Sci-Q: San Diego Experts Talk About The Science Of Cheese
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September 28, 2015 1:12 p.m.
Sci-Q: San Diego Experts Talk About The Science Of Cheese
Rachel Dutton, principle investigator, Dutton Lab at UC San Diego
Robert Graff, cheesemonger, Venissimo Cheese
Related Story: Sci-Q: San Diego Experts Talk About The Science Of Cheese
This is KPBS Mid Day Edition IM KPBS. Preparing food is an art but it is also very much science. The simple act of making a cake reckoning sauce involves principles of chemistry and physics. Perhaps no one to incentivize how scientific principles can influence what we eat is the making of cheese. In new lab the just moved to UC San Diego is using cheese is a way to understand the way in microbes work. So we are dedicating this addition of ours's IQ series to the explored the science of cheese. In joining me is Dr. Rachel.and she is headed that in lab which researches the microbial ecosystem of cheese. Rachel welcome to the program.
Innkeeper have any.
Also here is Robert Kraft P is the Academy of cheese mentor with venison mode cheese. Openness about twisting of science of cheese event with Dr. Dutton this week. Robert, welcome.
Thank you for helping me.
In your brought in a magnificent cheese tray.
Hope it is not too smelly.
No, it is very nice book runner my first question to Robert is to you and it's very basic. And other variations of a symbol of how she's made?
Very simply cheese is mean I -- made Bible person happens the middle comes into the cheese maker. The morning and afternoon twice a day the animals are milked twice a day. The person cheese maker does usually in this country is pasteurized milk. The next thing they do is add cultures and run it that's going to turn the milk into curds and whey the Kurds are the solid the way is the [ Indiscernible ] unlike nursery rhyme to -- to make them cheese and they're going to tweak decoratively different ways to make 1 million thoughts different cheeses.
Have a different cheeses are there Chemex direct 10,000 probably. We have had about 5000 at least in a shot.'s back to the phone to some groups?
They do go I would broadly characterized them as Bree cheddar Gouda Alpine blue and one string or stinky.
Stinky, okay. Now Rachel Dotson had you happen to study the microbes of cheese?
Yes it was around six years ago I was finishing my PhD in microbiology and I became very interested in microbial communities and wanting to understand how these microbes interact with each other out in the environment. And when you think about an environment like the soil or the ocean or even the human gut we have hundreds of thousands of species of microbes living together and I wanted to be able to find a simple system where I could sort of take apart those communities and put them back together in the lab and really distract how these microbes are interacting with each other. And I haven't also be very interested in food on my own and doing fermentations at home and reading about the science of realized that all the things I was looking for and experimental system could be found in fermented foods and I can't imagine a more interesting fermented food than cheese and so I completely switched my research career to focus on what microbial [ Indiscernible ] of cheese and it's been it amazing ecosystem to study.
What changes do mold make in the way cheese tastes?
Yes, so they have huge impact in the wake cheese taste. So have a couple of really interesting molds.
Yes you have the blue cheese.
Yes, so blue cheese is actually inoculated with a mold that is called Penicillium grow Coty.
And is it what is called the short makes the blue?
Exactly Soucie the veins in the blue cheese that is the [ Indiscernible ] mold growing inside the cheese.
Okay. I'm going for the most.
Great Emmitt is growing inside the cheese it like this will veins because the just little bit of oxygen, a little bit of air in the vein set really like the impairment with check which the cheesemakers craving for it when it grows it's actually one of the things that's doing to create flavor is breaking down the fat in the cheese so it sort of is eating the fat and in the process of eating the fat in the cheese is producing all of the sort of peppery spicy check
Right that is what I'm facing.
So those are free fatty acids of the mold is producing and then it also is producing a lot of very small molecules called volatile molecules and one of those is the smell of blue cheese so sexy called to have to note and when you smell blue cheese you know you are smiling blue cheese and you can recognize it is because we can actually recognize this molecule that the mold is producing while it is grown in cheese.
Usually multiboot meets bad inedible food. So Rachel what makes multi-cheese different?
Yes, so it's just a whole world of fermented food is fascinating because it's an example of where humans over thousands of years have figure out ways to cultivate populations of microbes to do something beneficial. So in the case of many foods you would think that encouraging the growth of bacteria and mold would be a good thing but with fermented foods we are creating very specific conditions for regulating the temperature and moisture and salt and acidity that encourage the growth of specific types of microbes that not only help us preserve the food also introduce all of these interesting flavors and textures and aromas.
And how Robert or the molds introduced to the cheese? What part of the process does that happen?
That can happen at many parts of the process. A lot of times it happens at the beginning when the cheese curds and that can be even floating in their own way. The cheese maker can introduce the penicillin at that point you won't see the bluing yet until election forms into a wheel. At that point a lot of times they will stab the outside of the wheel with the stainless steel rods to introduce oxygen and that's when the things happen and they won't press the Kurds to tightly together because they wanted to remain porous so the veining can gross through those Kurds.
And are cheesemakers still experimenting with molds?
So this limitation goes on and on for different types of flavors?
Yes, we see probably fortified to cheeses week.
In that blue cheese you just take it is probably listening-year-old. I mean up particular bump at the recipe.
What about aging cheese? Which is that to?
Will cheese is different every day of its life. And so a good example or good way to sort of explained that is when you go to the grocery store and you seek the chatters and there will be labeled mild medium sharp and extra sharp expecting cheese but different ages so they become hard cheeses will lose moisture so they will become more dense as they age. The textures going to change the Gouda that we brought today's a good example of that as well. Are going to get the little crystals.
Oh yes. [laughter] I'm still working on the blue. [laughter] All right, Rachel or certain kinds of cheese better or worse for your help because of the mold or microbes found in them?
Yes I think that is something we don't really understand at this point. We know them in cheeses there's billions microbes that are alive that we are consuming and many of them are closely related to things that you would find in yogurt and we have done some work showing that some of these microbes connection survived your gastrointestinal tract so we are very interested in finding out whether any of these microbes were eating on cheese could have impact on your help or may be directly for the microbes intercut. That it's not really something that we know this cheese has. These [ Indiscernible ] in a very specific in fact but there's many different-microbes. Every cheese has his own unique assortment of species.
And even though cheese and mold take small to create certain kinds of cheese, cheese can get moldy right?
Yes, yes so if you ever want a piece of cheese and left it in the refrigerator too long sometimes there will be molds in their environment.
And that's not aging used to start out.
Yes, you are not encouraging the right types of microbes on the cheese, guess.
Want to ask you both, we are talking behind cheese here. Or document gourmet cheeses with the cheese lots of American eat today's highly processed cheese food. What relation does that have to real cheese? The Mr. McCue, Robert.
Chattered genetically speaking the word chatter is not protected so it's a generic sort of cheese style that encompasses American cheese. A lot of American cheeses. What we label as American cheese anniversary store shelves is actually a chatter. It's just the highly processed on a really know all the ingredient would have to refund the packages to know exactly what's in it but it's basically a chatter style cheese so the relation is that it's just a lesser quality cheddar cheese for the most part or Swiss cheese again, very generic label and it is based off of a specific cheese that is from Switzerland but by no means does it represent Swiss cheese. There are hundreds of amazing varieties from Cicero and.
I that you know what is in the process Dr. Don [laughter]
Yes, it's definitely has a lot of science involved in it [laughter] A different type of science involved in making these processed cheeses but the cheeses that we are -- set in our lab and that Robert has in the shop, they are I guess considered gourmet but they are also the most traditional form of cheesemaking so there are cheeses that represent the style in ancient tradition that goes back thousands and thousands of years of people figuring out how to preserve and sort of enhanced the flavor and nutritional profile of this very important good source.
I understand that you have been contacted a great deal by shots who are interested in your work about microbes and how they changed the flavor of different foods here goes so our chefs getting more interested in the science of cheese and the science of food in general?
Obsolete, so I think from -- fermentation is a super hot topic in the food world right now and whether it cheese or kimchi or sauerkraut or pickles of any kind, I think it's just microbes are very diverse source of flavors and if you can learn how to harness them you can introduce all kinds of interesting flavors into your food and so it's just a really interesting kind of way of producing flavors and producing foods that are different than your normal set of ingredients that you are working with in terms of preparing food and adding spices you can sort of think of microbes as another set of ingredients in your pantry.
[laughter] I haven't yet but this is very interesting. No less Thursday in the journal current biology scientist reported that cheesemaking is actually changing the DNA of many molds. The molds are actually picking up sections of DNA from other species. Is that the kind of thing you will be researching your lab?
Yes, so this story is very interesting. It's an example where microbes are sharing genetic information that help them grow better in a specific environment and so the conditions that cheese has all these very specific requirements for microbes. So they have to be able to deal with the acidity of assault in the moisture and these microbes that they were setting word the Penicillium mold. They found they had picked up Jean said seem to allow them to grow better in the cheesemaking environment and by picking up these genes that means that they can now compete other molds that make the present so it's sort of a way to that microbes have figured out how to sort of better equipped to deal with the environment and this is something we see in cheese and in other foods but we also see pretty much everywhere that you find microbes in the environment I guess this is another way that we can say that by studying these microbial interactions in cheese we can learn something about how microbes are working in any moment.
So Robert, an addition to the blue cheese, what other kinds of cheeses are on this plate?
So going kind of clock live -- clock wise we have the [ Indiscernible ] and North Holland are, the home for Gouda is the Netherlands so specifically Holland and there's actually a little town called Gouda they pronounce it how death. I've been yelled at by saying Gouda before and that's a four-year cows milk version of that cheese. In the last cheese there are one string cheese called Willoughby and it's also cows milk is from a small artisan farmstead producer in Vermont who Rachel knows very well and when I say [ Indiscernible ] I am referring to a treatment that happens during aging process or the cheese maker or the [ Indiscernible ] is specifically that person who is aging the cheese gives it the grind kind of a saltwater bath which encourages a bacterial growth which is very, very good for the flavor.
Will open a similar essay is hosting this event is featuring Dr. Dotson. Do think there's a lack of cheese intelligence among the general public?
That is why we started the Me of cheese six years ago. That is her mission to educate the public and classes have been very popular and I think very educational so there still is a lack. There was a huge lack but I think we are working on that. We are making progress.
[laughter] The science of cheese program most current one will take place at any similar cheese Delmar this Wednesday advance tickets are required and as a reminder to our listeners if you have a scientific topic you would like us to explore or question you want answered contact us on Twitter at KP PS mid-eighties in the #psyche that is SCI- [ Indiscernible ] I must begin with brittle.and him [ Indiscernible ] thank you both very much.