techniques, I just always wondered why chefs tend to boil things so much. It seems like a terrible thing to do to a really nice vegetable. I'm formulating a hypothesis that it is a holdover from the European cooking techniques that dominate in Western food culture. But this is probably my anthropological training coming through as bias. Thoughts? Anyone?

[russ parsons]

I just always wondered why chefs tend to boil things so much.  It seems like a terrible thing to do to a really nice vegetable.  I'm formulating a hypothesis that it is a holdover from the European cooking techniques that dominate in Western food culture.  But this is probably my anthropological training coming through as bias.  Thoughts?  Anyone?

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i think that is a very interesting thought. i've got two more possibilities, one practical, one aesthetic: 1) it's easier to maintain a big pot of water at a boil for blanching than to have to constantly be refilling the steamer (sounds paradoxical, but since a steamer potis always at least half basket and headspace for cooking, it makes sense to me). 2) Western cuisine came relatively recently to the idea of fresh, vibrant flavors. things have always been "cooked." in fact, look at some old chef books and they blanch the vegetables in stock. not a bad idea, but just a very different flavor.

i remember a food anthropologist crediting the asian emphasis on steaming (and wok-frying and other quick-cooking methods) to a shortage of fuel for long-burning fires. don't know what the citations are, but "sounds true."

edit for recipe: if those are really good little potatoes, here's what you do: steam (or boil) them until they're tender, then toss them in a bowl with some room temperature (not cold, not melted) butter and some fleur de sel. thyme will be great. the butter melts slightly, but forms a kind of napping sauce on the potatoes. unbelievable.

Edited August 24, 2005 by russ parsons (log)

[SuzySushi]

I wonder if boiling is more common with greens that make oxalates instead of all those nice members of the mustard family. 

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More common? Maybe not. Common, yes. Another plant high in oxalic acid is taro leaves, used in Hawaii as a spinach-like vegetable. It's either boiled and the first water discarded, or cooked for a long, long time.

Anthropologically speaking, I don't think that steaming was a part of most European peasant cultures, where foods got cooked by placing them in a pot of boiling water.

[helenjp]

lperry, the "mouth-puckering" I'm thinking of isn't from sharp or bitter flavors, but some reaction that dries saliva up...chewing a mouthful of greens in a suddenly dry mouth is definitely something I want to avoid.

Japanese cooking boils where Chinese cooks often steam. Even my Chinese friends nowadays are skeptical of the Japanese reliance on boiling. On the other hand, traditional Japanese food does involve a lot of bitter leaf/stem vegetables...

I wonder why some cultures find bitterness appealing, while others don't?

[Shalmanese]

Another question, if your steaming, why not steam in the microwave? The microwave seems like the perfect mechanism for steaming because it can penetrate food and steam from the inside. This means you achieve higher temperatures and use less water and take less time. So more nutrients are preserved, the enzymes are destroyed faster and the food in general deterioates far less.

Apart from the inherent prejudice that the west seems to have against microwaves for anything other than TV dinners, why not use the microwave?

[kjohn]

Another question, if your steaming, why not steam in the microwave? The microwave seems like the perfect mechanism for steaming because it can penetrate food and steam from the inside. This means you achieve higher temperatures and use less water and take less time. So more nutrients are preserved, the enzymes are destroyed faster and the food in general deterioates far less.

Apart from the inherent prejudice that the west seems to have against microwaves for anything other than TV dinners, why not use the microwave?

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I boil if it's a leafy green I'm working with. I steam almost everything else. As for the microwave, it's actually a great way to steam vegetables. My father bought a microwave steamer when I was a kid and I've been partial to steaming vegetables ever since.

[lperry]

The microwave has gotten some bad press lately because a few studies have shown that the very high temperatures that it creates actually destroy nutrients. I stopped steaming in the microwave after I read this, and I'm waiting for someone to do further studies on it. The first vegetable tested was broccoli, and new studies have shown that boiling or steaming can also kill the anti-cancer compounds if you cook for too long. So the jury's still out, I guess.

Helenjp - that puckery feeling is the oxalic acid. You may be sensitive to it and can taste it in small amounts.

As to the bitterness question, I was looking at the bitter melon in a store once and asked the Indian woman who was choosing some about it. She told me that the bitter quality is highly prized and bitter melon cleanses your blood. I got a little mini-course on bitter melon from her, and from this and some other people I've talked to, I'm going to guess that the bitterness is an acquired taste, but those who like it appreciate it because it is evidence that your food is doing what you want it to do in terms of your health.

[lperry]

OK, here's the report on the potatoes.

These were new potatoes, about 3 cm in diameter. I'm guessing they are Red Pontiacs since that's pretty much what everyone grows around here.

I boiled with a handful of salt and several sprigs of thyme, and then steamed with the thyme thrown into the water. I tried the boiled potatoes first. The pretty red color had turned dark, but the texture was good. The potatoes were salted through, although I did add a sprinkling more of salt, and they had an herbal flavor.

The steamed potatoes were not salted, and the herbal taste was more delicate, almost like a thought, but it was present. The steamed potatoes took a few minutes less to cook, had better color, and a fluffier texture. Strangely, when I tried the steamed potato and then went back to the boiled, the boiled tasted sort of waterlogged, like the cells were closer together or it had thickened in texture somehow. I don't really know how to describe it, but I'm sure it has to do with more of the starch gelatinizing in contact with water. It really was fine until I tried the other, and then it didn't seem quite so good.

I'm guessing that these were not very fresh since they didn't have really good flavor. The steamed potatoes had more "potatoey" flavor than the boiled, though. I broke them all open, covered them with pesto, and had a nice meal. When I get some of the really tiny fresh ones from the farmer's market or my Grandmother, I'll do the butter/fleur de sel treatment.

[devlin]

How about baked or grilled? Or is one of the goals not to heat the oven? I far prefer some things steamed (broccoli, for example), and I'm frankly having a hard time thinking of one vegetable I prefer boiled, not even potatoes.

Edited August 25, 2005 by devlin (log)

[Hiroyuki]

Even my Chinese friends nowadays are skeptical of the Japanese reliance on boiling. ...

I wonder why some cultures find bitterness appealing, while others don't?

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Your comment reminds me of this thread, which I started in the Japan Forum:

http://forums.egullet.org/index.php?showto...&hl=subtraction

[helenjp]

lperry. thanks for reporting on your experiments. The texture of the boiled potatoes could be affected by the higher temperature as well as the direct immersion in water.

Just curious...did you put the potatoes in cold salted water and bring them to the boil, or add them to boiling salted water?

For greens, I've had good results when boiling them with a little oil as well as salt added to the water. I speculate that maybe it's just the coating of oil, or maybe the oil layer prevents the boiling water from cooling...I don't know.

[carswell]

Thanks for the report, lperry. Am planning a three-part test kitchen for this weekend. Will post notes so we can compare.

Just curious...did you put the potatoes in cold salted water and bring them to the boil, or add them to boiling salted water?

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I experimented with this a few years ago. Here's my report.

At the corner farmers' market, I selected twelve new-crop, white-skinned new potatoes of more or less equal size, slightly larger than a golf ball.

After scrubbing all 12, I put six in a 1½-quart saucepan, covered them with cold tap water by about an inch and added 2 teaspoons coarse sea salt. Then I filled a 2½-quart saucepan with cold tap water and added a generous tablespoon of coarse sea salt. I put a cover on the 2½-quart pan but left the 1½-quart pan uncovered.

I sat both pans on the small burners on my electric range. I turned the heat under the small pan to high (9) and under the large pan to maximum (10), and set the timer.

The water reached a full boil in the small pan after 11 minutes (11') and in the large pan about half a minute later (11'30"). At that point, I dropped the other six potatoes in the large pan, left the heat on max until the water returned to a full boil (about 20 seconds), and then turned the heat down to 8½ on both burners.

After eight minutes (19'), I removed a potato from each pan and sliced them in half. Neither was done, but the cold starting water (CSW) potato was more cooked than the hot starting water (HSW) potato, especially in the centre.

Five minutes later (24'), I repeated the procedure. The CSW potato was nearly cooked. The HSW potato still had a mealy centre.

Four minutes later (28'), the CSW potatoes were done. I drained them, returned the pot to the burner and shook it to evaporate any surface moisture. Then I set the pan aside with the cover slightly askew while the HSW potatoes finished cooking.

Four minutes later (32'), the HSW potatoes were done; they had been cooking a total of 21 minutes. I drained and dried them. Then I compared the two.

The differences were small but detectable. The CSW potatoes had a slightly more consistent and creamier texture. The contrast between the centres and the surface of the HSW potatoes was more pronounced; they also seemed a tiny bit mealier.

To see if I could detect a difference blind, I had my bemused neighbour serve me a CSW potato and HSW potato on separate plates, without telling me which was which. It was hard deciding but I eventually chose "A" as the HSW potato because its skin was a bit less fine and the flesh just under the skin a bit more mealy. It turned out I was right. But I doubt whether, had I been served a single potato blind, I would have been able to identify it as CSW or HSW.

(FWIW, my neighbour said that, although she found the texture of the CSW potato slightly waxier, she would be happy eating either one.)

Finally, in a possibly vain attempt to determine whether the CSW potatoes' extra cooking time (while the HSW potatoes finished cooking) had skewed the results, I tasted a potato from each batch after they had completely cooled. Once again, the CSW potato seemed marginally better.

Contrary to my fears, the skins of the HSW potatoes remained intact. However, two of them split after I pierced them at the end to determine doneness. This didn't happen with the CSW potatoes.

Bottom line: the CSW potatoes win by a hair. They also took less time to cook and used slightly less water and salt. Of course, the time difference would have been all but eliminated if I had heated the HSW in an electric kettle instead of on the stove.

On the basis of this test, I don't think anyone should feel obliged to change their potato-boiling procedure. But I wonder whether the minor differences wouldn't be magnified if you were boiling larger potatoes.

[lperry]

Just curious...did you put the potatoes in cold salted water and bring them to the boil, or add them to boiling salted water?

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I started the pots of water while I washed the potatoes, so the steam was steaming and the water was boiling when I put the potatoes in.

I look forward to hearing from Carswell!

[hjshorter]

Apart from the inherent prejudice that the west seems to have against microwaves for anything other than TV dinners, why not use the microwave?

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I boil if it's a leafy green I'm working with. I steam almost everything else. As for the microwave, it's actually a great way to steam vegetables. My father bought a microwave steamer when I was a kid and I've been partial to steaming vegetables ever since.

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I never seem to get an even result by microwaving. I usually boil. I find it easier to keep track of the timing and not overcook the veg.