Thursday Nov 04, 2021

Niny Rao and Mark Shapiro on The Science and Taste of Coffee

Niny Rao, PhD is an Associate Professor of Chemistry and the Director of the Undergraduate Chemistry and Biochemistry Program at Thomas Jefferson University College of Life Sciences. She received her bachelor degree in chemical engineering from the Cooper Union for the Advancement of Science and Art in NYC and went on to pursuit a PhD in physical chemistry at Florida State University. A computational chemist by training and an enthusiast of artisanal food and beverages, she has expanded her research into food chemistry. She co-authored numerous research articles on the impact of brewing, roasting, and bean origin on the chemical composition of cold brew coffees. Dr. Rao has been an educator since 2007 and is an advocate of Jefferson’s undergraduate research program, mentoring undergraduate researchers in chemistry. Her students have presented their research in both regional and national conferences on topics ranging from the computational study of zirconium methyl amide to the chemistry of ready-to-drink coffee beverages.

Mark Shapiro, MD is the creator, producer & host of Explore The Space Podcast, a show focused on bringing those who provide healthcare and those who seek healthcare closer together through conversations with leaders from across the spectrum. He is also a TEDx speaker, delivering his first TEDx in March, 2021, and is a co-author of the “Covid-19 CV Matrix”  as seen in the Journal of Hospital Medicine and Proceedings of the National Academy of Sciences Dr. Shapiro has been in full-time clinical practice as a Hospitalist since 2006. He earned a BA in history at University of California-Los Angeles, attended medical school at Baylor College of Medicine and completed his Internal Medicine residency at University of California-San Diego. Dr. Shapiro is an active voice on social media and can be followed on Twitter at @ETSshow & Instagram @explorethespaceshow.

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coffee, beans, drink, taste, roasted, cold brew, grind, people, flavor, extraction, extract, acidity, bit, caffeine, brew, podcast, cold brew coffee, buy, acids, compounds

SPEAKERS
Resa Lewiss, Mark Shapiro, Niny Rao

Niny Rao  00:01
So when you have a low temperature, a lot of the bitter, larger chemical compounds are not soluble in water at low lower temperature so they're not coming out very often. They're the one responsible for the bitter kind of exchanging taste that we taste in coffee. So what we are tasting in cold brew, it's probably the lack of bitter acids, as they call it, and then we give you that little bit better, smoother taste.
 
Resa Lewiss  00:25
This is the visible Voices Podcast. I'm your host, Dr. Resa Lewiss. Before we get started, here's a word from the creators of the voices Unheard podcast.
 
00:35
Hello, listeners. This is Dr. Pringle Miller. And I'm joined by Dr. Melissa Blaker voices our podcast recently launched and we are very excited. three episodes are now available for you to download on Apple podcast and Spotify. When you go there, be sure to hit subscribe voices on heard as a podcast production of physician just equity.
 
Resa Lewiss  00:56
Hi, listeners. Thanks so much for joining and I'm really excited to bring you today's topic. Coffee. I love coffee. Okay, my subject matter expert is Dr. Niny Rao. She's an associate professor of chemistry and the director of the Undergraduate Chemistry and Biochemistry program at Thomas Jefferson University, College of Life Sciences. She came across my radar when I read a food and wine magazine article where they quoted her and her work on cold brew coffee in her lab and with her students, many studies, cold brew and hot brew coffee, the temperature of the water you should use grind of the bean and roasted the bean all with an eye towards health and other extractive effects. I just made that word up extractive. My guest conversationalist is a serious coffee hobbyist. Dr. Mark Shapiro, you may know is the creator, producer and host of explore the space podcast. He focuses in his conversation on bringing those who provide health care, and those who seek health care closer together. So as a little bit of background, Nene shared that in the morning, she likes to drink coffee. That's a pour over Mark likes to work on his skills with the AeroPress and me, I like to pull shots of espresso and make believe that I'm a barista. So a little background regarding Resa and coffee. Growing up I wasn't allowed to drink it, I was told that it would stunt my growth. Now at the tall height of five foot two inches, we can just say that there really wasn't any science to that. Nonetheless, I sidestepped the rules by definitely eating coffee I screen, selecting coffee flavored hard candies, and drinking coffee milk. Now if you attended Rhode Island Public Schools, you will know that when you bought milk, you had the option of milk, chocolate milk, or coffee milk. I don't think there was anything natural or anything coffee really in there. However, it definitely tasted good. And with that, let's get to the episode. Now nidi get us started cold brew versus hot brew.
 
Niny Rao  03:00
So we are, we were looking at how, at the time the corporate coffee was becoming very popular, you go to any coffee shop, but they have all these extravagant setups about the color corporate coffee. And I looked into a little bit more about cocoa coffee, it just turns out that for COBRA coffee, you're brewing coffee at room temperature were lower. So you use cold water, you let the grind feed for a long period of time, by often overnight 24 hours, some people do 48 hours, and then you enjoy the X extract, filter it and then the extract is what we call cold brew coffee very often needs to be diluted with water. So that's we in we stumbled on this topic because I always like to think I could make it myself. I could do it in my kitchen and do it myself. And it turns out it didn't turn out correctly. It was too strong too. Not much of a flavor. And I was wondering if I did something wrong. So I looked into the brewing methods a little bit more and I convinced my colleague to join me to do some chemical analysis on COBRA coffee, it turns out there was nothing to compare to and that's how we started. And that's how we started looking into the extraction mechanism as well as the kinetics like how long does it take for the coffee to be extracted? And we looked at two specific compounds chlorogenic acid, which is an antioxidant, and the caffeine which everybody who drink coffee says okay, what is the caffeine content? Right? So, so as we were studying this, we realize that this is there's it's a great opportunity for us to fill in some void in the coffee region. Most of European coffee maker brewers as well as a South American coffee, kind of source they pride themselves on Drinking hot brew coffee, espresso, filtered, mocha. And Kobo seems to be very popular in North America. And we want and then people started talking about, oh, he has like low acidity, he has smooth flavor and another cup, and texture. And we just wanted to give some metrics to the audience to the consumer about what they can like exactly what these words mean. And we were able to that started the whole thing. And the first one we looked at was the kinetics of extraction. How long did it take for the chemicals to come out of the grind? And it turns out, the way we're doing it seven hours is more than enough. And then the other one we were trying to decipher was, was, is there a difference between roast and versus in cold brew coffee, and the first one we thought there was something by turns out, it was a little bit more inconclusive. Our latest study actually deciphered that aspect of cold brew coffee a little bit better, we actually roasted our own coffee, we bought a roaster, we started doing like, we made sure that we had the same sorts of beings, and we roasted two different types of three different temperature to see some of the characteristics change. And then we found interesting stuff. So yeah,
 
Resa Lewiss  06:27
so I want to go into some of the specifics of the science and I think our audience is probably and health minded audience, Mark, if you had to pick light rose versus dark roast, which one would you go with,
 
Mark Shapiro  06:40
like,
 
Resa Lewiss  06:41
always like, and cold brew versus hot brew.
 
Mark Shapiro  06:44
So I've done my own cold brew a couple of times couple of different ways, the flavor is fine, the flavor profiles are fine. I feel like the flavor profiles I get when I do a lighter roast. And when I when I say light roast, I'm talking about specifically just after what's known as first crack in the home roasting process. So when the silver skin blows off the temperatures at about 400 degrees for the bean. Second crack, for me is a no fly zone. That's what is known in the commercial marketplace is dark roasted coffee. But that's when you've taken all of the fun, interesting heterogeneous properties of the bean away and just turn it into a homogeneous, Dark Roasted taste that we're all pretty used to and that is readily available. So you can take different beans, put them all together, roast them to that degree and they're all going to taste the same. But if you're doing a single origin to go that far, you're kind of obliterating all of the good stuff. When you do a cold root when I do a cold brew. I find that I can't get the flavors that I seek to really be emphasized and to do cold brew properly. For me, it uses a lot of beans. I don't feel like I get enough bang for my buck with it. I have unfortunately the couple times I've done it as well I feel like I've kind of over extracted it and it gets a little bit of a little bit of a bitter taste that definitely washes out the stuff that I want I'm comfortable getting with my roaster I'm pretty tuned I can identify first crack the gap is there a stop at a cool it I let it sit a grind a drink it and I am I'm in heaven daily so I'm perfectly content there.
 
Resa Lewiss  08:12
Mark are you at all like me? When the medical literature puts out articles on coffee you look at the results. Oh my gosh, yes. I'm more productive. Oh my gosh, less depression less prevalence of dementia Do you do you care at all about the medical or it's all about pure taste?
 
Mark Shapiro  08:26
i It's not that I don't care about it. I do. I feel like a lot of those things are released in a manner where they land on me it's just being clickbait. I don't feel like we have something to say that. Absolute Yes. Absolute No. All things in moderation. I don't drink extraordinary amounts of coffee. I enjoy one cup in the morning, I might have a second cup in the afternoon. I enjoy sort of what's available if I'm at work, and I don't overthink it. I enjoy it and I don't need a lot of it. So I don't really per separate too much on what one or more studies show. They are always on the top of a crawler whatever feature on New York Times Twitter, it's always there. It always just feels kind of clickbait to me. All things in moderation. Enjoy what you like and go forward.
 
Resa Lewiss  09:11
Yeah, meaning what? What are the facts regarding the health effects of coffee?
 
Niny Rao  09:16
Well, I there are a lot of one of the things that the most common ones that we know is that caffeine actually is a stimulant, and is one of the key like legal stimulant that you can use, like accessible over the counter and then you have a U shape right? So you were talking about the benefits, you know increases as you consume moderate amount as you drink more and more and then it becomes actually not beneficial to you anymore. And this same thing with acidity in coffee in the beginning that the nice flavor the small acids like the citric acid and whatnot, gives you a nice flavor in your mouth and you enjoy it and then you can drink too. much you may upset your stomach because the large amount of acid that you're, you're drinking so these are some of the ones that I've seen over and over again in literature saying like the acidity as well as the stimulant effect of coffee. It's the most prevalent in coffee drinkers. It's like most important to a lot of coffee drinkers.
 
Resa Lewiss  10:23
You mentioned in one of your posts, or perhaps it was one of the podcast discussions I listened to that the science is still not robust on pH and stomach and people that have gastritis, gastric reflux, reflux and the acidity of coffee. What do we know about this?
 
Niny Rao  10:43
So um, if you depend on how coffee is prepared, you will end up with a different acidity in coffee. Origin of coffee will also impact the acidity of coffee slightly, but there is a variation of acids that that can be extracted roast is a huge factor in terms of what kind of what kind of coffee you produce in terms of acidity. Our last study we did a being single origin beans from Colombia, and we roasted at three different degrees. One is right before right about the first class one is a little bit more than, like between the first and the second mark, I know you're talking, you know exactly I'm talking about and the third one, we roasted beyond the second crack to the point where the beans eject automatically before it turns into carbon. Because we wanted to show the spread, right. And you can definitely see the acidity change. And the more believe or not the lower acidity ones actually are the ones that are dark roast, because you actually roast all the chemicals out of it. Right. And then the higher acidity ones are the one that's medium and that's the one that most people enjoy. And, and also, we found that Cobra definitely has a lower acidity then hopper. Again, the extraction is when you when you extract anything with a high energy fluids like boiling water, we also did it with at the extreme we use boiling water which you never do when brewing coffee. And you actually get a lot of acids out of the beans good or bad. And you do have that metallic taste that that and then the strong acid taste when you're extracting coffee using boiling water so you do see the acid change from one to another we're getting a little bit better understanding in terms of how pH and acids are changing in different brewing methods. So in terms of acid reflux versus drinking coffee, still there, they're not. There's no definitive correlation yet I have not seen a paper saying like there is a correlation if you should. Everybody tells you to drink in moderation, but there is no definitive evidence saying drinking less coffee or drinking more coffee will either negatively or positively impact your app, the effect of acid reflux.
 
Resa Lewiss  13:14
I do know that when I drink cold brew, it tastes smooth to me it's easier to drink, it doesn't burn my stomach as much it am I drinking and sensing the fact that the pH is higher meaning it's less acidic or is that not the right correlation. Oh,
 
Niny Rao  13:32
there is some to that. And then we also think that the because it's extracted a low temperature some of a lot of the compounds are sensitive to temperature will come to extraction, so we'll call solubility. So when you have a low temperature, a lot of the bitter larger chemical compounds are not soluble in water at low lower temperature so they're not coming out. Very often. They're the one responsible for the bitter kind of like astringent taste that we taste in coffee. So what we are tasting in Cobra is probably the lack of bitter acids as they call it and then we give you that little bit better, smoother taste. I as much as I drink. Like I study Kobo, I don't drink coffee or coffee. I drink coffee or coffee. Yeah
 
Resa Lewiss  14:22
ninny. I want to ask a little bit about Grindr the bean because that's also been part of your research tell us about how that affects antioxidants extraction taste.
 
Niny Rao  14:32
It's mostly about extraction process. The larger the particle, right there are few things going on in in. So I'm gonna start about size. The larger the particle, the easier it is for the chemicals to leach out when you let it soak for a long period of time. So basically extraction is nothing but to take the chemicals from the grinds and put it in water and we drink the solution that is infused with chemicals. So on If you have a larger particle size, very often you will have less extraction in the same amount of time. Because you can't take a while for some larger molecules to migrate through. This is what we've seen we in terms of caffeine, caffeine is a fairly large molecule. And if you have a larger grain size, and you it will take a little while for the caffeine to reach equilibrium, as we call it, like saturation point, so forth. And then so if you have a finer Brian's that the powders in the bottom, like when you drink coffee, and you these, these powder will continue extract if they're left in the in the solution. So this is why I don't drink coffee who set for a long time, because you see them look, you know, in the bottom, and that's and that makes the coffee bitter because it's over, it's already extracted, because you let it sit for a long time and then all this good or bad they are all the stuff are coming out and then it's not it's not great tasting. So that's number one number two roast has something to do as well. As you continue to roast the beans, you are cooking the beans. By cooking the beans, you are changing the cellular structure of the beans become make more brittle. So darker rows tend to be easier broken into smaller parts. As a result, you have more fine and a little bit that bitter kind of like Mark said a taste. Right? So you are you're also depleting the depleting some of the chemicals as well. So roasted will also have the effect the size affects the extraction process of the beans and then I drink medium roast beans. And I if I were to do it my way, I'll actually sip the coffee before I make a brew the coffee. But I don't have time. Yeah, have you
 
Mark Shapiro  17:03
ever put beans that you've under roasted a little bit through your grinder and have your grinder bind up because that's a fun experience. You're hearing normal and suddenly, it'll hit a bean rare, you haven't depleted the matrix enough. And the burble will bind up and it goes into just start screaming. So if you want to really scare the dog, the kids, your partner, that's a great way to do it.
 
Niny Rao  17:26
I have not encountered that yet. And I do know that we did purposely underwrote some beans in the in previously and then I read it and one of the colleagues who did the coffee research on grinding is put the beans in the freezer before he went he will reduce the chance of binding happening. Also make the make the grind size a little bit more uniform. And that was and then somebody else told me that if you're doing really under roasted beans, like almost green beans, you freeze it with liquid nitrogen and then grind it that will make sure you grind the whole process into whatever size are you looking. Yeah.
 
Mark Shapiro  18:14
Can I ask you about the So can I ask you to validate or or rebut what I I'm asked a lot about how do I optimize my cup of coffee? What tech should I buy? What equipment should I buy? And I always tell people, whatever resources you have, put them into your grinder and get a burr grinder not a blade because like you said you want a nice consistent grind. But you want to get one that doesn't generate heat or generate excess heat while grinding because that excess heat will actually you've spent 18 bucks on 12 ounces of you know delicious beans from wherever. If you put those through a burr grinder that's grinding and efficiently in generating heat. You're actually going to scorch your beans as they go through your grinder Am I Am I on track as I give people that counsel
 
Niny Rao  19:00
you are you are on track you the grinding does generate heat but then my point has been when you depend on how much you grind at a time. If you're doing just like a one or two servings, okay, four servings in my household in the morning, you're going to be okay because you're all only grinding for about 10 seconds or even like 15 seconds at a time you're not going to generate that much. But if you're talking about batch processing the entire pounder so absolutely you don't have to worry about especially the heat generates later stage. So the part that the top layer that are falling onto the container that you're storing the coffee it's likely to be the one that's a little bit more roasted compared to the freshly the first couple seconds where it's still nice and cold. And in grinding it should be not It shouldn't it should be minimal at the time but I still believe like freezing the beans would probably be a better way of go
 
Mark Shapiro  19:58
to go tricks of the trade I'm totally trying that. Absolutely.
 
Resa Lewiss  20:01
For people that aren't as versed as this current group of convert conversions. And what might surprise people geographically about coffees of the world, where they are, where they come from.
 
Niny Rao  20:15
So we whenever we talk about coffee, Mark, like we talked about the big regions like Brazil, Colombia, and then the little bit more petite, Ethiopia, a lot of the coffee actually grown specially Robusta coffee, which is very often used in like instant coffee or not grown in Vienna. And India also produced coffee. And these are the areas that we do not think of coffee producers, yet they produce. I think Vietnam is the second largest, if not the first largest, robust producer in the world. So they that's one of their cash crops, because they are, they're located in this what they call the coffee belt, where around the equator region. And then they, I'm sure there are smaller farms that produce artisanal coffee that we don't, it's underappreciated.
 
Resa Lewiss  21:14
And for people that don't know what robust is
 
Niny Rao  21:17
so robust it is. So there are two types of coffee that's popular grown robust versus Arabica. Arabica tend to be grown at a higher altitude, and a little bit more as a smaller, lower, smaller production, little bit more fruity, and then less coffee. But it's the taste that we're going after the coffee tastes are going after, whereas robust is more disease resistant, easy maintenance, it can be grown like a low altitude Bush, like and then huge production. And, and then they, they, they have lots of coffee. And so very often Robusto are used to produce instant coffee, because you're not really going after the taste, you're going after the generic coffee, flavor, and then the coffee. So
 
Mark Shapiro  22:05
here's what I would say as far as regions, and superiority of one region or another. Coffee, as we all know, right? This is a multibillion dollar enterprise, all of these things that we have come to understand as being one region is good one region is not as good one region is the best. This is all marketing, it is all marketing, it's done by large entities that have been doing it for years to try to draw you to their product, it is not based. In fact, coffee, the best coffee is the one that you like the most, they are all available, go and try them. And then remember this to coffee, like any other product is seasonal. So there will be times of the year where the place that you like your coffee from, it won't be available. And if you get it from that region at that time of year, it will be suboptimal. It's like buying peaches in the wintertime, they will not be the ideal peach that you will get in the summertime. Is that that is the mathematic that when people ask me about the coffee because I look I love talking about it. That's what I always encourage people just go try them, go to coffee shops, pick the single origin. So you can say okay, this is what this is Rwanda, this is Guatemala, try them the one that you like, that's the best one. It doesn't matter if it says Colombia is the best or coffee from Yemen is the best or coffee. That is all marketing. Pick the one that you like, taste it, enjoy it, recognize the seasonality of it and be versatile. In the wintertime, I'm going here in the summertime, I'm going here, you'll get better prices, you'll have a much better experience and you'll be drinking the stuff that you love.
 
Niny Rao  23:43
It's always I always tell people, the one you're just like you said the one you like is the one you know, that's the best coffee. It doesn't have to be some people say Oh, this coffee is like 3040 $50 a pound. And the one I can taste the difference between that and my $15 pound or even $8 a pound coffee. You know, I enjoyed that one, it's accessible to me and I know I could have a chemical consistent product like an extraction out of it. And it's not only the product, it's not only the beans itself is also the extraction. Like you can ruin an expensive bag of coffee by roasting over roasting it or seeing it or you can ruin it by pouring boiling water into it and then basically over extract the coffee and then you were like well this. I paid this much but it doesn't taste like what I expect it to be. It's probably because of water temperature, the water the quality of the water, the deep the presence of minerals in the water. A lot of factors influence the taste of coffee influence the extraction of coffee, so I don't want people to get flustered. traded when the first time they brew coffee in there like it doesn't taste much, tweak a little bit, try it again, you know, and then you will find that sweet spot that you like. It's not nobody else's coffee is yours, right.
 
Mark Shapiro  25:11
And remember to the keeping the circuit through which you get bean to cup, as simple as possible. And as clean as possible. Oftentimes people will buy very fancy equipment, lots of bells and whistles, impossible to keep clean coffee leaves residue, wherever you use the term muck, perfect, I'm going to adopt it, but I'm going to give you credit, it leaves muck everywhere. And so if you have a complex circuit with lots of turns, small diameter tubing, you'll never be able to keep it clean. And that muck, the flavor from that will extrude into your brew. My favorite is pour over single cup, or AeroPress super simple system is easy to keep clean. I mean, it's just, it's clean. But that if you have a system that you can't keep clean, that will absolutely permeate your $25 Delicious executive coffee and it will spoil it.
 
Resa Lewiss  26:04
Dini, what's upcoming in your research, what should we look for,
 
Niny Rao  26:08
we're looking into a couple other compounds in corporate coffee that has been seldomly mentioned, mostly related to flavor. So one of the group of compounds of fluorescent, they are related to flavor. And they are a lot some of them are generated during the roasting process. So just one of the things we wanted to look at just to definitively to say that, Oh, cobras in the coal extraction method, you don't really get a lot of the compound out, compared to the heart extraction method, just one of those things we wanted to be able to provide data to is nothing like complex, but kind of COVID Stop that altogether, and now have to go buy additional beans, because I'm pretty sure the green beans I have right now are sale because they're not stored in, you know, airtight containers. They're in my lab, and it's been there for over a year. So that's one thing. And the other one, I was hoping to this is this may or may not be published, I was hoping to help a local things Indonesia, one of the family, friends, new farmer, coffee grower in Indonesia, and then they are just calling regular Arabica beans and then they wanted to kind of have the antioxidant and acidity tested to kind of give them an idea of how their beans compared to other beans, like from a very chemical analysis perspective, and not talking about copying at all. So I wanted to help them out on that one. And then hopefully, if I could have a couple undergraduate students who are interested in these kinds of things that we could probably publish a little small paper and just to just, you know, to encourage local growth of like support local growers and then give people an idea of different smaller, smaller farms, even within different regions will perform, produce very different coffee. And again, support the idea what you like to drink is the best.
 
Resa Lewiss  28:16
What a fun and informative conversation. So here are the take home points. Drink what you want to drink, whatever tastes good to you is what tastes good, hot brew cold brew, know that you're getting some antioxidants, some caffeine. And from my perspective, it definitely makes you more productive. Thanks for joining, and we'll see you next time. The visible Voices Podcast amplifies voices both known and unknown, discussing topics of healthcare equity and current trends. If you enjoyed this episode, please rate and review us on Apple podcasts. It helps other people find the show. You can listen on whatever platform you subscribe to podcasts. Our team includes Stacey Gatlin and Dr. Giuliano deport you. If you're interested in sponsoring an episode, please contact me Resa at the visible voices podcast.com. I'm based in Philadelphia, Pennsylvania, and I'm on Twitter at Resa e Lewis. Thank you so much for listening and as always, to be continued



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