Yeast: Bread, Booze, and Biology
For the past several years, the College of Arts and Sciences’ Food for Thought series has hosted many lifelong-learning events around the country, and in the …
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>> VANESSA CLOE: Good evening. On behalf of
the Indiana University College of Arts and
Sciences, I would like to thank you for joining
us tonight. I am Vanessa Cloe, and I serve
as the Director of Alumni Relations for the
Our Food for Thought livestreaming series
serves as an opportunity for our alumni and
friends to hear from faculty experts explore
topics of interest and stay connected with
IU and the College of Arts and Sciences during
this time when we are unable to easily connect
Before we begin tonight's program I am excited
to announce that the College is kicking off
a celebration of the enduring legacies of
our alumni over the next academic year. Our
'Celebrating Alumni Contributions 200 years
of impact' initiative Will highlight the contributions
our alumni have made to their professions
in their communities and to the university.
In addition to weekly social media alumni
spotlights we will host a special series of
events like tonight's discussion for our alumni
community in addition to marquee virtual events
with alumni dignitaries.
Please follow us on social media and watch
your inbox for an official announcement about
this special year of celebration.
With that, I am pleased to introduce tonight's
featured speaker, Professor Matt Bochman from
the Department of Molecular and Cellular Biochemistry.
Professor Bochman's research is supported
by the National Institutes of Health and focuses
on the maintenance of genomic integrity with
an emphasis on DNA helicases and other factors
involved in DNA replication, recombination,
and repair. As you may have guessed from the
topic of tonight's program, he also studies
the science of fermentation.
Following his presentation Professor Bochman
will be joined by two local IU alumni, Ed
Ryan and Bryan Smith, as we take your questions.
Ed is a chemistry alumnus and a co founder
and president and CEO of the parent company
of Big Woods Restaurant Group Quaff ON! Brewing
Co., and Hard Truth Hills Distilling Co. Bryan
is an IU alumnus and he is the Master Distiller
and a Co Owner of Hard Truth Hills Distilling
Company which is located in Nashville, Indiana.
You can submit your questions at any point
during this evening's discussion or during
the moderated Q&A. Simply click on the 'Questions'
tab located at the bottom of your screen.
Now, it's my pleasure to welcome Professor
>> PROFESSOR BOCHMAN: Okay. Hi, everybody.
Thanks, Vanessa for that kind introduction.
Let me get my presentation up here. So like
Vanessa mentioned, I am a scientist by training
but I decided tonight I was going to exercise
one of the five pillars of the college of
arts and sciences and act creatively and instead
of talking about the science of fermentation,
I'm going to give you a history lesson. We're
going to talk a little bit about bread, booze
and biology and it's all going to center around
This is the organism we're going to talk about.
Let me switch my cursor over to a laser pointer.
This is the main organism used by my lab and
many labs around the world. The you break
down the Latin in the name, it tells you everything
you need to know about this word. Sugar, fungus
and cerevisiae is the lateen word for beer.
This is a fungus that eats sugar and makes
beer. We use it for a lot of things and bakers
use the exact same thing to make bread. The
distillers are using saccharomyces cerevisiae
to make the preingredients for hard liquor.
This is a biotechnological and workhorse organism.
People, especially in the sciences are interested
in yeast because of the simplest eukaryotes.
If you remember biology class, a eukaryote
is a type of organism with a single cell.
We are learning something about more complex
organisms such as ourself.
Yeast are fungi and it's not just saccharomyces
cerevisiae that's the only yeast. There are
150,000 species of yeast predicted. They're
single celled so they're microbial but they're
ten times larger than bacteria which you can
see in this micrograph right here. The rods
are bacteria and these are the budding yeasts.
This is a workhorse organism. We're going
to get to this in the end about how many,
many biological breakthroughs were discovered.
In fermentation, a sugar fungus that makes
beer. They're looking for sugar in the environment,
it's transported in the cell. Simple metabolism
happens if you remember glycolysis. Their
waste products are Ethanol and carbon dioxide
which is what we're interested in if you make
beer or liquor, wine. We're after what the
cells don't want. It's not all beer. Bread
is a fermented product, bread, cheese, wine,
beer. The list goes on and on. They're all
fermented products. Not fermented by saccharomyces
cerevisiae. But many in the vegetable realm
are fermented by a host of different products.
Sugar goes in and Ethanol, carbon dioxide,
pickles, different acids come out.
I think Vanessa has a poll she can run. If
everyone can click on their favorite fermented
product we can see where everybody stands
at the end of the show.
>> VANESSA CLOE: Could you please turn on
>> PROFESSOR BOCHMAN: Yes, ma'am. Is that
>> VANESSA CLOE: Looks great. Thank you.
>> PROFESSOR BOCHMAN: Okay. We'll let this
poll run for the end for a few seconds.
Looks like beer is the winner. Probably what
I'd vote too. All right. Beer is the winner.
There we go. Okay.
So it's important to know that fermentation
predates us. This was the earliest form of
energy production on earth. Microbes whether
they were yeast or protobacteria, they ate
sugars or some type of carbohydrates and excreted
Ethanol or some kind of alcohol. They did
this because these are waste products and
they make the environment toxic. If you want
to kill the neighbors so you can eat all of
the local food, this is the way to do it.
Yeast cells are naturally toll lent to Ethanol
and the acidification of the environment by
carbon dioxide. They can stand the stress
but maybe the neighbors can't. That's why
fermentation took off as a met Pollock process.
And it turns out that alcohol and evolution
are intertwined. Fruit is probably the most
abundant source of simple sugar out there
in nature. Sugar is energy. Probably unsurprisingly,
fruit readily ferments on trees and vines
and then it drops on the ground and there
are microbes always looking for the sugar.
And animals are naturally attracted to the
scent of fermentation because our brain tells
us that means food is nearby. Fruit flies
buzz around rotting fruit because the fruit
has started to ferment. Lots of examples of
higher mammals that get drunk eating fermented
fruit. You can imagine a stampede of drunken
elephants ruining a town or a forest. It happens
all of the time. Monkeys falling out of the
trees because they eat too much fermented
fruit. Like a frat party.
Where do humans fit into this. There's symbiosis
between people and Ethanol. Humans as a group
make a ton of Ethanol every year. On the order
of 40 gallons of beer, 7 billion gallons of
wine and 500 million gallons of distilled
liquor. This volume isn't 100% Ethanol, but
if you boil it down, it's over 2 billion gallons
of pure Ethanol that we're using yeast to
make every year and then another 8 billion
gallons for fuel, chemicals and pharmaceutical
industries, et cetera. These are old numbers.
These are from 2003 and my guess is that they're
only going up and up. This is an underestimate
for how much yeast is utilized by humanity.
So how and why did this happen. That's what
we're going to get into. Basically alcoholic
beverages are clean water. If you think about
beer, if you've ever home brewed or you know
somebody that makes beer, there's a boiling
process that's involved. You're killing all
of the microbes that are naturally abundant
in that water, things that could give you
dysentery. People realized if they drink alcoholic
beverages, they tend to be healthier than
people who drank water. The same is true for
coffee. You can boil the water for coffee.
Fermentation adds nutritional content to whatever
is fermented. It's better for you to eat and
drink fermented products. There are health
benefits for moderate alcohol consumption.
It's good for your kidneys to be flushed out
with the alcohol. The hops in beer are anticancer
agents. There are lots of benefits to moderate,
you know, drink responsibly.
And it wasn't one or two places that sort
of developed fermentation. Ancient mankind
utilized it all over the world. You can say
it was invented many, many times. Why is that.
We have soy sauce being invented somewhere
200 to 400AD in china, yogurt, your favorite
fermented milk product in Asia, pickles in
India. Why do this so often. Again, it's not
that it just makes it tastes better and it's
more nutritional. It's preservative. Alcohol
kills things. Acid kills them from fermentation.
The fruit is not going to rot.
This is the best way to keep cucumbers and
other vegetables edible throughout the year,
by pickling them.
As a scientist I'm interested in the history
of science. What I found is that the history
of fermentation mirrors the history of not
just modern science but western science as
we think about it. A lot of what I'm going
to tell you tonight comes from this book "proof"
by Adam Rogers. It's a short read. A great
book if you're looking for a Christmas or
birthday present for somebody. I recommend
this. It's not super nerdy. The average person
can approach it. But if you're an alcohol
aficionado, it's worth a read.
I'm going to steal a phrase from Stephen hawking,
give you a brief history of time. 14 billion
years ago the big bang happened. 5 billion
years ago the earth formed, squeezed out the
moon. Three and a half to four billion years
ago, not long after the earth formed life
began. That was the beginning of fermentation.
And then for a long time nothing interesting
happened. Yeah, there were some dinosaurs
in there, if that's your thing but they died
off. It wasn't until 200 house years ago that
humans evolved. And it took a long, long time
for them to control fermentation. So it's
easy to pick up fermented fruit from the ground.
It's harder to control it. That happened about
10,000 years ago as far as we can tell somewhere
in china. Distillation came along 2,000 years
ago. And then it was only in 1882 that we
realized it was yeast responsible for this
fermentation the whole time. And that sort
of struck me as odd. How can we control fermentation,
how can we get to this part where we can distill
things and we don't know how fermentation
works, the organism that's doing the job.
This goes all the way back to Aristotle now.
Aristotle is widely recorded at least in the
western world as the first scientist. He studied
physics, biology, geology. And he actually
produced the earliest surviving written work
on fermentation. You can read his treatise
on fermentation today.
This was 2500 years ago and Aristotle wondered
why sugary liquid, something like grape juice
became alcoholic. And his hypothesis was the
existence of the vis vita, the vital force
that animated all living things toward goal.
Grape juice wanted to turn into wine due to
this vis vita and when wine got old and turned
into vinegar, this was the passing of the
vis vita. This was akin to death.
And he also made observations that when sugary
liquid like grape juice ferments, you get
a haze formation. This is nonfermenting sugar
water. And this is fermenting sugar water.
Eventually the haze settles to the bottom.
And if you took some of that sediment and
put it in your next fermentation, it helped
out. The fermentation took off faster and
the product was better at the end.
That was basically the extend of what Aristotle
knew. He knew fermentation happened. He knew
haze formed. He knew sediment happened but
he didn't know what the sediment was. That's
been the question for hundreds of years.
And eventually that sediment was called yeast
not because we knew what it was, because we
knew what it did.
In French and German, the words come from
the word lift. Yeast makes the bread rise.
The English wordiest comes from the Dutch
word gist which comes from a Greek word of
boiling. If you've seen fermenting wind or
beer, you are carbon dioxide bubbling to the
surface. That's where the word yeast comes
Here's your Jeep parody fact of the day. Getting
to the gist of something mean boiling it down
into simple terms.
That's where stealing the phrase of getting
the gist of something comes from.
We know the sediment is important. We've got
a word for it, a different word, whatever
Lang want you prefer. How do we figure out
what the sediment actually is.
This is where the scientists come in. So biologists
at this point had developed the microscope.
They were looking at fermenting products.
They sound round things and hypothesized perhaps
they're the agents of fermentation. Theodore
Schwann came up with cell theory which states
that all living things are made of cells.
You look at a bit of human tissues or plant
tissues, there are small sub parts and they're
called cells. So he hypothesized that the
microbes were the actual agents of fermentation.
That's a biologist. The chemists disagreed.
The chemists thought that fermentation was
a chemical process. You didn't need biology
involved at all and it just happened when
fruit juice was left alone, or sugar water,
something with sugar in it. So they said well,
okay, sure. There's yeast in beer. But eventually
the yeast dies and then it decomposed, and
that decomposition product releases some sort
of energy. That energy smashes into carbohydrates
releasing carbon, hydrogen and oxygen and
they spontaneously form into another carbohydrate
known as alcohol.
So this isn't that far from Aristotle's hypothesis
of vis vita, right, this force driving things
towards that they want to be. But this was
state of the art in the 1800s in organic chemistry.
I'm an academic so I can poke fun at the fields.
It turns out that academics now and then can
be mean and childish. These chemists actually
satirized Schwann's work. Here's a quote.
In short, the cells eat sugar, eliminate alcohol
from the intestinal tract and carbon dioxide
from the urinary organs. Who would think but
a chemist the liquid comes out of the back
and the gas comes out of the front. They're
poking fun at Schwann. They got Lewis Pasteur
at the time.
It wasn't until a chemist and a biologist
got together that they solved the problem.
The first great science collaboration. This
was between the Buchner brothers in 1897.
They grew yeast, fractionated the yeast and
fermented it into Ethanol and carbon dioxide.
And they named that extract zymase. The root
word for enzymes. This is where my current
field of study was born. And it was so important
that they won the 1907 Nobel Prize in chemistry
for basically creating their own field. And
this wasn't the only Nobel Prize given to
yeast research. Many of the recent Nobel Prizes
have gone to projects that really started
and laid the groundwork using yeast as a model
system. So science that has bearing on chemotherapy,
Alzheimer's, cystic fibrosis, cancer and aging,
the basic processes that really underpin all
of these devastating human diseases.
And that's sort of where I come in at IU.
So my lab also uses yeast as a tool and we
use it to ask and answer biological questions
in the lab. So I'm going to show you a slide
that I use to try to recruit grad students.
This is busy. I'm going to touch on it. We've
got projects in the lab on a particular type
of DNA repair for chemotherapy resistance.
We're using yeast to learn about how different
enzymes are regulated in the cell. We're learning
about premature aging diseases and the natural
aging of cells, as well as cancer. And again,
lots of processes that underpin all of these
things. Really the basic biology of the cell,
we're trying to learn about. We use lots of
experimental techniques, but yeast is where
we make our discoveries.
We've put it to work locally to help out businesses.
We've worked with different breweries and
distilleries to help out with some process
innovation or provide yeast for them to do
experiments on their own. Upland has come
out with lots of beers fermented with our
yeast strain, some of which we found locally
here in Bloomington. And it's been sort of
so successful that we've partnered up with
lots of breweries and distilleries all over
the country now. So I know lots of you aren't
local that have come into the Zoom. Maybe
you see some local flare here for you. We've
got the Maui brewing company, rare barrel
on the west coast, doctor's head in Delaware.
The list goes on and on.
So that's enough about me. I want to invite
Ed and Bryan to jump in here and we can go
through some questions. So we'll wait until
those guys sign on.
Again, I appreciate everybody taking the time
to join us tonight for this. If you don't
know Vanessa, her office hosts really good
live sessions of these as well. When the pandemic
relaxes and they can resume, I recommend signing
up if you can. There are Ed and Bryan. How
is it going, guys.
>> BRYAN SMITH: How's it going?
>> PROFESSOR BOCHMAN: Cheers.
>> ED RYAN: Nice job, Matt. That was really
>> PROFESSOR BOCHMAN: Thank you. So we've
got a few down in the chat box here.
Somebody asked in Aristotle came up with a
concept of a sour mash process. So Bryan,
you know what sour mashing is. Why don't you
lay that on us so everybody knows what we're
>> BRYAN SMITH: Sure. So sour mash in the
world of whiskey, probably a lot of people
are familiar with seeing that on a bottle
of Tennessee whiskey or some bourbon. Sour
mashing speak to a little bit about what you
talked about earlier, Matt, where you take
some of the spent mash from an earlier fermentation
that goes through the distillation process
and you add that back into the new cook. So
you're adding that in with the fresh yeast
and the fresh grains and water. And really,
from what I understand in the whiskey world,
the fermentation vessels that they were using
and the processes they had in place were not
very sanitary. And they were also — they
were also doing large quantities. So they
wanted to make sure that they didn't lose
the fermentation. The sour mash helped to
set the PH low tore help prevent bacterial
contamination so the yeast could have a little
So what we do at hard truth, we're a sweet
mash distillery, just based on palette and
flavor. All of the research that we did on
the way in on this, for the flavor profile
we want for our whiskey, to create a flavorful
whiskey, we incorporate a sweet mash technique,
start with fresh yeast, grains, fresh water
with every single cook.
>> PROFESSOR BOCHMAN: Aristotle didn't come
up with the concept, but he was the first
one to document it. People have been making
wine and knew that if you threw some of the
sediment in the next batch it would work better
and that's exactly the same thing with sour
mashing. [ Inaudible ] are starting to use
this as a way to make shower beer. That's
one of the projects that we helped upland
with, the best way to carbonate their sour
beer. And it turns out if you preadapt the
yeast and basically sour beer, sour mashing
it essentially, it takes off a lot better.
So it seems to be sort of fermentation wide
that sour mashing is useful.
All right. Another question here about how
humans have changed yeast since we've started
using it and have we selected traits through
selective breeding. So 100% yes. Saccharomyces
cerevisiae is the species that's used to make
beer and wine and, you know, the beginning
products for whiskey and so many other things.
But there are different strains of saccharomyces
cerevisiae. So cerevisiae is the species.
You can think of strains as sub species or
ethnicities on something like that. And if
you take a wine yeast, you basically can't
make beer out of it because it can't ferment
beer sugars. It's been selected to fermentation
M. grape sugars or fruit sugars. So people
have sequenced yeast genomes from everywhere,
soy sauce, beer, from sake, whatever you like.
And there's a tremendous amount of diversity.
And you can actually sort of build the family
tree of these yeasts and you can see different
domestication events that have happened. There's
a big one in Germany, a bigger mantra addition.
There's a big one in England because there's
a big British tradition. A big one in Asia
where the sake and soy strains came from.
Not only are we using yeast for our own purposes,
but yeah, we've certainly domesticated them
in the ways that we like.
I don't know if the guys at hard truth use
a variety of strains for these purposes, if
Ed or Bryan want to speak to that.
>> BRYAN SMITH: Sure, yeah. I can speak to
the distillery. Those yeast strains that you're
talking about being isolated and chosen for
different flavors, we work with a yeast company
that was able to give us examples of distillate
distilled by different yeast strains. We were
able to do some trials on the front end of
our whiskey production. It's really amazing
that that one, you know, that one yeast — there
could be a different variety of flavors that
you could get from the different isolated
strains. We've got one strain that gives me
— it ferments very hard on the front end
and I get a lot of bright tropical almost
like mango notes in the final distillate.
Others are more mellow and you get gentle
subtle flavors from those. And I just find
it endlessly fascinating, you know, that each
distillery has its own thumbprint of the wild
yeast that exists in the distillery and the
area around and also the beneficial bacteria
that help to create unique flavor from distillery
>> PROFESSOR BOCHMAN: Definitely. As far as
beer goes, beer that's not heavily hopped,
the yeast can be 50% or more of the final
flavor. So your choice of yeast has a huge
impact on the type of beer. You can start
out with the same base beer, split it into
five different fermenters and add five different
yeasts and get five completely different products
at the end from the sugar water. Anybody who
enjoys the German one with the flavor and
clove to it, that's coming from the yeast.
There's no fruit or spice added. Those are
yeast metabolic byproducts.
Question about does our yeast go into scholars
in bakery bread. No, not yet. But there's
no reason it couldn't. It's baker's yeast.
Brewer's yeast. It's all the same thing. If
you make a sour dough starter at home, whatever
yeast is resident on your sack of flour, that's
what takes off. We've talked a little bit
about Oliver winery. But for some reason the
wine industry has shied away. They sort of
have the process locked in. I don't know.
Let's see what else have we got here. We've
got some Q and A questions not just in the
webinar chat as well. Let's go to one of those.
Can you speak to auto brewery syndrome. So
auto brewery syndrome is an infection with
saccharomyces cerevisiae or another yeast
that ferments carbs and alcohol. You and I
and everybody naturally have yeast on your
skin and in your digestive system. But when
the balance goes off the yeast takes over.
And auto brewery syndrome is what it says
it is. The
ways to treat it are to try to kill the yeast.
It's hard to treat yeast as opposed to bacteria
because yeast cells are a lot like human cells.
People have used fecal transplants instead
to repopulate their gut microbe biome.
Let's take another one here. Is the yeast
I use in bread making the same that you use
in beer? It's the same species, maybe not
the same strain but there's no reason you
couldn't go to the upland brewery company
and get a little yeast sediment and make bread
out of it. No reason they can't make beer
out of your bread yeast. It may not taste
the same, but it will have the alcohol in
Can I discuss wild yeast versus bacterial
flavor profiles in beer. So this sort of gets
to what Bryan was saying about, you know,
there's a fingerprint of different local microflora
no matter where you are. If you go to Jamaica
and you have a Jamaican rum, the climate is
hot, it's humid, there's organisms that thrive
there that wouldn't thrive in Bloomington
or Nashville. We can never recreate the Jamaican
rum because we don't have the organisms, but
we can propagate them and much them in a batch
of rum, I guess.
My lab has found probably 400 wild yeasts
now and we've brewed with all of them. We've
tasted all of those beers. And the overarching
flavor component is nothing. They make alcohol.
They make carbon dioxide and that's it. I'm
convinced that lots of craft beer is contaminated
with wild yeast because there is no fingerprint.
Bacteria is for pernicious. There's lots of
bacteria that that can get sulfurous, make
rotting come bounds. There are bacteria that
can make things literally slimy, call ropiness.
You can pour beer and get a runner of slime.
There are things that can make biofilms. You
get a film on top of the beer. So the flavor
landscape maybe of bacteria is much wider
than yeast but you can get some of the same
things. There are bacteria that sour beer.
We've found yeast that sour beer. There's
bacteria that can make things fruity. We've
found yeast that can make things fruity. Lots
going on there.
So let's go through some more of these questions.
And Ed and Bryan, if you see any of these
and you want to dive in or shoot one towards
me, please do.
>> BRYAN SMITH: Looks like we had a questions
about open top versus closed top fermentation.
So I can speak to that. At our distillery
we have a classic bourbon style fermentation
vessel. They're completely open top. Whenever
our brewery friends come over to visit, it
absolutely blows their mind, makes them extremely
nervous. They don't seem to like it very well
because, you know, in the beer process versus
distillery process, in distilling we're running
it through a still and we're going to separate
it out, keep the Ethanol and leave the rest
of the stuff behind. With beer it all has
to be controlled and contained in order to
reduce your risk of different cross contamination.
But one thing that they've done in the distilling
industry, they've been able to isolate strains
of yeast that are so incredibly powerful and
dominate that, you know, as long as they're
applied correctly into the mash at the right
time, the right temperature and the right
volume, there's really — it's almost impossible
for them to be outcompeted. So while there
I'm sure are some yeast in bacteria that exists
in that mash while it's fermenting, the primary
yeast strain is absolutely, is absolutely
taking most of the sugar from the solution
and turning it into Ethanol. And that speaks
back to what we were talking about with the
different strains creating different flavors.
But it's really also, you know, part of the
experience. So when you come on a tour, you
know, you're looking over this big vat of,
you know, of fermenting foaming mash and people
like to stick their finger in it and you know,
lose glasses in it, all kinds of fun stuff.
It's definitely part of the show as well as
being functional. But it would work with closed
top as well. We would just — a lot of closed
top fermentation distillery have to have a
way to vent out the CO2. That would take some
additional piping. So with ours it just goes
out in the atmosphere and vents its way out.
>> PROFESSOR BOCHMAN: We've got a fun question
here about what beer shows up for us on a
special night. What do you like to drink on
a night when you really want a good beer.
Ed, why don't you start off and we'll each
take a turn. You're unmuted now. Can you hear
>> ED RYAN: Yeah, hey, Matt. I love that question.
>> PROFESSOR BOCHMAN: What beer shows up for
you on a special night?
>> ED RYAN: As we're moving into fall beer
it's — this is one of our favorite times
of the year because you have the traditional
October fest beers coming out. I really like
the Oktoberfest. We have one that we have
on tap now. My favorite beer is the pumpkin
>> PROFESSOR BOCHMAN: Oh, all right.
>> ED RYAN: We call it put a fork in it and
it really is a fantastic pumpkin beer. I've
challenged people for five years now to bring
me a pumpkin beer that tastes better than
our pumpkin beer. No one has done it yet.
>> PROFESSOR BOCHMAN: It is a good one. I
can vouch for that. What about you, Bryan?
What drink on a special night? You're muted.
>> BRYAN SMITH: There we go. So I like most
beers. But if I'm — just today I had some
samples at lunch. I had a guest in and one
of my favorites is java the red. It's a red
ale infused with coffee. Not typical. And
most beers that are infused with coffee tend
to be heavier bodied beers. And I love that
it's a nice clean red ale. I also love Mexican
beers in general, especially when it's hot
>> PROFESSOR BOCHMAN: I'm an equal opportunity
drinker. I don't have a favorite style necessarily.
I do like to drink local, as cliche as that
may be. But when I travel, you know, I look
for the local breweries there. I'm not always
looking for an upland or a taxman beer. I
want to try what's local there. But I tend
to go for the palette wreckers, a double IPA
or imperial stouts or a sour beer. Big fan
of upland source. I like the QTFO when I'm
in the mood for hops. Quaff On. There's a
brewery in Virginia called hardy wood and
their barrel aging gauge is just on point.
Depends on the kind of night it is, depends
on the temperature. But those are sort of
my go toes on a special evening.
And thankfully my wife is also a beer drinker.
So we can crack open a big bottle and split
We've got a couple of questions that are along
the same lines of how is yeast — commercial
yeast prepared. So something like yeast for
baking, you know, you basically start out
with a starter culture and you grow it up,
propagate it ten steps up. You're growing
it in sugar water. You need sugar, a nitrogen
source so the yeast can make proteins. A buffering
agent, things like that. Honestly, it's pretty
simple. You can grow yeast in just sugar water
if you're careful.
And you can centrifuge that out or let it
settle out, decant the water and basically
dry the yeast cake. There are various ways
you can dry it. People run hot sterile air
over the top of it and dry it that way. Some
people extrude it like noodles when it's really
dehydrated, you can sort of make it like play
dough and dry it that way. For things like
baking you don't honestly need to be sterile.
When you make bread it's not rising that long
so there's yeast and bacteria there.
But for things like sweet mashing and craft
brewing, you want a good culture that's nothing
but that yeast. There's no other yeast. There's
no bacteria in there. It's actually quite,
quite a biological or maybe a microbiological
fete to propagate large volumes of yeast in
sanitary conditions and not contaminate it
from step one to step 10, you know, in the
factory and get it to the brewery. And lots
of these are live cultures. They're not dried
down. They're shipped liquid. You have to
have a sterile chain the whole way through.
And when you make a large batch of beer, you
know, a 30 barrel batch, you're inoculating
it with trillions of yeast cells. And even,
you know, a single bacterial cell or a single
wild yeast cell probably won't do anything
to that batch. But if the brewer reuses the
east, it can affect the down batches. Everybody
needs to be as sterile as possible.
It's as simple as adding yeast to sugar water
and you get yeast babies.
So yeah, got a couple of people giving the
stick a fork in it the thumbs up. That's a
local favorite to. Good for Quaff On.
Oh, okay. Here I guess this is one for Quaff
On. Do your beers contain lactose.
>> ED RYAN: I can answer that question. No,
they don't. You probably know that better
than I do, Matt. That's kind of the way to
cheat to make source. And we don't make source
and we don't add lactose to our beers. Lawrence
has a good question here. He's asking what's
in the barrels behind me. And I might add
that everybody has good questions. It's almost
like we're in the middle of a pandemic, right
and we're looking for something fun to talk
And I believe we have someone on — listening
to this Zoom event in Japan. So I'd like to
point out that our friend won the 104th running
of the Indianapolis 500. And we made a beer
called Sada101 with him when he won the 101st
running. So we're pretty excited about the
fact that he won the 104 running also and
now we're going to put the pressure on Bryan
to make a really cool bourbon that has some
scotch undertones because we know that the
Japanese love those scotches.
But anyway, back to what's in the barrels
behind me, there's two things. One is it's
a 15 year old Tennessee whiskey that we'll
be putting in barrels with our name on them
just because it's such a wonderful product.
They'll be called Scoonovers. He was the first
seller of brown town. We're going to honor
him with that bourbon.
The other thing is our barrel aged busted
knuckle, which is a really cool beer. And
we actually amp up the ABb of busted knuckle
to about 10% and put that in the barrels.
I should also mention that we have an imperial
pumpkin beer too on tap at some of our restaurants
right now that's also 10%. And I tasted some
of that tonight. It's Quaff worthy.
>> PROFESSOR BOCHMAN: My wife and I go to
the big woods pizza restaurant for our anniversary.
That's our big night out away from the kids.
Sounds like we might need to get there sooner
and try the imperial pumpkin.
>> Get your Quaff on.
>> PROFESSOR BOCHMAN: There was another question
about Belgium brewing. This is open fermentation
beers. So the Belgium tradition is sort of
the funkier beer. It's sour — although not
all Belgium beers are sour. Open fermentation
is a thing. And the story that they tell everybody
is that, you know, the breeze from the local
orchards comes in and it brings all of these
microbes from the fruit trees and the climate
is right and it inoculates the beer in an
open fermenter and that's how you get the
wonderful flavors. You can only make a beer
like that in Belgium pap people believed that
for the longest time. Didn't believe you can
make a sour beer in America. But now everybody
makes a sour beer.
And it turns out if you go to Belgium — I
haven't. This is hearsay now. It's not really
the breeze that's doing it. You know, if you've
got a brewery and you leave the window open,
it's the hot air from the — the cooling mash
that's going out. Not the nice breeze coming
in. There's an efflux of brewery air. What
it is, they've got the wooden rafters. The
brewery is inoculated with all of these microbes.
The steam rises, condenses on the ceiling,
grabs the microbes and drops into the beer.
It's gnarly to say that. That's how it's inoculated.
They will literally build a new roof over
the top of the old one instead of taking out
the old one because they want the culture
growing in the beams.
Now that's not to say that you can't take
a beer and put it outside and really have
mother nature inoculate it. That's called
a cool ship as a technique. And upland does
that. Many breweries do that. I've heard of
people where they put a flat container in
a truck and they can drive it around to wherever
they want and inoculate it in a national forest
or inoculate it on campus. H.
You can make fermentation work that way. It's
hard to get it to turn out well at the end.
Lots of beer gets dumped because it tastes
like tomatoes or something at the end of it.
But the Belgians, as a brewing tradition,
really inspired so much of American craft
beer just because they do have these techniques
that you don't find elsewhere. And the beers
are phenomenal. If you get the chance to drink
a proper Belgium sour, jump on it. It's not
to be passed up.
Okay. I've got a question about home brewing
here. So I do home brewing. Not as much as
I did before my kids were born because my
free time disappeared every time I had a kid.
But I do try to home brew a little bit. I'll
make Kombucha, I make beer, cider.
As far as tips for getting into home brewing,
the hardest thing is just the first brew.
It's just trying, you know. Get in there,
try to make some beer. You're going to make
mistakes. Everybody does. If the first beer
turns out great, doesn't mean the second beer
will. You're better off if you brew with a
buddy. Maybe somebody who has done it before.
Or maybe somebody new to make sure you're
cleaning it well. Cleanliness is next to Godliness.
If you're cleaning everything. All of the
surfaces. If you stir the mash with a spoon.
Clean the spoon. Clean your fermenters. Don't
give the bacteria a chance. That's my best
advice, is to keep it clean.
>> BRYAN SMITH: Matt, there's a question about
coffee. Someone is asking you to talk about
coffee in fermentation which I'm interested
many. I don't know a whole lot about that.
>> PROFESSOR BOCHMAN: Yeah. So coffee and
chocolate and lots of things like that. It's
literally the bean that's fermented. You know,
some are fermented — I don't know how you
call it, in husk. Whenever the truth that
surrounds the bean. Some are fermenting the
beans themselves, whether it's a cocoa bean
or coffee bean. These are solid state fermentations.
You're not putting this in sugar water and
letting it ferment. You have a moist pile
of biological matter whether it's the beans
or the fruit and the beans. And that fermentation
process ends up being really important because
it can break down products that would otherwise,
you know, be too bitter or too tannic or too
off-putting in the final product and they
could generate flavor and aroma products that
you want in the final product.
So for something solid like a bean, I don't
know how much nutritional content that may
add. But if you break down, you know, complex
carbs into more simple things that your body
can use, there some nutritional benefit there.
From what I understand, it's mostly the sensory
aspects is where fermentation really comes
>> BRYAN SMITH: Saw a question too about making
beer from stale bread. I don't know anything
about that, but I will tell you just an interesting
article I read about. There was a bakery in
New York that was taking leftover pastries
and bagels and bread, anything that was going
to get thrown away and they were actually
grinding it up and making whiskey with it,
which I thought was really fascinating. It
just shows you that a lot of whiskey innovation
and whiskey creation is always born out of,
out of trying to, you know, make something
out of nothing. And use everything that you
can to make some alcohol from. So I love that.
>> PROFESSOR BOCHMAN: Yeah. Any place that
you find carbohydrates whether it's steal
bread or fruit, you can ferment. There's a
Russian beverage called Kvass. And it starts
with rye bread. A weak sort of vodka where
the fermentable sugars, the carbs come from
rye bread. I don't know of anybody locally
that's using bread. They haven't partnered
up with a bakery to use their castoffs or
anything like that.
I'm from Pittsburgh originally and there is
a brewery, I think it's the east end brewery,
that has done this. They've taken, you know,
day old, two day old bread from a local bakery.
They make a beer with it. I can't remember
what it's called offhand. But I'm sure they
supplement it with malted Barley. That's not
the only carb in it. You need a certain percentage
Barley to be considered a beer for tax purposes.
To keep the government happy I'm sure there's
Barley in it. You can certainly repurpose
stale bread. Instead of feeding it to the
ducks, feed it to your fermenter.
All right. What have we missed?
>> ED RYAN: We had a question, Matt, about
does beer contain sulfates which it does not.
Sulfur dioxide is added to wine but is not
used in the brewing process.
>> PROFESSOR BOCHMAN: That's difference between
the wine strains and beer strains. The wine
strains are more resistant to sulfur compounds.
When you make wine there's no boiling step,
no kill step so sulfur dioxide is used to
kill microbes that they don't want, bacteria
and wild yeast where saccharomyces cerevisiae
with stand that. But beer is boiled and it
contains hops and hops aren't only delicious
and smell nice, they're also a natural preservative.
So you don't need to use sulfur dioxide for
>> BRYAN SMITH: Mark added a question calling
me out about using stale bread to make whiskey.
How can you call it whiskey? Which I love.
You should work for the TBB. There's governmental
agencies that monitor what you can put on
a label and call it whiskey. Mark is absolutely
correct. There are certain rules about, you
know, what can be added. So I would say if
it were just bread that were made from, you
know, grain, east and water and baked and
then ground up, I think that would still qualify
as whiskey by the law. But yeah, if you're
using like some leftover sugar pastries or
something like that, you'd have to have a
fight with the TTB on whether you could call
it whiskey or not.
>> PROFESSOR BOCHMAN: I think we are getting
the land the plane motion here. So that's
probably the last question. Vanessa, I don't
know if there's anything you want to say before
we wrap it up.
Thanks, Ed and Bryan. This was great. I appreciate
it. And everybody else for asking questions.
>> VANESSA CLOE: Thank you so much, Matt.
This is absolutely fantastic. Additionally
I would like to also thank Ed and Bryan for
their expertise as well. We're grateful to
Finally I should acknowledge that events like
that would not be possible without the support
of donors who understand the education. If
you would like to support the faculty, students
and programs of the college, please consider
making a contribution to the arts and sciences
priority fund at the IU foundation.
Until next time, please take care and I hope
you can join us for our next event, which
is going to be next week, on Wednesday, September
2nd. Our 162,020th with Professor Clark.
>> Stay safe, everybody.
>> Go Hoosiers.