Sunday, October 17, 2010

Cutting through the slime around "okra leaves"

During my series on unusual greens in 2006, one of the entries focused on what I had been told were "okra leaves." Two astute commenters, however, pointed out that the identification I have been given by the farmer was probably incorrect. In the first comment, Katie, noted that some farmers call leaves from the jute plant "okra leaves" because they produce okra-style slime when cooked. In the second comment, beautdogs, pointed out that the leaves in my post look nothing like okra leaves and so I had been misinformed (and a bit negligent in my research).  I didn't think about the post for a long time until a plant-obsessed friend saw the post and decided that she had to figure out exactly what this plant was.

Her research confirmed Katie's comment: the plant was jute, specifically, Colichortus olitorius. Jute is well known as a source of fiber for cloth and rope making, but it also has culinary and medicinal uses. The Center for New Crops & Plant Products at Purdue University reviews the characteristics and uses of jute Colichortus olitorius; the University of Melbourne's plant name database contains a list of names for the plant in various languages.

A few weeks after she confirmed the identity of the plant, my friend send me the following report (quoted and slightly edited with permission):
The Vang Family stand [at the Berkeley Farmers Market] was very crowded when I walked into the market, so I didn't stop to check out what they had. On my way out, I stopped to pick out some okra from them and happened to be there just as Mr. Vang went into his van and took out a giant bag (garbage bag size) of Corchorus olitorius for a Middle Eastern woman (possibly Egyptian?). She bought every last bit of the stuff. Naturally, I wandered over with questions.

(a) She confirmed that this Corchorus olitorius is molokhiya. She uses some fresh and the rest is dried for later.

(b) They both agree that it is slimy/sticky when cooked.

(c) Mr. Vang also wrote down the Hmong name. He spelled out the words "npia nplaum" which he pronounced something close to "blia blau." Hmong pronunciation and spellings are pretty convoluted (more at Wikipedia).  The word "nplaum" (pronounced "blau") means sticky. He said the two words translate to sticky leaf. I couldn't find the word npia or npla in various online dictionaries or discussions, but all clearly confirm that nplaum means sticky. (see, for example, FREELANG)

Since he grows both the Corchorus and okra he is perfectly aware that the two leaves and plants are very distinct. His theory about the "okra leaf" name was that that might be referring to the sliminess/stickiness of the leaf:  not "leaf of the okra plant", but "slimy like okra" leaf.

(d) He also told me that a lot of his Filipino customers buy this green. He said the Filipino name is Saluyot. Interestingly enough, Filipino recipes online seem to recognize that it is jute. (see for example, Manong Ken’s Carinderia).

I hope that this clears up any lingering confusion. Thanks to my friend for her diligent research.

Random link from the archive: When caramel doesn't turn out right, make pudding

Saturday, October 09, 2010

Does the edible percentage of an avocado depend on its size?

Berkeley Bowl Marketplace in Berkeley, California is justly famous for its vast array of produce, and their avocado selection is no exception. They sometimes sell five different sizes of the fruit: pee wee, small, medium, large and extra large (almost all Hass variety). Naturally, they are at different prices and always by the piece, never by weight.

For a while I've been wondering two things about them: 1) does the fraction of edible material depend on the size of the avocado? and 2) what are the relative costs of the different sizes?  To answer these questions, I've been buying various sizes of Hass avocados from Berkeley Bowl and other places for the last few months and recording the weight of the whole fruit and the edible portion before eating. 

To date, I have weighed 19 avocados: 6 large, 6 medium, 3 small, 2 pee wee, and 2 extra large. The results of my measurements are in the chart below. The x-axis is the weight of the whole avocado in grams; the y-axis is the percent of the avocado that is edible, by weight. The different symbols represent the different sizes. The edible percentage is consistent across the span of weights, centered around 70%*, meaning that the amount of flesh you get from a Hass avocado is relatively independent of the total weight.  The 70% result is consistent with UC Riverside's Avocado Information site, which states that the seed, skin, and flesh percentages for Hass avocados are approximately 16%, 12% and 72%, respectively.

I don't know enough about avocados to say why the flesh percentage is so consistent across avocado weights. It might be the case that as avocados grow, the mass is added to the pit, skin and flesh at roughly the same rates. Or that when an avocado is ready to be harvested, the edible percentage happens to be around 70%. Whatever the case, what the graphs means for you is that choosing the heaviest avocado is likely to give you the most edible flesh, as opposed to a disproportionately large pit or thicker skin on a larger avocado.

I also recorded the cost of each avocado and calculated the cost per edible weight. Those results, however, are too messy and inconsistent to show here for a few reasons: prices varied during the experiment (it would have been better to buy, say, 10 of each size at one time), sometimes I bought organic avocados without recording that fact, some avocados were from the farmers market, and so forth. In any case, the results in the chart above can help you comparison shop.  Here's how:  given two avocados with different prices, weight each one, then calculate the ratios of the weights and the prices, with the larger avocado in the numerator. If the weight ratio is greater than the price ratio, the larger one is a better deal.  For example, a $0.99 "large" avocado weighing 260 grams vs. a $0.89 "medium" avocado weighing 190 grams.  The price ratio is 1.11, the weight ratio is 1.37, so the large avocado is the better deal (approximately $2.50 per pound of flesh for the large vs. $3.02 for the medium).

If you have any avocado data, want to send me some in the future, or know of already published sources, leave a comment or send me an email and I'll update the chart. What I need to know is the variety of avocado, the weight of the whole avocado, and the weight of avocado flesh (or the weight of the skin and pit). If you have a size grade (small, medium, large), that would also be useful.

As a final note for this post, here is an avocado mystery to ponder: Why are they sold by the piece and not by the pound? I personally have never seen avocados sold by the pound, and it doesn't make a lot of sense why not. Grocery stores already sell lots of different fruits and vegetables by weight. I asked the California Avocado Commission if there is a good reason for this, and they told me that it is completely up to the retailer to decide how to price their products.

* Except for the small avocados, which had a far lower edible percentage. Perhaps I wrote down the wrong weight in my notebook.

Photo of an avocado half from Andrea.Pacheco's flickr collection, subject to a Creative Commons License.

Random link from the archive: The Modern Burrito, a 'Fusion Food'

Technorati tag: Food

Friday, October 01, 2010

Cooking with Avocado Leaves: Oaxacan Black Beans

Photo from Kathy MacKey's Flickr collection (via CC)
In recent days, a generous friend served as a "forager" for the Mental Masala blog, obtaining some leaves from a Mexicola avocado tree, one of the varieties that has a distinct fragrance, as my previous post on avocado leaves explained. Since I had first seen the leaves used to flavor black beans — and had just purchased a new bag of Midnight Beans from Rancho Gordo's stand at the Ferry Plaza Farmers Market in San Francisco — I decided to debut the fresh leaves in a black bean dish, using a recipe in Rick Bayless's Mexican Kitchen as an inspiration.* 

I made a few changes to the Bayless's recipe, notably using Rancho Gordo's cooking method for the beans, frying the chorizo before adding it to the beans, not pureeing the beans at the end, and skipping the garnishes. The result was superb, with the anise-ish flavor of the avocado leaf complementing the rich sausage and earthy beans.

It seemed to me that the spices in the chorizo were a key factor in the dish's success, so if you don't eat pork, you might be able to craft a good approximation by incorporating some of the non-meat ingredients that go into chorizo. A recipe for red chorizo in Diana Kennedy's "From My Mexican Kitchen" is one example. In the recipe, ground pork is combined with a paste made from guajillo chiles, white vinegar, garlic, Mexican bay leaves (Litsea glaucescens, but the European Laurus nobilis make a suitable substitute), thyme, marjoram, Mexican oregano, cloves, allspice, and salt. To make the paste, the chiles are cleaned, deseeded, and soaked in warm water to soften. Once softened, they are drained and soaked in vinegar for an hour. Then the chiles and all of the other flavorings go into a blender, are pureed as smooth as possible and pressed through a sieve to remove seeds and other roughage (note that this is basically the procedure you'd use when making a mole or red chile enchilada sauce). To use in the beans, I would then cook the paste: heat oil in a sauce pan over medium-high heat, then add as much of the puree as I planned to use (a few tablespoons), stir well, and cook for a few minutes until it thickens slightly (again, like you'd do for a mole or enchilada sauce).

Ideally, my next project with avocado leaves would be a batch of tamales where I placed strips of avocado leaves between the tamale dough and the corn husk, but I probably won't have the energy for tamales in the near future, so I might instead try something simpler like the baked masa creation in Bayless's Mexican Kitchen (which is essentially a large batch of tamale batter stuffed with vegetables and baked in a loaf pan), placing a leaf or two between the batter and the pan so its magical flavors can infuse the masa and vegetables.

Recipe: Oaxacan Black Beans
Inspired by the Oaxacan black bean soup recipe in Rick Bayless's Mexican Kitchen

  • Cooking oil
  • 12 ounces dry black beans, rinsed, soaked (optional) and drained
  • Water
  • About 18 inch2 of avocado leaf (115 cm2), or 1 rib of fresh fennel, diced
  • 4 ounces chorizo sausage, casing removed, or chorizo chile and spice mixture
  • 1 small white onion, diced
  • Salt
(Unit conversion page)

If using a fresh avocado leaf, lightly toast it over gas burner on medium heat or on a hot griddle.

In a saucepan or Dutch oven, cook the onion in the oil over medium heat until tender. Add the beans, fresh water, and diced fennel or avocado leaf. Increase the heat, bring to a boil, and keep at a boil for five minutes. Turn down the heat, cover, and cook at a low simmer until the beans are tender (at this point, you could also transfer the mixture to a slow cooker or move the pot to a solar oven to complete the cooking).

In a small pan, cook the chorizo, breaking it up into small pieces, until it is lightly browned. Set aside.

Near the end of the bean cooking process, add the chorizo to the beans, stir, and add salt to taste. Remove the avocado leaf before serving.

* Leaves from the Hass variety, which is a hybrid Guatemalan-Mexican, do not have much flavor. Note also that while there have been reports that avocado leaves are toxic, this seems to apply only to leaves from Guatemalan and hybrid Guatemalan-Mexican varieties. Diana Kennedy, in her book "From My Mexican Kitchen," tries to clear up the confusion around the subject, noting that Mexican varieties were not found to be toxic, and in any case, "it seems unlikely that the small amounts used in cooking would cause any problems" (the full section is quoted at Gourmet Sleuth).  

Photo of Avocado leaves from Kathy MacKey's flickr collection, subject to a Creative Commons License.

Random link from the archive: Mexican Tlacoyos
Technorati tags: Mexico : Food