Speaker 1: Welcome to Stuff to Blow Your Mind, a production of iHeartRadio.
Speaker 2: Hey you welcome to Stuff to Blow your Mind. My
Speaker 2: name is Robert Lamb.
Speaker 3: And I am Joe McCormick, and today we're going to
Speaker 3: do another baby looked at Me style topic. My daughter
Speaker 3: is ten months old now, and after I came back
Speaker 3: on the show, after I came back from parental leave,
Speaker 3: I think I warned you all that there would probably
Speaker 3: be plenty of baby looked at Me style content in
Speaker 3: the coming years. And this is one that has really
Speaker 3: harnessed my brain. It starts with an observation that I'm
Speaker 3: sure anybody out there who has or has ever had
Speaker 3: young children will recognize. And it is what one might
Speaker 3: call anomalous adhesion syndrome, the sudden realization that an unusual
Speaker 3: surface in your house has become sticky and you don't
Speaker 3: know how it happened. I don't know. This is one
Speaker 3: of the anomalous phenomena that we need to resort to
Speaker 3: the proof of aliens confirmed column for. But I don't know.
Speaker 3: We'll see. And in my case, it starts with my
Speaker 3: child eating like a frozen fruit smoothie pop. Rob, I
Speaker 3: don't know if you ever made these in your house.
Speaker 3: But it's a nice little treat, you know. You like
Speaker 3: blend up some strawberries and bananas and stuff and freeze
Speaker 3: it in the freezer with a little handle.
Speaker 2: Yeah. Yeah, we have done this plenty of times. I
Speaker 2: think we've stopped using them though, but they're still in
Speaker 2: the freezer. I don't know when we filled the mold last,
Speaker 2: but they're still awaiting use.
Speaker 3: Well, so you give one of these to a baby.
Speaker 3: You know she loves it, but no surprise that her
Speaker 3: face gets sticky. You would expect that her hands get sticky,
Speaker 3: the floor around her gets sticky. But then later maybe
Speaker 3: you're like pulling a book off the shelf and you
Speaker 3: notice that the underside of the bookshelf is sticky. How
Speaker 3: did that happen? We could insert the X files music
Speaker 3: sting here, but I do have a hypothesis. At first
Speaker 3: it was a little more perplexing, but I think maybe
Speaker 3: it's that the adults in the house are acting as
Speaker 3: an intermediary or as a vector of stickiness from one
Speaker 3: surface to the other. So like during frantic moments of
Speaker 3: dealing with the baby, an adult is maybe getting stickiness
Speaker 3: from the baby on themselves, and then touching you know,
Speaker 3: the bookshelf, for the refrigerator door handle or whatever it is.
Speaker 2: Hmmm, well, that's pretty good. I mean, on one hand,
Speaker 2: you could just say sticky baby touches everything, and then
Speaker 2: therefore everything is sticky. I still think that's a solid hypothesis,
Speaker 2: this transference of sticky. This also holds what holds up well.
Speaker 2: I think another possibility is heightened stickiness thanks to baby
Speaker 2: results in heightened awareness of stickiness, and therefore you're just
Speaker 2: more inclined to notice stickiness now that there is an
Speaker 2: enhanced stickiness culprit in the household.
Speaker 3: You know, normally, I would say that kind of explanation
Speaker 3: makes a lot of sense, but I think for me,
Speaker 3: psychologically it's the exact opposite. I used to have much
Speaker 3: more awareness of the ickiness of stickiness, but now having
Speaker 3: a baby, I am I think I am somewhat desensitized
Speaker 3: to the to the icky of the sticky.
Speaker 2: Hmmm. Interesting. Yeah, I mean we still seem like, I
Speaker 2: still feel like we have enhanced stickiness in the household
Speaker 2: even at this point. And I think part of it
Speaker 2: too is just like you get a third body in
Speaker 2: the house, or you know, in larger family households, you know,
Speaker 2: multiple more bodies, that's more folks coming in and out
Speaker 2: of the kitchen, that's more folks handling food. Yeah, there's
Speaker 2: just kind of this exponential swell of stickiness. And then
Speaker 2: how do you handle it? Do you just become desensitized
Speaker 2: to it? Or do you try and keep up the
Speaker 2: battle against the sticky?
Speaker 3: Keeping up the battle is really a slog because another
Speaker 3: part of you know, a baby learning to appreciate solid
Speaker 3: foods is a lot of throwing foods on the floor,
Speaker 3: a lot of the floor.
Speaker 2: How did people cope with carpets, wall to wall carpets
Speaker 2: and children in the past. I don't know.
Speaker 3: Oh, I don't want to think about it. But anyway,
Speaker 3: so this got my brain cranking on the subject of stickiness,
Speaker 3: and I wanted to kick off a series today exploring
Speaker 3: the concept of stickiness and it's many wonderful, terrible and
Speaker 3: mysterious forms. So one place I was kind of foiled
Speaker 3: right at the beginning is I was like, Okay, is
Speaker 3: there just an answer to the question, sort of a
Speaker 3: chemistry or material science question, what makes a sticky thing sticky?
Speaker 3: I think it turns out this is one of those
Speaker 3: questions that seems like it should have a very simple answer,
Speaker 3: but in fact is rather difficult and complex, because while
Speaker 3: stickiness seems like one phenomenon to us, you know, we
Speaker 3: have a single word for it, it's actually a lot
Speaker 3: of different things. And I've been reading a book that
Speaker 3: addresses this a bit. It's a book called Sticky, The
Speaker 3: Secret Science of Surfaces, by Laurie Winkless from Bloomsbury twenty
Speaker 3: twenty three. So this is a new popular science book.
Speaker 3: It's not just about stickiness. It's also about slipperiness and
Speaker 3: generally about surface interactions, and the science thereof is by
Speaker 3: this author named Luri Winkless. And for everybody who says
Speaker 3: that you know, book jacket blurbs don't matter, I will
Speaker 3: say this is a case where I was swayed. I
Speaker 3: was convinced to go ahead and buy this one because
Speaker 3: it had a positive blurb from Mary Roach.
Speaker 2: Oh yeah, friend of the show Mary Roach. Always a
Speaker 2: ringing endorsement.
Speaker 3: But anyway, in the introduction to her book, Winkless reveals
Speaker 3: something that kind of surprised me, which is that despite
Speaker 3: the fact that stickiness and slipperiness are essential and probably
Speaker 3: universally recognized properties of substances in the world around us.
Speaker 3: You know they have crucial and perfectly well understood everyday meanings.
Speaker 3: To quote from her introduction, the words sticky and slippery
Speaker 3: are also not true materials properties in the way that
Speaker 3: say hardness and thermal conductivity are. They have no agreed
Speaker 3: upon scientific definitions and no specific metrics that can be
Speaker 3: used to quantify or compare them. Now, of course, stickiness
Speaker 3: and slipperiness do involve a number of well understood and
Speaker 3: mathematically well defined physics concepts like friction, viscosity, elasticity, and
Speaker 3: so forth. Apparently, they in themselves are kind of more
Speaker 3: vague and complex concepts, and they describe a number of
Speaker 3: different phenomena with different causes. So when you say that
Speaker 3: glue is sticky, and velcrow is sticky, and sugar syrup
Speaker 3: is sticky, you're using one word to describe a similar
Speaker 3: property these substances have. But the explanations can go in
Speaker 3: a variety of different directions. So this exploration of stickiness
Speaker 3: over the next few episodes will not be a single
Speaker 3: straight highway, but a bunch of diverging roads. Though, I
Speaker 3: think because we started with the example of food based
Speaker 3: substances getting on things and making them sticky. I think
Speaker 3: it might be good to stick to food for a bit.
Speaker 2: Let's stick to the food for a bit, yes, Because, yeah,
Speaker 2: stickiness is not always a byproduct of misplaced or spilled
Speaker 2: food treats. Sometimes it's a vital part of the culinary experience.
Speaker 2: And as we'll get into this, might not be as
Speaker 2: obvious to all listeners out there when we talk about, oh,
Speaker 2: don't you love it when the food is sticky? Don't
Speaker 2: you love it when the food is chewy? There's actually
Speaker 2: some rather stark differences that can be observed across different
Speaker 2: food cultures.
Speaker 3: Now, I'm sure when a lot of people think sticky foods,
Speaker 3: you immediately think sugar syrups and candy. But we're going
Speaker 3: to go in a slightly different direction here.
Speaker 2: That's right, because you have most chewy and sticky candies.
Speaker 2: I mean, yeah, that's the sweet dimension. But the example
Speaker 2: we're going to bring up here, it can be enjoyed sweet,
Speaker 2: it can be enjoyed savory. I'm talking about the sticky
Speaker 2: food par excellence. Sticky rice. So you may have a
Speaker 2: counted sticky rice in different forms. I mean, there's like
Speaker 2: bamboo sticky rice, there's Oh, there's mango sticky rice, which
Speaker 2: I think is absolutely amazing. You know, it's going to
Speaker 2: be different depending on you know, exactly what sort of
Speaker 2: mango you you have on there, but you can and
Speaker 2: sticky rice can be enjoyed with savory foods, it can
Speaker 2: be enjoyed with sweet foods. It's just absolutely tremendous.
Speaker 3: Now, when you say the phrase sticky rice, you could
Speaker 3: just be talking about rice and using sticky as an
Speaker 3: adjective to describe the rice. Because rice is, as we'll discuss,
Speaker 3: different varieties of rice are a varying levels of stickiness.
Speaker 3: But there is also a type of rice that is
Speaker 3: specifically sticky rice.
Speaker 2: That's right. Specifically, it's a Ariza sativa variant glutenosa, also
Speaker 2: known as glutenous rice. But don't let the name deceia view.
Speaker 2: It doesn't actually contain gluten. It is merely glutenous in
Speaker 2: that it is glue like or.
Speaker 3: Sticky, also sometimes called sweet rice. The last time I
Speaker 3: bought it at one of our local Asian markets, it
Speaker 3: was just in a bag that had sweet rice written
Speaker 3: on it.
Speaker 2: Yeah, and there are numerous cultivars of this particular type
Speaker 2: of rise and it's grown throughout Southeast and East Asia.
Speaker 2: This and the among the cultivars, you have mochigami, which
Speaker 2: is key to Japanese mochi, which is also one of
Speaker 2: life's great pleasures. Now where it gets interesting because ultimately
Speaker 2: the question arises where does the stickiness come in? What
Speaker 2: makes it stickier? So typical rice contains two starches, amelos
Speaker 2: and amelo pectin, but sticky rice lacks amelos and its
Speaker 2: absence leads to this sticky quality that we have. This
Speaker 2: is due to a mutation in its waxy gene. DNA
Speaker 2: evidence suggests that it emerged a single time somewhere in
Speaker 2: Southeast Asia, and the resulting stickiness was seemingly light, preserved, encouraged.
Speaker 2: You know that we see this story time and time
Speaker 2: again throughout the history of domesticated and cultivated foods, where
Speaker 2: something changes in the particular plant and we realize, oh,
Speaker 2: this is even better than before.
Speaker 3: Yeah, I can see that. In another way, I kind
Speaker 3: of think about a glutinous rice as blasting off of
Speaker 3: one end of the rice experience spectrum. So, just from
Speaker 3: personal experience in the kitchen, I'm familiar with the properties
Speaker 3: of different kinds of cooked rice, and there is a
Speaker 3: general pattern that longer grain rice varieties tend to be
Speaker 3: firmer and less sticky, so they stick to each other less.
Speaker 3: So you think of the example of basmadi rice used
Speaker 3: in a lot of Indian cuisine and other long grain
Speaker 3: rice is they tend to have grains that separate from
Speaker 3: one another more easily and remain firmer after cooking. So
Speaker 3: these rices kind of flake when you toss them with
Speaker 3: a fork after cooking. Rob you know that experience.
Speaker 2: Yeah, yeah, And of course this becomes vital too if
Speaker 2: you're going to be potentially eating with chopsticks. You know
Speaker 2: what kind of rises are going to clump together in
Speaker 2: which ones are going.
Speaker 3: To fall apart. Yes, these would be more difficult to
Speaker 3: eat with chopsticks, though you know, with enough practice you
Speaker 3: need almost anything with chopsticks. Yeah, yeah, especially if you
Speaker 3: got some kind of saucy, wet thing to kind of
Speaker 3: stick it together. But yes, the grains that separate from
Speaker 3: one another more easily like this, the long grain rices
Speaker 3: are more difficult. Meanwhile, shorter grain rices tend to be
Speaker 3: softer in texture and stickier. They stick to each other
Speaker 3: and stick to other things more easily. So you can
Speaker 3: think of short grain rices like you know ar boreo
Speaker 3: rice which is commonly used in risotto, or short grain
Speaker 3: sushi rice which is tender and sticks together nicely to
Speaker 3: you know, make into sushi rolls or other multiple forms.
Speaker 3: And this correlates to what you mentioned, Rob that changing
Speaker 3: ratio of ammelos to amelopectin, longer grain rices tend to
Speaker 3: have more ammelos and shorter grain rices tend to have less.
Speaker 3: Glutenous rice goes even beyond the normal short grain rice.
Speaker 3: It has especially low ammelose content and high a melopectin,
Speaker 3: which causes the rice to, once it's cooked, clump together
Speaker 3: for molding purposes in cooking, and retain a really sticky
Speaker 3: adhesion between grains while eating. It's also worth noting that
Speaker 3: sticky rice is used to create a number of secondary
Speaker 3: food products like Shoushing wine, which is used in a
Speaker 3: lot of Chinese cooking, is usually made by fermenting a
Speaker 3: mash containing glutinous rice. In particular, Japanese sake is an
Speaker 3: alcoholic beverage that I think is also often made with
Speaker 3: fermented sticky rice. But I was getting curious about what
Speaker 3: actually makes the difference. Why do these different ratios of
Speaker 3: amelos and amlopectin change the stickiness and the texture of rice.
Speaker 3: Like what's happening at the sort of at the molecular level.
Speaker 3: So I was looking all over for a good explanation
Speaker 3: that I could actually understand of what exactly is happening here,
Speaker 3: and eventually I found a great article about this by
Speaker 3: an author named Guy Crosby, who writes about food science
Speaker 3: for America's Test Kitchen and teaches at the Department of
Speaker 3: Nutrition at Harvard's chan School of Public Health. And so
Speaker 3: here's the way Crosby explained it. You got to start
Speaker 3: off by understanding what starch is. Starch is a carbohydrate
Speaker 3: that is found in lots of foods, and it is
Speaker 3: the natural way that plants store energy, store food energy
Speaker 3: that they make via the process of photosynthesis. And so
Speaker 3: this is kind of an interesting connection to like, when
Speaker 3: you're thinking about the food you eat, think all the
Speaker 3: way back to like how that energy entered the planet
Speaker 3: Earth in the form of sunlight and turned into the
Speaker 3: food on your plate. So, of course plants make their
Speaker 3: own food by way of photosynthesis, which means they are
Speaker 3: forcing a chemical reaction between carbon dioxide in the air
Speaker 3: and water, and that chemical reaction is powered by the
Speaker 3: energy from sunlight, and it produces is glucose or sugar
Speaker 3: carbohydrates as a product that's the food for the plant,
Speaker 3: and then oxygen as a byproduct. Plants then convert the
Speaker 3: sugar they produce through photosynthesis into starch, which is a polymer.
Speaker 3: It's this huge macromolecule that is composed of smaller individual
Speaker 3: molecules all linked together in a big chain. And starch
Speaker 3: is a natural form of high density energy storage. It's
Speaker 3: a way to squeeze a ton of chemical energy into
Speaker 3: a very compact space. All of this sugar is packed
Speaker 3: into one tight, gigantic molecular structure. This starch structure is
Speaker 3: known as a granule. So sometimes you can actually look
Speaker 3: up like microscopic imagery of starch granules and they have
Speaker 3: a interesting little little like if you look at a
Speaker 3: cross section of one. Sometimes they'll have these little rings,
Speaker 3: kind of like the rings of a tree. That's interesting.
Speaker 3: And when plants make these starch granules, they are storing
Speaker 3: the glucose in starch in two distinct molecular forms. One
Speaker 3: is amylose and one is Amylopectin. These two starches we
Speaker 3: mentioned earlier ammelos is a linear molecule which is smaller
Speaker 3: in size, and amylopectin is a larger molecule with a
Speaker 3: kind of branching out structure, And these amelos and amylopectin
Speaker 3: pectin molecules are organized into these tight structures called granules.
Speaker 3: And then inside the granules there are layers with a
Speaker 3: different makeup. So there are these like tightly crystallized, highly
Speaker 3: structured organized layers, and then there are more amorphous, non
Speaker 3: crystallized layers with more random arrangements of amylose molecules and
Speaker 3: amylopectin any kind of non regular pattern. So why does
Speaker 3: that matter, Well, you got to look at what happens
Speaker 3: when starch granules get cooked in hot water. When the
Speaker 3: starch granules are in water above a certain temperature, that
Speaker 3: water starts to pin trait the starch granule, causing it
Speaker 3: to swell. So you can imagine water molecules like soaking
Speaker 3: into something I don't know, like a couch cushion or
Speaker 3: something and making it like swell up, and that makes
Speaker 3: it swell up kind of like a balloon in a way.
Speaker 3: And as these starch granules in hot water get hotter
Speaker 3: and hotter, they eventually reach a breaking point their maximum
Speaker 3: volume and viscosity, as Crosby says, and this is called
Speaker 3: their gelatinization temperature. And eventually what happens is they burst.
Speaker 3: They just like leak pieces of starch molecules all out
Speaker 3: into the water around them. Exactly what temperature this is
Speaker 3: depends on the type of starch e g. What plant
Speaker 3: it comes from. And a key factor is the ratio
Speaker 3: of amylose to amelopectin in each starch granule. So the
Speaker 3: more amylose there is in the starch, the more the
Speaker 3: swelling of the granule in the presence of hot water
Speaker 3: is delayed. So you can kind of think of amylose
Speaker 3: as an armor against gelatinization. The more amlos, the higher
Speaker 3: the gelatinization temperature, and the more the granule fights off
Speaker 3: the gelatinization process. And then Crosby uses the example of
Speaker 3: rice to show this process. He writes, quote, long grain
Speaker 3: rice contains about twenty two to twenty eight percent ammelos
Speaker 3: by weight, Medium grains contain about sixteen to eighteen percent
Speaker 3: by weight, while short grain contains less than fifteen percent
Speaker 3: to almost no ammelos. Varieties of long grain rice have
Speaker 3: a gelatinization temperature above one hundred and fifty eight degrees
Speaker 3: fahrenheit or seventy degrees celsius, while waxy short grain rice
Speaker 3: gelatinizes at about one hundred and forty four degrees fahrenheit
Speaker 3: or sixty two degrees celsius. So the temperature in the
Speaker 3: short grain rice is the temperature for gelatinization is lower,
Speaker 3: meaning it happens more easily. So the granules of starch
Speaker 3: in short grain rice with lower ammelose content reach their
Speaker 3: gelatinization point and burst at a lower temperature. And when
Speaker 3: the starch granules burst, they flood the surrounding one with
Speaker 3: disorganized small chunks of amylos and amylopectant of just little
Speaker 3: bits of starch, Crosby writes quote, creating an infinite network
Speaker 3: of entwined molecules that trap water and thicken to a
Speaker 3: gel on cooling. So this mesh of loose, uncrystallized starch
Speaker 3: molecules thickens the water and causes the rice grains to
Speaker 3: stick together. And you can actually observe a similar principle
Speaker 3: when you use starch to thicken other foods thicken like
Speaker 3: a soup or a sauce. If you've ever used a
Speaker 3: roue based on wheat flour or a corn starch slurry.
Speaker 3: It's the same principle. Corn starch flour, potato starch and
Speaker 3: so forth all undergo the same gelatinization process, though at
Speaker 3: different temperatures and rates. So the starch granules will swell
Speaker 3: up and eventually burst in hot water, and this has
Speaker 3: the effect of increasing the viscosity, meaning the thickness and
Speaker 3: the stickiness of the water based or sauce. So that
Speaker 3: is how the lower ratio of ammelos to amelopectin makes
Speaker 3: the cooked rice sticky.
Speaker 2: Ah, fascinating, fascinating. So all that's going on at the
Speaker 2: at the micro level and at the macro level, you're
Speaker 2: just enjoying some some sticky rice. Maybe a little sweet,
Speaker 2: maybe you're a little savory. It kind of depends on
Speaker 2: the particular dish. I don't think we can properly prepare
Speaker 2: you for the stickiness just in this audio podcast is
Speaker 2: something you need to fully to fully appreciate. You need
Speaker 2: to try it for yourself. But it's it's generally like
Speaker 2: when I've had it, oftentimes, not only could you eat
Speaker 2: it with a with a pair of chopsticks, you could
Speaker 2: eat it with like one of those little like wooden
Speaker 2: planks that comes They used to come on the top
Speaker 2: of ice creams. You could eat it with a popsicle stick,
Speaker 2: you know.
Speaker 3: Mm hmm. Sticky rice is often used for a like
Speaker 3: molding purposes, so you can wrap it round foods, or
Speaker 3: you can just use it as sort of like forming
Speaker 3: little little bits of it or paddles of it in
Speaker 3: your hand and scoop up foods with it. But there's
Speaker 3: another thing about the texture of sticky rice, which is
Speaker 3: that I think it's because of this gelatinization that it
Speaker 3: has a similar thing going on that like risotto has,
Speaker 3: which is a creaminess.
Speaker 2: Yeah, yeah, I can definitely take on this creamy, gooey
Speaker 2: kind of texture, has this incredible mouth feel. It can
Speaker 2: make for an overpoweringly good dessert, but again also works
Speaker 2: very well in savory and plays a very important role
Speaker 2: in various cuisines in various traditions, especially I've read in
Speaker 2: the culinary traditions of Laos in Laotian cooking. As pointed
Speaker 2: out by Mike Ives in a Taste of Sticky Rice,
Speaker 2: Laos's national dish, it can be steamed twice during the
Speaker 2: course of the day, beginning first thing in the morning.
Speaker 2: So like traditionally sticky rice is something you make right away,
Speaker 2: like this is how you start off your day. A
Speaker 2: third steaming ives rights is said to just make it
Speaker 2: too chewy to eat at that point, but the author
Speaker 2: points out that quote a hunk of sticky rice is
Speaker 2: a delicious bread like dipping implement. So I looked around
Speaker 2: at some other sources on this, and yet traditionally in
Speaker 2: Laotian cuisine, one rolls it up with one's fingers and
Speaker 2: then dips it into sauces, which is, you know, it
Speaker 2: is even a little bit different than other uses of
Speaker 2: sticky rice. You might be more familiar with.
Speaker 3: One of the many great world food traditions of make
Speaker 3: your own utensils and then eat the utensil.
Speaker 2: Yeah, yeah, I've been to I think I think I've
Speaker 2: only been to one Laotian restaurant a couple of times,
Speaker 2: and I don't remember enjoying the sticky rice like this,
Speaker 2: And now I want to. I really want to seek
Speaker 2: it out and have this experience. Anyway, the importance of
Speaker 2: sticky rice and laos goes well beyond just you know,
Speaker 2: how you start your day. It factors into Laotian Buddhist
Speaker 2: rights and traditions will come back a little to a
Speaker 2: little bit to this in just a few minutes here.
Speaker 2: But it also was apparently long sought after by monks
Speaker 2: because quote as ice rites quote, it takes longer to
Speaker 2: digest than white rice does. It states hunger for longer periods.
Speaker 2: So I thought that that was an interesting tidbit. Is
Speaker 2: another reason to have it first thing in the morning. Now,
Speaker 2: whether that actually how much of that is the actual
Speaker 2: science of the digestion of sticky rice versus other varieties
Speaker 2: of rice, I don't know, but and I can't help
Speaker 2: but wonder too if there's some version of like food
Speaker 2: sticking to your ribs, if there's some sort of like
Speaker 2: idea of that in Laotian traditions as well. I'm not
Speaker 2: sure linguistic stickiness and so forth. Anyway, getting into the
Speaker 2: just sort of the history of rice and the possible
Speaker 2: like history of like when did sticky rice emerge? There
Speaker 2: are various dates you'll come across for some of this.
Speaker 2: There's so a lot of work has gone into like, well,
Speaker 2: you know, when do we see this particular rice variety
Speaker 2: pop up? And what does genetic information tell us the
Speaker 2: domesticated species or Za sativa or Asian rice evolved starting
Speaker 2: approximately nine thousand years ago. I've read this according to
Speaker 2: Filipino American biologist Michael Pruganin in twenty ten. I've also
Speaker 2: seen it written that Asian Neolithic farmers are thought to
Speaker 2: have cultivated rice more than eleven thousand years ago. There
Speaker 2: may be some wiggle room here again when you get
Speaker 2: down to exact dates and ideas about when particular plant
Speaker 2: varieties emerged or domesticated, et cetera. Now, in the study
Speaker 2: of rice genetics and in particular sticky rice genetics, Pruganin
Speaker 2: has several different articles credited to him, and working with
Speaker 2: Kenneth Olsen for North Carolina State University back in two
Speaker 2: thousand and two, he set out to explore the origin
Speaker 2: of sticky rice because ultimately no one knew exactly where
Speaker 2: it came from. You know, we could look to its
Speaker 2: importance in these various culinary traditions, but you know, we
Speaker 2: didn't have like hard genetic data. Apparently, they pointed out
Speaker 2: that on one hand, you had a Laotian Buddhist claim
Speaker 2: that it emerged there eleven thousand years ago. Meanwhile, Chinese
Speaker 2: folklore suggested that it existed two thousand years ago and
Speaker 2: so forth. Now I was intrigued by this, you know,
Speaker 2: mention of the folklore and mythology and so forth. Here
Speaker 2: I was able to find more on Laotian rice myths,
Speaker 2: particularly in the book that he cites Rice Legends in
Speaker 2: Mainland Southeast Asia by Baron Jay Tierweil. And basically you
Speaker 2: can find longer versions of this online. But the basically
Speaker 2: you have this Laotian Buddhist origin story for sticky rice,
Speaker 2: and it concerns the rice goddess nang Kosap, who is
Speaker 2: essentially not only a goddess of rice, but is Rice incarnate,
Speaker 2: who like her body is rice, her identity is rice.
Speaker 2: And you know, we see this reflected in the same
Speaker 2: idea in other traditions, other mythologies, where you have some
Speaker 2: sort of vital food crop that is personified in a
Speaker 2: given deity.
Speaker 3: Oh well, yeah, I mean I think if the goddess
Speaker 3: series C E. R e s whose name you see
Speaker 3: the connection to cereal, the goddess of grain.
Speaker 2: Yeah, yeah, you see similarities too to the importance of
Speaker 2: maize in Mesoamerican traditions. Anyway, the interesting thing about Nan
Speaker 2: coostop here. The thing I found really interesting is that
Speaker 2: she has this relationship with humanity, and when the actions
Speaker 2: of humans upset her or offend her, she'll recede from
Speaker 2: our world. And of course, when this happens, it results
Speaker 2: in famine. So there are at least two vital periods
Speaker 2: of divine famine in Laotian Buddhist traditions, the second being
Speaker 2: when an evil king hoards all the rice and then
Speaker 2: the rice stops growing elsewhere. And according to the story,
Speaker 2: after three hundred and twenty years of this particular famine,
Speaker 2: a wise hermit finally offers to fixed matters, and he
Speaker 2: does so by sacrificing the goddess pulls her into pieces,
Speaker 2: and each of these pieces would become one of the
Speaker 2: four main varieties of rice that are of special value
Speaker 2: in Laotian cuisine, black rice, white rice, anim rice, and
Speaker 2: sticky rice. And it said that she does not resist this,
Speaker 2: she just holds her breath and dies as she's divided
Speaker 2: into these pieces. But on top of this, there's this
Speaker 2: added level of prophecy. When Maitreya, the Bodhisattva of the future,
Speaker 2: is born on this world, quote all rice varieties will
Speaker 2: reunify to become the original Rice.
Speaker 3: Whoa Well, on one hand, I was going to say
Speaker 3: that is an apocalyptic prophecy of the future that I
Speaker 3: can get behind. But then the more I think about it,
Speaker 3: I'm like, wait, but I like all the different varieties
Speaker 3: of Rice.
Speaker 2: But you haven't tried the original Rice.
Speaker 3: Right, Well, that's true. Maybe maybe it would be as
Speaker 3: good as all of them put together.
Speaker 2: There there are you know, I don't didn't have time
Speaker 2: to get into it so much for this episode, but
Speaker 2: this particular source, this book Rice Legends in mainland Southeast Asia.
Speaker 2: It you know, it also gets into these various other
Speaker 2: ideas and myths concerning Rice about how Rice used to
Speaker 2: be bigger. I think in some cases, like they're talking
Speaker 2: about back when rice was the size of like coconuts
Speaker 2: or something, you know, so.
Speaker 3: You know their grain.
Speaker 2: Wow, yeah, I guess so. And then there are various
Speaker 2: stories about, well, it's not as big as it used
Speaker 2: to be because it was cursed by a widow. And
Speaker 2: in some cases, like Rice in general is lost and
Speaker 2: then found again. So it looks like there's a there's
Speaker 2: a lot of fascinating twist and turns in the sort
Speaker 2: of mythic history of rice, and you wonder about like
Speaker 2: the various disasters that that it speaks to you times
Speaker 2: when rice crops were lost, or people moved from one
Speaker 2: region to another and had to sort of refined or
Speaker 2: adapt their method of growing rice and so forth.
Speaker 3: That's an interesting ideology.
Speaker 2: So anyway back to the actual origins of rice as
Speaker 2: far as DNA evidence reveals. So back in two thousand
Speaker 2: and one, Programon's team found that sticky rice's genetic mutation
Speaker 2: maps to a single mutation on the genetic tree, suggesting
Speaker 2: that it occurred only once. They looked at the geographic
Speaker 2: data for the rice DNA sequences and found that Southeast
Speaker 2: Asia was in fact the likely location of its emergence.
Speaker 2: So the picture we see of rice cultivation suddenly here
Speaker 2: is rice cultivation suddenly generates something new and exciting, and
Speaker 2: it's something where people latch onto it. There they're like, Okay,
Speaker 2: well this is different. I think we can do different
Speaker 2: things with this. And in this particular case, we're talking
Speaker 2: about chewiness. We're also talking about you know, stickiness, but
Speaker 2: I guess once it's in your mouth, it's not about
Speaker 2: being sticky. It's about being chewy. And also in the
Speaker 2: Laotian example about like rolling up the rice and dipping it,
Speaker 2: it also shows that like the stickier the rice and
Speaker 2: or chewier the rice, it opens up new ways of
Speaker 2: using it physically in your food, Like it's no longer
Speaker 2: has to be in the bowl. Well, now we can
Speaker 2: dip it in the bowl. Like you say, it becomes
Speaker 2: the utensil.
Speaker 3: Yeah, you can almost treat it more like like a
Speaker 3: dough or something, except it's a dough that like is
Speaker 3: already cooked and ready to eat. It's as moldible as
Speaker 3: a dough, but it's already ready to go. Yeah.
Speaker 2: And Japanese moch is just another example of this as well,
Speaker 2: Like that chewiness, the things you can do with it.
Speaker 2: So why do we like chewy foods? Why would withou
Speaker 2: this chewy aspect of this rice, The sticky aspect of
Speaker 2: this rice, you know, cause it to be picked up
Speaker 2: and embraced and then cultivated. Well, I found an interesting
Speaker 2: article about this that touches on some of the you
Speaker 2: know the differences between particularly between Eastern and Western culinary traditions.
Speaker 2: And this was a bone Appetite article titled everyone Loves
Speaker 2: Crispy and crunchy, But what about chewy? This is from
Speaker 2: twenty nineteen by author Elise in Nominee. My apologies if
Speaker 2: I've got the pronunciation on that last name wrong, but
Speaker 2: it's a wonderful article, and she points out that in
Speaker 2: the modern West, chewy may sometimes be associated with something
Speaker 2: that's underdone or overdone, you know, the results of poor cooking.
Speaker 2: You know, why is this steak so chewy? Or why
Speaker 2: is this other you know, I can't think of any
Speaker 2: other specific examples off the top of my head, but
Speaker 2: this is chewy? Please take it back?
Speaker 3: Yeah, I mean traditionally, like the way meats are priced
Speaker 3: in American supermarkets is there's a direct correlation with tender,
Speaker 3: Like the dollar amount per pound of meat directly correlates
Speaker 3: to how naturally tender is the meat. And so your quote,
Speaker 3: cheap cuts of meat are the ones that are going
Speaker 3: to be really tough unless you subject them to long,
Speaker 3: slow cooking processes.
Speaker 2: Yeah. But according to the author, here in Eastern Cuisines,
Speaker 2: there's this richer history of chewy foods, and one of
Speaker 2: her key arguments for the enjoyment of chewy foods is
Speaker 2: that it kind of prolongs the tasting experience, which is
Speaker 2: interesting because on a basic level, you're working over the
Speaker 2: texture and flavor in your mouth much longer. She argues
Speaker 2: that across East and Southeast Asian cuisines, chewiness quote isn't
Speaker 2: just a common texture, but a powerful tool deployed to
Speaker 2: make food taste better. So this idea of stickiness or
Speaker 2: chewiness is kind of a flavor enhancer of sorts.
Speaker 3: That's interesting.
Speaker 2: Something this reminds me of the discussion is also even
Speaker 2: in case you encounter these I think they're called talk
Speaker 2: rice cakes. They are these like chewy little rice cakes
Speaker 2: that you get in various Korean stews. Have you had
Speaker 2: these before, Joe.
Speaker 3: Yes, I think so. They're made with well, I don't
Speaker 3: know exactly how they're made. I assume they're made with
Speaker 3: either rice flour or something or like mashed up grains
Speaker 3: of rice, but they are. They form like a solid
Speaker 3: white puck sort of, and yeah, they've got a really
Speaker 3: nice bouncy, chewy, springy texture, kind of like rice noodles,
Speaker 3: but very thick.
Speaker 2: Yeah, and I can see where like having those nice
Speaker 2: chewy bits in this flavorful stew, you know, it kind
Speaker 2: of forces you to to sort of experience the flavors
Speaker 2: in that stew in a different way. So yeah, this
Speaker 2: really made me rethink a lot of the ways that
Speaker 2: I'm encountering chewy bits and various foods. Now, the usefulness
Speaker 2: of stickiness and sticky rice also goes well beyond culinary uses.
Speaker 2: It also factors into sticky rice mortar, an ancient, apparently
Speaker 2: Chinese development that dates back a good fifteen hundred years.
Speaker 2: We'll get into some of the discussions about how far
Speaker 2: back this might go, but basically it's a mixture of
Speaker 2: slacked lime with sticky rice soup. I was reading about
Speaker 2: this in in a paper from twenty nineteen by Lee
Speaker 2: and Zang published in the Journal of Archaeological Method and Theory.
Speaker 2: This was this is an interesting when the authors looked
Speaker 2: at three hundred and seventy eight ancient mortar samples from
Speaker 2: throughout China across one hundred and fifty nine ancient buildings
Speaker 2: in archaeological relics. Two hundred and nineteen mortar samples from
Speaker 2: ninety six buildings contained organic components. One hundred and twelve
Speaker 2: samples contained starch, eighty seven oil, fifty nine protein, fourteen sugar,
Speaker 2: and five blood. Who now on the blood point. I'm
Speaker 2: not going to go too deep into this here, but
Speaker 2: I think there might be a temptation for us to
Speaker 2: instantly think about, you know, some of like sacrificial aspect,
Speaker 2: and you do see sacrificial rites associated with various building
Speaker 2: traditions throughout the world, you know, foundation sacrifices and so forth.
Speaker 2: But also you see a lot of these sorts of
Speaker 2: organic ingredients used in various things like dyes and paints,
Speaker 2: et cetera. So you know, one thinks too like the
Speaker 2: use of organic bits from egg and paints that were
Speaker 2: used to create various works of art. But the authors
Speaker 2: here point out that the of course, the line portion
Speaker 2: of mortar goes way back to somewhere between seven and
Speaker 2: twelve thousand BCE and Palestine and Turkey. Various inorganic additives
Speaker 2: were used throughout the history of mortar, such as volcanic ash,
Speaker 2: which was often added by the Greeks, but organic additives
Speaker 2: were used as well, including just about anything you could
Speaker 2: think of animal here, plant seeds, plant fibers, egg wides,
Speaker 2: egg yolk, animal glue, fish oil, whale oil, all sorts
Speaker 2: of stuff. Now, Chinese use of lime mortar goes back
Speaker 2: a good five thousand years, they say, but there's evidence
Speaker 2: of different additives being used at different points in different places.
Speaker 2: Sticky rice in particular pops up in tombs and pagodas
Speaker 2: dated to the Southern and Northern dynasties. This would have
Speaker 2: been between the years four twenty and five to eighty nine.
Speaker 2: The starch content of their samples are directly linked to
Speaker 2: the extremely common practice of using sticky rice mortar. Some
Speaker 2: of the samples included city walls. They also point out
Speaker 2: that while the Southern and Northern dynasties are generally considered
Speaker 2: the earliest possible time for sticky rice mortar to have
Speaker 2: been used in China, they claim to have found one
Speaker 2: starch sample from the Eastern Han dynasty that would have
Speaker 2: been between the years twenty five and two twenty, which,
Speaker 2: if accurate, would push that estimate back.
Speaker 3: All right, So why would you be adding food substances
Speaker 3: like sticky rice or any of these other things to
Speaker 3: the mortar you were using to build buildings.
Speaker 2: I mean, basically it comes down to, like trying to
Speaker 2: make a better mortar. Things you can add to increase
Speaker 2: the bond strength in the mortar, And that seems to
Speaker 2: be the case here. A twenty ten paper published in
Speaker 2: the American Chemical Society monthly journal Accounts of Chemical Research
Speaker 2: by Yang at All looked into the legendary strength of
Speaker 2: sticky rice mortar, because all these stories about how strong
Speaker 2: it was and how strong it still is, how well
Speaker 2: it holds up, they're like anecdotes about like modern bulldozers
Speaker 2: not being able to knock it down. And they found that,
Speaker 2: you know, first of all, it's the emelopectin that's the
Speaker 2: key ingredient in the sticky rice soup that helps strengthen
Speaker 2: the mortar. It acts as an inhibitor, controlling the growth
Speaker 2: of the calcium carbonate crystals, producing a compact microstructure. So
Speaker 2: this results in improved mechanical strength, makes it less permeable
Speaker 2: to water and more resistant to weather related stresses. They
Speaker 2: also point out that it's it's key to recreate ate
Speaker 2: this sort of mortar for restoration work on ancient buildings.
Speaker 2: I hadn't thought about this, but they make the case
Speaker 2: that because modern mortar, of course, it's come a long ways,
Speaker 2: and it can actually prove too strong and it can
Speaker 2: damage older, softer bricks, which, of course I'm not sure
Speaker 2: we're necessarily talking about situations where we're using mud bricks.
Speaker 2: But it makes me think back to our discussion of
Speaker 2: mud bricks on the show previously.
Speaker 3: Oh interesting, but in this case, if they found it's
Speaker 3: the amelopectin which gives the mortar the desirable quality. Here,
Speaker 3: So this is why sticky rice in particular would be
Speaker 3: useful because it's got the highest ratio of amelopectin the
Speaker 3: lowest ratio of ammelose.
Speaker 2: Yes and therefore apparently resulted in just a superior mortar
Speaker 2: for a very long time. And you know that again
Speaker 2: frequently used in things like like walls and tombs and
Speaker 2: so forth, city walls in particular, so defensive structures.
Speaker 3: The sticky rice is not just delicious, it's not just
Speaker 3: and muldable. It keeps us safe.
Speaker 2: Yeah, So it's a it's fascinating to try and sort
Speaker 2: of imagine these developments, you know, like how much of
Speaker 2: it is just let's try anything. Let's let's just experiment
Speaker 2: with adding different organic and inorganic ingredients to mortar to
Speaker 2: see what we can get, but also that kind of
Speaker 2: experiential level of like, well, look at what happens with
Speaker 2: this particular type of rice. We know how sticky it
Speaker 2: can get. We know how chewy it can get. Let's
Speaker 2: experiment with just with adding this to the mortar. It
Speaker 2: makes sense and then it pays off gorgeous. Yeah, because
Speaker 2: that what you want your buildings to stick together? Right?
Speaker 3: All right, Well, maybe that is going to do it
Speaker 3: for part one of the series, but we will be
Speaker 3: back to talk about stickiness and sticky things more in
Speaker 3: part two.
Speaker 2: That's right. We already have some avenues mapped out for
Speaker 2: us here, but it's possible there's something we haven't thought of.
Speaker 2: So if there's a particular sticky topic or sticky stickiness
Speaker 2: related topic'd like for us discuss to discuss on this series,
Speaker 2: just write in. We'd love to hear from you. A
Speaker 2: reminder that Stuff to Blow Your Mind is primarily a
Speaker 2: science podcast with regular core episodes on Tuesdays and Thursdays,
Speaker 2: but on Mondays we do a little listener mail, on
Speaker 2: Wednesdays we do a short form artifact or monster fact,
Speaker 2: and on Fridays we set aside most serious concerns to
Speaker 2: just talk about a weird film on Weird House Cinema.
Speaker 3: Huge thanks as always to our excellent audio producer JJ Posway.
Speaker 3: If you would like to get in touch with us
Speaker 3: with feedback on this episode or any other, to suggest
Speaker 3: topic for the future, or just to say hello. You
Speaker 3: can email us at contact Stuff to Blow Your Mind
Speaker 3: dot com.
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