Matcha Science with Dr. Yizhou Ma
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Ryan And Sam (00:00)
Hello and welcome to the Specialty Matcha podcast. My name is Ryan, this is my co -host Zongjun Hello, hello. And we're the co -founders of Sanko Matcha products. Yeah, so we launched this podcast to discuss our learning journey in Matcha, share startup stories and interview experts. And today we are happy to have our beloved friend, Dr. Yizhou Ma, joining our podcast. Hi, Yizhou.
Yizhou (Ben) Ma (00:21)
Hi Ryan, hi Zongjun. It's very nice to be here.
Ryan And Sam (00:24)
I was just about to call you Ben. I just about to call you Ben, then I stopped. Well, dear audience, you us address someone as Ben, it means Yizhou we were all actually former colleagues at the last company. I think you joined right after you got your masters in dairy science.
Yizhou (Ben) Ma (00:29)
No, no, no, please, go ahead, call me back.
Ryan And Sam (00:46)
And then during COVID, you went to go pursue a PhD in Netherlands. So now we can call you Dr. Yizhou Ma, which also is a new name for us.
Yizhou (Ben) Ma (00:55)
Yes.
Yes.
Yeah, I'm very happy to be here and talk about matcha today.
Ryan And Sam (01:03)
Yeah, so Yizhou, can you maybe share a little bit background information about what you do, what's your academic background, what you're working on, and what's your impression about Matcha as a consumer?
Yizhou (Ben) Ma (01:14)
Sure, Well, like Ryan said, right? So I started a PhD degree, working on my PhD degree during COVID. I defended my PhD thesis and got a doctoral title, although, you know, as a person who's a bit of an anti -achiever.
So I don't quite refer myself with the doctor title. But ever since I got my doctor degree, I started a new position as an assistant professor of food technology at Wageningen University in the Netherlands. And I'm housed into research groups. One is food process engineering, and one is food quality and design.
So that speaks a bit of what my day job would be. So doing a lot of work with turning ingredients into food and also spending time analyzing the quality of the food and how it interacts with consumers. Yeah, about matcha itself, I would say I'm a very occasional consumer of just matcha tea by itself. I would rarely...
really consume any of the matcha flavored snacks or other food products, simply because the matcha flavor standards are little low for the typical consumer product that I would be able to get. Yeah, and the very occasional drinking of matcha is also kind of tied to the reason that I was thinking about this. I have a daily beverage pie chart.
Ryan And Sam (02:21)
Hahaha
Yizhou (Ben) Ma (02:36)
right, so, and it's filled with other type of beverages of choice. So sometimes matcha makes into a thin slice of my beverage of choice, but that's normally limited to not having a lot of good access to nice matcha. And also I have to confess that I don't have a very large
Ryan And Sam (02:44)
Yeah.
Yizhou (Ben) Ma (02:56)
facility or gears of brewing good matcha. So that's also part of the reason that I normally just get it from cafes instead of brewing it myself.
Ryan And Sam (03:07)
Interesting. What are some of the fatter slice of the pie in your beverage chart Yizhou?
Yizhou (Ben) Ma (03:14)
yeah, yeah, yeah. Well, that certainly goes still to a lot of coffee. Recently, also a growing slice of loose leaf tea, let's say, in general. Yeah, and then certainly various alcoholic type of beverages
you know, good old water. We can't forget about water.
Ryan And Sam (03:31)
Very important.
Yizhou (Ben) Ma (03:32)
Yeah.
Ryan And Sam (03:32)
I've noticed too in Europe that the matcha quality is maybe the lowest in the world. In the States, it's also kind of a gamble. But in Europe, even if you go to matcha specialty places, like in Paris for example, really is... disgusting is probably the right word. And they're charging 3, 4, 5, 6 euros.
Yizhou (Ben) Ma (03:55)
Thank
Ryan And Sam (03:57)
Whoa, that's crazy. It's expensive and it's Whoa.
Yizhou (Ben) Ma (04:01)
yeah, I would agree with it. It's harder to find and yeah, the quality is really hit and miss. Sometimes I would, I make this small observation at some cafes that it's driven more towards coffee, but also serve matcha. I tend to look at the baristas brewing techniques a bit. Thanks to education from both of you that now I can judge a little bit.
Ryan And Sam (04:23)
Yeah.
Yizhou (Ben) Ma (04:23)
So
I don't order the drink as much, but I do see that's how it's being made in a lot of commercial places.
Ryan And Sam (04:30)
Apparently, the EU makes it very hard to let in anything that doesn't meet their standards for herbicides and pesticides and organic farming type criteria. And it's very stringent. And matcha needs incredibly nitrogen rich soil. everything likes nitrogen, so you need to use a of herbicides.
Yizhou (Ben) Ma (04:42)
Hmm.
Ryan And Sam (04:51)
pesticide in commercial farming. There are some people doing much more natural methods, but it's a smaller number and it's expensive. So most of the stuff that's for more B2B use, like in a cafe, there are actually relatively few options for what would be considered higher quality matcha due to the restricted farming practices.
Yizhou (Ben) Ma (05:12)
very interesting. Yeah, I didn't know this either. That could certainly be the reason then.
Ryan And Sam (05:17)
you also are a podcaster. You co -host a podcast on food and food technology called Food in the Hood. I want to talk a little bit about that.
Yizhou (Ben) Ma (05:25)
Yeah, sure. Thank you for giving me the chance to plug in my own podcast. I have a podcast with my college friend, Amanda Sia, that we talk a lot about food science, its current trends.
educational perspectives of food technologies in general, and some of the kind of newer upcoming technologies, such as cellular agriculture, plant -based meat analogs, and various other type of topics. Yeah, so we don't really have a production schedule anymore, but...
We're trying to push out episodes every two or three months, let's say.
Ryan And Sam (05:59)
a great podcast too. think you guys do a good job talking about not only the fundamental science but the application of it in industry. Quite eye -opening.
Yizhou (Ben) Ma (06:00)
Yeah.
Yes,
growingly because of both Amanda and I, our roles have changed over the years, right? We really started the podcast in 2018 when we were still graduate students in the US. But now Amanda is quite deep into the food industry as a professional. And I've had a few transitions in terms of academic positions. So yeah, the topics also changed along.
Ryan And Sam (06:33)
So we got to meet very recently. I was in France and you were in the Netherlands and we met halfway and met in Antwerp, Belgium. And we got chatting and you very kindly offered to use a machine that you had to analyze a can of matcha. Could you talk a little bit about what that machine does and the way the analysis works?
Yizhou (Ben) Ma (06:42)
Yes.
yeah, sure. Yeah, so, you know, if we're thinking of matcha, by the appearance of it, it's just, you know, grind up dried plant tissues, right, in the form of a powder. So a relatively common measure of powder, physically speaking, is its size, right, and its morphology or its shape or how it's looked normally under a microscope.
So at our university, we happen to have a device that kind of automate these process by essentially it's a automatic microscope that can look at different fields on a thin slide. So what we could do is to disperse the dry disperse, I mean, by air, a thin slice of matcha powder onto a glass slide.
and the automated microscopic system will then identify these powders and first take pictures of them and analyze its size and also save some of this information about its morphology. is it a rod shape or is it like a shape like a pin or is it a polygon or is it more like a circle type of shape? So that certainly matters.
not only for matcha, also has a even much wider use in, let's say, pharmaceutical, right? A lot of these active compounds were dried also in powder forms. It's quite important also for milling, right? So to mill a flour, for example, that's also powder that also comes in different shapes and different sizes. So that is...
what essentially I did for this matcha sample as well.
Ryan And Sam (08:31)
Compared to other particles, other food stuffs that you put through this machine, is it extremely fine or is it standard to some of milled cereals or other types of powders that you would come across when doing food research?
Yizhou (Ben) Ma (08:48)
Yeah, it's certainly on the finer side of the spectrum. So a lot of food powders are range. I will say this is micrometer, right? That's most of the kitchen ingredient size that we will encounter. So in terms of matcha, we're really talking about 5 to 10 microns or micrometers.
which is on the lower side of powders. So something, you know, probably in other type of powders that we're seeing in our life, it's perhaps in in the higher two digits or close to a hundred or several hundred in micron and that type of size is more typical to find in powder foods.
Ryan And Sam (09:31)
Interesting.
So to give our listener a little bit background information about this sample. So Ryan brought a a little sample of matcha from Horii Shichimenen. And it's from this special blend, Seishin no Shiro. So if you had the chance to procure it online or offline, you're welcome to, you know.
Buy one of these samples and try it yourself to have a better reference of what exactly did we test Yeah, so I will assume since this is from a traditional house This matcha is milled from a traditional ishi usu Yeah, especially for the price point too. Yeah, so from what people have been talking about so like people Would say that you know any matcha coming from a traditional ishi usu So usually has a more jagged
Yizhou (Ben) Ma (10:10)
Mm -hmm.
Ryan And Sam (10:20)
powder shape compared to a matcha that was milled from a ball mill. So for a more jagged powdered particle, it usually suspends better in water than a more satirical powder. So Ben, from your observation from the sample using the machine, would you say that this powder is particularly more jagged compared to other powder that you have seen? Or how do you assess the example for it?
morphology of this powder.
Yizhou (Ben) Ma (10:47)
Yeah, that's a very good question, Zongjun. Let's say what essentially this microscope does is it picks up these individual particles and take a quick picture of it. It's just a black and white picture, and then it tries to analyze its shape. And a common parameter that we can use for
these type of shape, for these type of morphological analysis, it's what's called circularity. So if we look at the multiple axes of this shape, how closely they are equal to each other. For example, a perfect circle, no matter which way we draw a diameter, it would always equal to each other. And in fact,
Ryan And Sam (11:21)
Mm.
Yizhou (Ben) Ma (11:29)
Well, at least from this measurement, we saw quite of a uniform, let's say, circularity measure. The mean circularity is about 0 .8. So that actually means it's quite high. There's not a lot of, let's say, se elongated particles. That is only, let's say, more of a jacked or more like a rod -shaped type of.
a type of morphology. However, it could also happen that there are some roughness on these type of particles that if we look from an overall perspective, it's still quite of a circular footprint. But there might be, let's say, spikes on them that could further change its morphological features, let's say.
Ryan And Sam (12:18)
Is there a way to measure that? Like the spiky features? Would that call for an SEM or would it be some other method?
Yizhou (Ben) Ma (12:26)
No, no, the same type of morphological analysis that we can dive deeper into that type of measurements. But then when we are starting to look for things like spikes per se, then it becomes a bit more, let's say, more subjective. And perhaps what we do typically is then to have some benchmarks.
So if we were able to compare two different type of matcha powders or two other type of powders that were made from similar processes, we can then compare and contrast directly from an image perspective to see how they're different. And that's probably a little more objective in that way.
Ryan And Sam (13:05)
Yeah,
natural next step probably we can offer Ben some other samples, milled from maybe the same tencha by using a ball mill or even using our Sanko mill. And then we can compare, you know, like how exactly are they different from each other.
Yizhou (Ben) Ma (13:22)
Mm -hmm. Yeah, that would be very interesting to do. I also have very limited knowledge about matcha so it's difficult to really assess some of these data that we see from a single sample. But at least they give us a very good starting point.
Ryan And Sam (13:23)
Yeah.
Hahaha, all over.
Yeah, something that I found very surprising in the data and specifically when you look at the distribution of particle diameters is that it's not a unimodal distribution, it's a bimodal distribution with a very small like hill, hump, well below one micron and then the other much larger peak is around seven or eight microns.
Which was interesting. Why are there so many sub -1 micron particles? Is this type of distribution normal for other mild things like cereals?
Yizhou (Ben) Ma (14:12)
Yeah. Yes. Actually for a, just a grounded powder, right? So, so this, didn't do any further separation of this powder. At least I don't think the, the, the, the matcha have done through many other type of separation processes. And it's the same for, for example, a chickpea flour. Or so we, we do a lot of research on chickpea and other pulse ingredients.
And what we typically see are these type of bimodal or sometimes trimodal type of distributions where one peak could correspond to a specific fraction or specific composition of that ingredient. And for chickpea, that's probably more straightforward. It has a lot of starch and it also has some proteins and the starch would show up as a different size in general.
the starch granules would be at a different size than the proteins so that you could see actually, yeah, there are two different fractions that you already could observe by just looking at its size. Yeah, so specifically for this, the matcha sample, there are very, very small particles that we're observing here that's below one micron. And one...
aspect that we should first disclaim is that that small of a size is touching the limit of the light microscopy that they could really assess and evaluate. So there could be some, let's say, systematic error there for evaluating these small particles. But on the other hand, if we're looking at the data and trying to interpret it, there are
probably a lot of sugars or other type of small molecules that were not part of the cellulose type of average powders that you will see at the larger diameter. But it would be something that's probably more pure, say, for example, just a sugar or just some other type of
know, organic presence of compositions.
Ryan And Sam (16:04)
Hmm. Very interesting. So this in theory could be driven by like the leafy leaf material or more of the veins or maybe if some stems got in there, you have some lignin. Or even like from a very high pressure milling, you probably broke a lot of cell wall and a lot of these compounds or smaller things coming out from inside the cell. Yeah, maybe.
Yizhou (Ben) Ma (16:26)
Yep, exactly. Yeah, that's probably where these, let's say, smaller molecules were released from. Normally, we expect them to be packed together. But they could also be broken off.
Ryan And Sam (16:39)
Interesting. So when it comes to bringing this back to the way this can impact matcha and its flavor, when you have particles that are this small, could you discuss in general the process of oxidation of any non -perishable food, let's say like from ground coffee or this or flour, and sort of what's happening there as a...
it gets exposed to the elements and how quickly it can go bad. Or not bad, or lose its sensory qualities.
Yizhou (Ben) Ma (17:06)
Mm -hmm. Yeah.
Right, right, right. Yeah, so, so, or in some extreme cases, they could just go bad as well. So this is really something that that's, think, quite unique to to matcha as a, as a, let's say a, a specialty drink, or it's, it's also a unique presence in the form of a powder, right, because we also have a lot of
Ryan And Sam (17:15)
Mmm.
Yizhou (Ben) Ma (17:29)
different type of powder ingredients in our kitchen cupboard. We could have, let's say, cornstarch that is in the similar particle size distribution as a matcha powder. But we're not really looking for it. We're not applying it for its pure, sensorial perceptions. It's normally used as a thickener. So when we have powders at this fine of a particle size, we essentially have
small particle size so that we have a very large surface area. So with very high surface area, it's prone to be oxidized quicker simply because there are more contacting points that can be touched by air or the oxygen in air. So that is something quite specific.
Ryan And Sam (18:08)
Mm.
Yizhou (Ben) Ma (18:11)
for these type of powder drinks. And in general, lot of other type of powder ingredients are agglomerated. instant coffee are not as fine as the matcha powders. that also can help a bit. Well, it primarily helps with dissolution, but it also helps a bit with reduced surface area.
Ryan And Sam (18:31)
Hmm. Makes sense. And to what degree do you think moisture can play a role in degradation of positive sensory qualities, flavors and aromas? Because a lot of people store their matcha in the refrigerator to preserve it. And then, you know, it's open and they scoop some out and they sift it and then they put it back in the fridge. But there's certainly some condensation going on. Do you think
Yizhou (Ben) Ma (18:40)
Mm -hmm. Yeah.
Yes.
Ryan And Sam (18:56)
over the course of, I don't know, 100 grams of matcha, you're going to preserve it as well because of the introduction of moisture versus having not refrigerated it. Like what's, what do you, just from like your first principles, how would you think about that trade off from a scientific perspective?
Yizhou (Ben) Ma (19:11)
Right. And this is really just off the top of my head that I have never really done much of research from a scientific perspective. But if we're just purely talking about first principles and following your train of thought, that first of all, all reactions, while most reactions really require water, especially oxidative type of reactions, requires water or water severely accelerates it.
All right, so essentially the moist environment in a fridge or some other type of environment that is high humidity certainly would promote some of these changes. And I would argue that in the fridge is probably OK because it's lower temperature.
But if it is a moisture also at room temperature or normal temperature would also promote a lot of microbial growth. So it's really not nice to have a lot of moistures around powder. Perhaps I would argue if you freeze it, now you go into a different problem. But then at least you're avoiding a lot of these water impacts when dealing or storing of.
of powder ingredients like matcha.
Ryan And Sam (20:23)
So freezing is generally a good idea. But then like when you open it every time, it's still you're to get some condensation. You re -close it and then it goes back in the freezer. So it's mostly liquid water. Yeah. I mean, once it goes back to the freezer, the water will crystallize into ice. Yeah, that's true.
Yizhou (Ben) Ma (20:23)
Yeah.
Mm
Exactly.
Yeah,
exactly. Yeah. there isn't too many good I would say, yeah, that's it would just be a very difficult situation to solve, right? That's why, you know, perhaps what, you know, coffee drinkers are now doing is probably very smart with with countertop grinders that you just make powders on promise. So to avoid a lot of them.
the trouble with storage, right? And that's using the nature itself to store. Well beans are, coffee beans are the natural ways of storing beans, right? The coffee beans themselves. that would probably make more sense to me than figuring out a very complicated type of storage solutions for these type of very sensitive powder.
Ryan And Sam (21:28)
We totally agree. Yes.
Yizhou (Ben) Ma (21:30)
Yeah, right?
Yeah, like these storage degradations is unavoidable if we're dealing with these type of fine powder ingredients.
Ryan And Sam (21:43)
Could you talk a little bit about the unintuitive behavior of powders and small particles when you get to the point where a lot of the cohesive forces are so strong that you get things like clump? Because what we've noticed in milling matcha is that in our failed tests,
when we didn't put a parameter right, where it wasn't very fine, it was like coarse sand. And one of the ways that we know it's working is actually that it's very sticky to itself. It clumps up. And there's this transition that happens at some point. So could you talk a little bit about like the chemistry and physics of that process in the food?
Yizhou (Ben) Ma (22:07)
Mm
Yes, a bit. What you're seeing there is essentially the cohesiveness of those powders are increasing. Essentially, there is more of a physics type of concept called packing volume. So for example, the volume ratio of the particles.
exceeds a certain volume ratio of the bulk volume that you would essentially get more densely packed structures that are kind of similar to a lump of powder in that regard. And a lot of times is also how there are also other type of forces that could play a role. There could be, again, moisture.
Right, so that could form a lot of water bridges essentially to have a lot of hydrogen bounding, to have the powder sticking together. And it could also be static, right? So there are some statics as well. So in general for the food industry, lumps are not good. Right, so a lot of times what a lot of milling experts or
Ryan And Sam (23:25)
I'm
Yizhou (Ben) Ma (23:29)
or grain scientists, what they're trying to do is to minimize as much of these lumps and to have a free flow powder as much as possible. So that really goes a lot with the morphology and the particle size of the powder ingredients. And sometimes also people are placing these flowing aids, right? So some inert particles that would just sit in between of the active particles and to break up some of these lumps.
Ryan And Sam (23:55)
Interesting. And so for people in the matcha industry and especially for barista to start preparing a bowl of matcha, they usually would use a sieve to unclump the matcha. So they put the, you know, the correct portion on the sieve and then they just sift it out and, you know, to make a more uniform matcha powder. Have you seen...
Yizhou (Ben) Ma (24:15)
Mm -hmm.
Ryan And Sam (24:19)
any other ways in the industry for other types of powder for people to unclump the powder or do they all use a similar kind of mechanism?
Yizhou (Ben) Ma (24:28)
Yeah, I would say in general, it's a mechanical force. sieve is certainly very practical and very good to use. At some industrial scales, when you can't sift things anymore, if it's too large or too small, sometimes piezoelectrics could be used to have essentially vibrators.
Ryan And Sam (24:48)
Mm -hmm.
Yizhou (Ben) Ma (24:51)
to help breaking the particles apart.
Ryan And Sam (24:53)
Interesting. That is interesting. I wonder if we can apply that to matcha. Yeah. Well, one thing you see the coffee industry doing, like anytime you're grinding anything, you're producing tons of static. So like electrostatic forces cause like matcha and coffee fines to stick everywhere. So you see people using ionizers, which I assume the mechanism there is it produces some ozone. It's basically a free radical.
Yizhou (Ben) Ma (24:55)
Mm -hmm.
Ryan And Sam (25:19)
which then helps neutralize some of these charged particles. How effective is that? Apparently it's pretty effective in coffee. I've never heard of anyone doing it in matcha, but I wonder to what degree, if you were to use a deionizer for matcha and produce tons of ozone, are you just destroying all the catechins and health benefits by getting it not to clump or to reduce those electrostatic forces?
Or do you think that there's probably way more antioxidants in the matcha than can ever be neutralized by something like ozone?
Yizhou (Ben) Ma (25:50)
Yeah, that's difficult to kind of say without running some experiments or thinking through the specific reactions. Yeah, then, right, right, right, right, right. Even for first principle guesses, I don't dare to comment too much specifically about how we would really interact with the antioxidants in matcha. But what
Ryan And Sam (25:59)
Yeah, well, again, first principle guess.
Mm.
Yizhou (Ben) Ma (26:14)
Perhaps we could think of is also, if dealing with these lumpy problems, whether we have a grind on promise, so to really grind it on promise, that would be a little bit easier to solve than these more long -term type of lumps that's forming during storage.
the mechanism or if we added temporal time component to it, it would be really difficult to estimate and simulate what would happen to that kind of macha during transportation, storage, then finally, rich consumption.
Ryan And Sam (26:50)
That makes sense.
makes sense.
Yizhou (Ben) Ma (26:51)
Yeah. Then what about James Hoffman's famous two sprays of water to the beans?
Ryan And Sam (26:59)
it has a really cool name.
Yeah, so it's called the Ross Droplet Technique, where you spray a little bit of water to help eliminate the static that gets formed during grinding. I have no idea if that would work with matcha. I have heard that it cannot be too dry of an environment or too humid.
Yizhou (Ben) Ma (27:04)
Mm -hmm.
Mm -hmm.
Ryan And Sam (27:17)
And
I think it's around 60 % humidity is what is considered the perfect humidity in a relatively cold room to mill matcha. Maybe that has something to do with it. I don't know.
Yizhou (Ben) Ma (27:31)
Yeah, that could be it. That type of work, it's more, again, do we really need ozone or these type of, let's say, a bit over engineered solutions? Or are there other ways that can work around with it to alleviate the problem here?
Ryan And Sam (27:48)
can you maybe talk a little bit about foam formation and the stability of the foam from a food scientist perspective?
Yizhou (Ben) Ma (27:57)
Yes, absolutely. This actually links very well with the particle size distribution that we were discussing. So Ryan asked about the small peak at a very small particle size, the submicron particles. And actually, of those, my suspicion is that they could also be protein aggregates. And protein certainly is surface active.
it is very commonly used to stabilize or first of all to create foam and also to stabilize foam in many types of food beverages. that actually would be quite interesting to observe here, Because matcha is such a young leaf, right? On the tea to have. So actually younger leaves tend to have a lot of more protein content in general.
compared to older leaves, just simply because they have more. And these proteins are in the form of enzymes. The enzymes are there biologically to help the tree to grow more. But from a food production perspective, we pick these leaves for other applications that are also a bit higher in proteins. So that could be seen here that the foams are quite nicely set up with a lot of these matcha -based drinks.
Ryan And Sam (29:09)
Hmm, interesting.
Yizhou (Ben) Ma (29:09)
Yeah, so I actually have a question to you two about this foam though. Because you know way more about matcha than I do, Because when I see this matcha latte type of drinks, do you think that most of the foams are coming from the milk or actually from matcha?
Ryan And Sam (29:25)
It can come from either. So definitely like the base latte art is coming from the foam of the milk. But any good matcha that's well prepared, you should have really nice foam contributing to the sensory experience just from the matcha itself.
Yizhou (Ben) Ma (29:40)
So then the top part is all milk foam from the latte art. then there will be suspended foams in the drink itself that could come from matcha.
Ryan And Sam (29:44)
Yes.
Good, yeah. Or, you know, it's textured milk to begin with, so there could be some suspended air from the, if the milk is steamed with a lot of skill.
Yizhou (Ben) Ma (29:52)
Mm
Hmm, I see. Interesting.
Ryan And Sam (30:04)
they say that matcha is a suspension because we're drinking the whole leaf. Could you put it in like a scientific descriptor of like what makes matcha so unique? As you you compare it to like instant coffee or even normal coffee. It's 100 percent soluble stuff for the most part. You're not actually drinking the.
Yizhou (Ben) Ma (30:05)
Yeah.
Mm -hmm.
Ryan And Sam (30:26)
insoluble stuff, but match is incredibly unique in that respect.
Yizhou (Ben) Ma (30:29)
Yeah, that's something quite interesting. When you mentioned it, most of our drinks, we tend to only drink the soluble part, meaning that it's a solution per se. So the simplest is sugar and water. It automatically would dissolve because of thermodynamics. But in this case,
For matcha, it's a suspension, meaning that it's not 100 % thermodynamically stable. So if we leave matcha out, leave the suspension out for a day or longer, it would start to phase separate. The solids will start to sink because of gravity, and the liquid, supernatant liquid, would become clear.
So that is something also I don't think it's that rare to have. It's just that we don't really have too many of these examples with pure solid particles. Because for example, if we're drinking milk, the proteins in milk are in the form of casein micelles. And they're also suspensions of their dispersions. So they're even at a smaller scale.
of these particles dispersed in the system. So they're not 100 % dissolved in the system because they're also not 100 % thermodynamically stable. But we're more familiar with those because they are probably a bit more, let's say, commonly found in various milk type of products so that we're OK with drinking them.
more easily, where we don't overthink of this process.
Ryan And Sam (32:14)
Wait, so they're micelles. The proteins in milk are micelles.
Yizhou (Ben) Ma (32:19)
Yes, The casings are in micellar forms.
Ryan And Sam (32:20)
Interesting.
I went to a talk, I don't know, when I was an undergraduate studying chemistry and they were talking about using my cells for certain type of like ultra targeted drug delivery systems. And I like very clearly remember this talk. I had no idea it was a natural phenomenon, but it could be in something like cow's milk. It's surprising.
Yizhou (Ben) Ma (32:34)
Yeah.
Yeah. Yes,
yes, yes. It is a natural phenomena. And we kind of take, we normally take natural phenomena for granted. Yeah. In many ways. Yeah. Yeah. But then, but then if we think, again, I'm just, I'm just also kind of thinking out loud here, right? Because a lot of, let's say, freshly made soy milk, certainly,
Ryan And Sam (32:51)
Yeah
Yizhou (Ben) Ma (33:04)
there are some particles that are suspended inside of the drink, the liquid system. That were just kind of consumed also with the rest of the liquid. So you can argue that it's a complex system that has some part is a solution and the other part could be also a suspension. So there are solid particles included. And if we let that milk, the soy milk, sit
overnight or sometimes we do see sedimentations as well. So that is the similar phenomenon that we're seeing here, except probably for matcha, the uniformity of the drink, it's much more prioritized.
Ryan And Sam (33:34)
Yeah.
never seen someone produce a successful CPG consumer packaged good RTD ready to drink bottle of matcha. I've had a lot of them. They all have the sediment problem. But you know, something like soy milk or oat milk, they tend to not have a lot of sediment. Do you think that could be overcome in the tea industry by just using emulsifiers or gums?
something like lecithin or do you think the particles might just be too big and it's still gonna sink?
Yizhou (Ben) Ma (34:15)
Yeah, I think it's unavoidable with if it's just water and matcha powder, right? that, but even with added, let's say modifiers or technologies, the reason why the drinks are seeing the plant based milk drinks are seeing more uniform, it's also because that the color or the flavor that's given into the drink.
came from the fat fractions. So they are stabilized via an emulsion type of mechanism. So that fat droplets are stabilized by these gums or emulsifiers. But it's very difficult to suspend solid particles because they're relatively inert. we don't have other type of compounds that could interact with them well.
with both the solid and water to really keep them afloat for a long time. So that's probably the reason for any type of matcha drink to have an expected level of sediments on the bottom.
Ryan And Sam (35:06)
interesting.
I have a question just to be validated. there's in Japanese tea ceremony, there's two types of tea that can be served. called Usucha or thin tea. And the ratio of matcha powder to water is one to thirty, one gram to thirty grams of water. And there's something called Koicha where you cut the tea in half. I'm you double the tea and you cut the water in half. That's four times more concentrated.
And there's almost zero foam that can form. It's basically a paste. And the reason there's no foam formation is just because the viscosity is way too high to support that foam. Is that the correct conclusion about why there's no foam? Most likely.
Yizhou (Ben) Ma (35:54)
and both types of teas are properly mixed and there were four distinctions.
Ryan And Sam (35:58)
Yeah, full suspensions. should be like proper suspensions.
Yizhou (Ben) Ma (36:02)
Hmm.
Yeah, it could be. And also maybe the amount of available water that just simply do not, if it's more behaving like a paste, you wouldn't have enough available water for let's say protein to unfold or to have the proper interfaces for stabilizing foams essentially.
Ryan And Sam (36:22)
Hmm.
Ben, I have a follow -up question regarding to koicha do powder behave differently in a like a usucha kind of very water -abundant situation versus a taste situation? would, you know, would segmentation happen also very easily if it's a paste, for instance?
Yizhou (Ben) Ma (36:42)
It.
Maybe a little bit less if we're thinking specifically for matcha, right? Because if it's a paste, the solid particles actually contributes to part of the structure of the overall product or the drink that you made, right? Because there are also particle -particle interactions. And in a more water -abundant or a liquid system,
Ryan And Sam (37:05)
Hmm, well...
Yizhou (Ben) Ma (37:10)
there are less particle -particle interactions, but more particle -water interactions in general. So in that sense, there could be a difference. And in terms of sedimentation time, that certainly also relies in these type of liquid or semi -liquid systems. It's always viscosity plays a big role. And the reduction of water typically would
would increase the viscosity of the water phase simply because there are some soluble fibers in the matcha powder itself. And the more concentrated that fraction is, the higher the viscosity would
Ryan And Sam (37:46)
Very interesting. Maybe koicha will be a better CPG product idea. That's more shelf stable. Not that I really enjoy koicha. The intensity is off the charts. Yeah. I can't imagine what it's like to when it becomes a stale product. my God. Or at least not even fresh. Like, I don't know.
Yizhou (Ben) Ma (37:47)
Mm -hmm.
Yeah. Yeah. Yeah. Well, that's, that's a high, that's a high tasting bar.
Yeah.
Mm
Ryan And Sam (38:10)
Yeah. All right. So I guess before we end, you have any questions for us?
Yizhou (Ben) Ma (38:15)
you know, not too many. I think, yeah, probably just more as a comment that I really enjoyed following your ride and seeing a lot of the development from Sanko and, you know, I hope to see more of, to have a chance to analyze more of your products.
Ryan And Sam (38:30)
Thanks. Actually, I have to give you an extra special thank you, Ben. You were one of the very first phone calls I made in the first week or two of the idea of the company, trying to figure out and get the confidence of, is this a technically solvable problem? Can you mill matcha fresh in a machine that's in the footprint of something like a coffee grinder?
And you pointed us in a lot of very useful directions in the beginning of where to do research and learn about milling science. So, you're a huge thank you. Yeah, thank you, Ben.
Yizhou (Ben) Ma (39:02)
No, you're very welcome. The ride still continues, right? So I'm very happy to see it.
Ryan And Sam (39:07)
That's true.
And we really appreciate you analyzing the sample. It's very cool.
Yizhou (Ben) Ma (39:08)
heart.
Yeah, you're very welcome.
Ryan And Sam (39:11)
Hopefully
the slice of pie of your beverage chart will grow bigger in the future as we become more successful. We need to send you a matcha bowl We'll send you a matcha bowl and a whisk. And we'll lower the inertia of preparation to make that pie chart
Yizhou (Ben) Ma (39:30)
Yeah, no, yeah. Thanks. Thanks a lot.
Ryan And Sam (39:32)
well, thank you so much, Ben. I think that's all we have time for today, but we really appreciate you being so generous with your time. if you enjoyed this podcast, please consider giving it five stars or sharing it with a friend. And we'll see you on the next one. Thanks. Stay tuned.
