Joanne Chang: The Science of Sugar

October 10, 2019 0 By Peter Engel


MICHAEL BRENNER: Welcome to the
second lecture in our series on Science and Cooking, and we’re
delighted today to have Joanne Chang. This week the topic
is phase transitions. Now phase transitions is
what happens, like when you boil water– you know
that when you heat water, it goes from being a normal
temperature, to being at some point the liquid transforms
to a gas– and there are lots of phase transitions in cooking. I mean, in fact, arguably
cooking is really the control of phase transitions. And it turns out that one of the
most useful phase transitions, and really one of the most interesting
for cooking, happens with sugar water. Which is going to play, I think, a
prominent role in tonight’s lecture. And I mean the thing about sugar water–
actually is anyone drinking Coca Cola? Does anyone have a Coca Cola? You have a Coca Cola? No one will admit it? So I mean, OK, so let
me ask you a question. In fact, maybe in fact I’m
not going to use my slides, maybe I’m going to talk about
phase transitions instead. So I should have brought this demo. So does anybody know if we
took– is that a beaker of water? JOANNE CHANG: This is ice. MICHAEL BRENNER: That’s ice. So if we took water, that’s
about how much water is that? That’s about– that’s 5
and 1/2 cups of water. Does anybody know how much sugar we can
dissolve in 5 and 1/2 cups of water? That is for example, suppose
we had another beaker which is filled with sugar up
to this level, do you think if we mixed it in the
water it would dissolve? Who votes yes? Who votes no? OK, so most of you didn’t vote. Did you notice that? They didn’t vote. So let’s try it again, you’re not
allowed to get away with that. So this is a straightforward question,
you can go home and verify it. If we had 5 and 1/2 cups
of sugar, and we poured it in 5 and 1/2 cups of water, who
votes that it would dissolve? Who votes that it wouldn’t dissolve? OK, so what if we have
5 and 1/2 cups of salt? Instead of sugar, salt. It’s a cooking material right? You can use salt? Who thinks that the salt would dissolve? Who thinks that the
salt would not dissolve? OK, so what if we had 10 cups of sugar? So that’s 5 and 1/2 cups of water. Suppose I had 10 cups of sugar? Who thinks it would dissolve? Who thinks it wouldn’t dissolve? OK, you’re getting better voting. So the answer is that 10
cups of sugar would dissolve. So the solubility– So you can
dissolve twice the weight of sugar in the equivalent weight of
water at room temperature. Now Joanne’s going to be doing a lot of
boiling, are you going to be boiling? JOANNE CHANG: I am, yeah. MICHAEL BRENNER: So
when you boil, suppose you have water at 100 degrees
Celsius, boiling point. How much sugar can you dissolve then? Does anybody know? Maybe I’ll ask it this way. So let’s say we had 11– so
I’m leading you to the answer– but we said 11 cups. So what about 15 cups? Can you, at boiling water, 15 cups? 20 cups? Who votes 15? Who says yes? 20? Who says yes? So it turns out four times, it’s a
factor of 4 at 100 degrees Celsius. It’s also the case– and maybe this is
a better intro than what I’ve prepared, come to think of it,
cause this might even be relevant for what
you’re going to talk about, that’s unusual right– so it’s
also the case that– I don’t know if you knew this, but– the
boiling point of sugar water mixtures increases with temperature. So if you actually were to put four
cups of sugar into a cup of water at 100 degrees Celsius, the
water wouldn’t be boiling, the mixture wouldn’t be boiling,
the boiling point actually goes up. And I think what you’re going to
see when Joanne gives this lecture, and this is dangerous
for me to see, cause I have absolutely no idea
what you’re going to say, but anyway this will
be– except that she’s going to talk about sugar– is that
you have to control temperature very carefully. Because what happens, of course,
is that if you just dump heat in it then the thing starts to boil, the
gas comes off, and that of course means that the sugar fraction increases. Which makes the boiling
point increase more, which makes the sugar
fraction increase even more, and there’s a runaway
phenomenon in this. Which is the reason, how
many of you make candy? How many of you don’t make candy? Okay good, just checking. Which is the reason that you
have to buy candy thermometers. Joanne I don’t think
needs a candy thermometer. So she’ll explain to you how she
gets away with this presumably. Or she doesn’t, ask her. So with no further ado,
let me introduce Joanne. So I actually– it always
makes me very happy to introduce Joanne for a
number of different reasons, but one of them– which for those of you
have come here before, you’ve heard me say this but I’ll just say it
again– is that Joanne was a Harvard undergraduate, and she
was an applied math major. And I, as it happens, run the
applied math major at Harvard. And I’ve never understood why I was
involved in the science of cooking. And Joanne though, well
she was in applied math, and she actually knows what she’s doing. And so it’s sort of
somehow made me feel good. So anyway with that, Joanne, thank you. JOANNE CHANG: Thank you. Thank you, for that introduction. I always learn something from the
introduction that you give, Michael. You always explain stuff. So one of the reasons why I
love coming to these classes, I’m a nervous wreck the entire
week before, I still am right now, but in that quick 5 or 10
minutes that Michael speaks, I always learn a little bit
more about what it is that I do. Because I know how it works, and
I can explain what will happen, but I didn’t even think about what
was happening with the boiling point. We are going to boil sugar,
I’m going to show you different things you can do with
the different stages of sugar. But I didn’t even think about
the actual boiling point rising. A little bit into the
lecture, I will talk about the freezing point of a liquid,
and how when you add sugar to it actually depresses the freezing point. But I hadn’t thought about
how it works the other way. So that was really fun to learn. So thank you again for
having me back this year, and think you to Harvard
for hosting this class. And then I also have to thank
my assistant Jess, who’s back there piping lots of
little containers of butter cream and caramel sauce, and
little crispy cookies for you guys to try at the end. So there is a tasting. [LAUGHING] Yay Jess. So, the last two years
that I’ve taught here, I focused very broadly
on just the chemistry of science, the chemistry of
baking, science and baking, and I focused on making a cake. What we did was, we took all
the different ingredients that go into a very
simple yellow cake, and I talked about emulsification of eggs. I talked about gluten formation. I talked a little bit
about buttermilk, and how it reacts differently than milk. I talked about all of the different
ways you can leaven a cake, so with air and with steam,
baking soda, baking powder. You put all these things together, mix
them all up, and then you get cake. And what we did, the
last two years, is we taught about the science of
baking through yellow cake. These are some examples of
some of the cakes we did, one with no baking powder,
one with no baking soda, we did melted butter instead
of room temperature butter, we did a host of different things. And it was a super fun lecture to teach. Turns out that last year,
two of the students– so I teach the class
tonight for the public, and then tomorrow I’ll come back and
teach to the Harvard students who are actually taking this class as
a course– and two of the students last year, upon taking the
science and cooking class, and then watching the lecture
that I taught about cake, for their final project– I think
it was their final project– they decided they wanted
to do more with cake, and so they came up with spray cake. I don’t know if any of you guys saw
this, it was actually in The Globe about two or three months
ago, it was front page news. These two Harvard students
had come up with a cake that you can put– they
put it in an aerosol can. It sits on a shelf in the grocery
store, and whenever you’re hungry and you want cake, you just spray
this into a pan and then bake it. And then you get cake. So this is for people who think
they cake mixes are too difficult. And thus you just want to take
an aerosol can and spray it. But they came by the restaurant,
and they baked me some cake, they wanted me to approve it,
and see if I thought it was good, and I thought it was really good. And I have to say it was really
exciting to know that something that I had taught had
actually led these students and inspired them to create
a product, where they’re going to go off and make millions. So two questions lead
from that, and when I told my parents about this– I sent
it to them because my picture was somewhere, and they always
love that kind of stuff– the first thing my mom said is,
are you getting royalties on this? So that I still don’t know,
I haven’t heard from them, but they might be here in this room,
or maybe they’ll watch the video and so they know where to fine me. You can always tag me along. And then the other
question it raises, is that it really does up
the ante for this lecture, and can I create a lecture that
will inspire people and make people innovate something even more exciting? So a lot of pressure this time around. OK, so this time Professor
Brenner and I talked about focusing on a singular subject
rather than the broad topic of cooking and baking, and science and chemistry,
but instead on just one subject, and that is sugar. So this actually came at a great
time when Professor Brenner called me last year, because I was just finishing
the manuscript for a new book that is coming out next spring– which
is called Baking With Less Sugar– and I just spent the prior year baking
all year long with recipes that I was used to using at the bakery, but
with less sugar or with no sugar. So I had a lot of experience
baking with less sugar or no sugar, and seeing the way the recipes came
out when you didn’t have sugar. So I was excited to take
everything that I’ve learned and then share that with you guys. So you can see all the things you
can make with either no sugar or very little sugar. It turns out that
sugar is something that is genetically engineered inside of us. We are all born with
an affinity for sugar, and if you have something
sweet in your mouth, your body reads it as a
possible source of energy, and it reads it as probably not
something that’s going to be harmful. It doesn’t read that when it gets
something sour, or something bitter. And so it’s having
something that is sweet is something that we’re all accustomed
to, and that we are all attracted to. So when you think about sugar,
and what it does to desserts, what is it that defines a dessert? Well it’s got sugar in it. There are very few deserts out
there that don’t have sugar. You could have a desert that’s fresh
fruit, that’s what my parents did, they thought that was dessert. I disagreed. Or you can have, some people actually
serve cheese as a last course, I don’t know some of you guys do
that, I’ve always found that baffling. But this is also another
way people end their meal, but really, when we think
about sugar, what we think about is all the desserts
that you can create with sugar. So, what does sugar do to a desert? The most obvious one, if
I were to ask all of you, is you would say it adds sweetness. It turns out, and Jess and I spent
all afternoon thinking about this, finishing up this
presentation, it turns out that chocolate is the
only dessert that we could think of, in which sugar–
the only role that sugar plays is to add sweetness. Every other dessert
we came up with there was another role that sugar played
in making that dessert palatable. So I don’t know, I’m going to pose
that as a question to you guys. Think about all the
desserts that you know, and if you can think of
a desert in which sugar, the only role it’s playing, is to
make it palatable to your palate, to make it sweet. Then I would love to hear it,
because we had this blank at first. Because we couldn’t think
of anything that only had sugar to just add sweetness. Because sugar plays so many different
roles in every sort of desert. Does anybody have any ideas? Can anybody think of
any dessert in which the only reason you would have
the sugar is to add sweetness? The slide that we had, anybody? Yes? AUDIENCE: Milkshakes. Milkshakes? OK, I’m going to come
to that in a little bit. So I’m going to jot down
all these in my head, and then we’re going to address them. Yes? AUDIENCE: What about
a piece of chocolate? Bitter chocolate, as
opposed to sweet chocolate. JOANNE CHANG: Exactly,
so this was the only one. Bitter chocolate and chocolate,
were the only thing I can think of. We had one more, which then
we realized there was actually another role that sugar played. So I’m looking to see
if anybody would– yes? AUDIENCE: Sorbet? JOANNE CHANG: Sorbet. Goes along with milkshakes. Sorbet and milkshakes, the
sugar does add sweetness, but it also does something else. Yes. AUDIENCE: Popsicles? JOANNE CHANG: Popsicles, sorbet,
and milkshakes, all the same. AUDIENCE: [LAUGHTER] JOANNE CHANG: Yes? AUDIENCE: Zabaione? JOANNE CHANG: Zabaione. There’s going to be
another part where you’re going to see where the sugar actually
helps with the Zabaione as well. AUDIENCE: Custard. JOANNE CHANG: Pasta? Custard! Custard, yep, you need the sugar for
another reason, other than sweetness. One more thing. Whipped cream! Actually whipped cream,
you’re right, the only reason to have sugar for whipped
cream is to sweeten it. So that is, I don’t know if
that counts as a dessert, but it is just like
chocolate, it’s something that’s sweet where the sugar
is only– OK, one more, yes. AUDIENCE: Yogurt. JOANNE CHANG: Sugared
yogurt, yeah, you’re right. So sugar in that case is
just added as flavoring. So, you’re dying to give one more. For the beautiful French
macaroon, you definitely need sugar for reasons
other than just– and I’ll be demoing that as well,
we’re going to make meringue. That stabilizes the egg foams. So it turns out that sugar does so
many other things, other than just add sweetness. So I’m going to spend a little time
talking about the different roles that sugar plays in various
desserts, and then I’m going to go into the stages of sugar. We’re going to take some sugar
syrups, which are all up here, and we’re going to take
them to different stages, and you’ll get to see how they
react to make different pastries. So now I’m just going to go
through kind of a laundry list of what other things sugar does
to a desert that makes it a desert. So the first thing is creaming
the sugar into butter. So any cake recipe,
any cookie recipe, they almost all start out with creaming
butter and sugar together. You take granulated sugar,
you mix it into butter, and you cream it, what’s
called creaming, in a mixer, and you mix it, and mix it, and
mix it until it becomes light and fluffy in color. And basically what’s
happening is, I mean you guys all know the texture
of sugar, it’s very granulated, if you look at those granules
of sugar under a microscope, they’re little itty bitty crystals. And the little sugar crystals
have very hard jagged edges, and when they are mixed with the butter,
or margarine, or any sort of solid fat, what the sugar crystals are doing,
is they’re digging little air pockets into the fat. So it’s sort of like
when you’re a gardener, and you take a hoe, and your hoeing
the firm earth and you’re aerating it. And that’s exactly what
happens when you’re creaming sugar and butter together. All of those air
pockets then go on, when you’re making your cake or your cookie,
to make your final product light and fluffy and tender,
and not hard and dense. So when you think about cookies
and you think about cakes, you need the sugar to
make them taste sweet, but then you also need them in order
for them to be light and fluffy, because of the creaming properties. So this is from last
year’s lecture, we have a picture of a cake in which it’s
creamed with a full amount of sugar, and then we use half amount of sugar. And from the pictures it
doesn’t look hugely different, but if you were to
imagine a six inch cake, there’s actually about an inch to a half
an inch all the way through the cake, we noticed, when we use
half the amount of sugar. And it’s because there was half
the amount of sugar crystals to create those air pockets,
and so then the final product was able to rise quite as much, so
the cake was a little bit denser and it didn’t rise quite as much. Another thing that sugar does
is that it’s hygroscopic. And what this means, is that it attracts
water molecules that are in the air, and it brings it to itself. So this is one of the reasons why you
can take cookies, and cakes, and such, and you can package them,
and they can sit on the shelf and they won’t get stale. Because with the sugar does,
is it keeps the moisture that’s already in the
cookie, inside the cookie. And it helps it last longer, so
you can put on the supermarket and sell it for weeks at a time. Originally when we
were talking about what is a desert in which the only thing
that sugar does is add sweetness, this was the first slide
that I had because I thought, well if you take some fruit, and you
mix a little bit of sugar into it, and you sweeten it,
then that’s a desert, and the only thing the sugar is
doing is adding sweetness, right? Well it turns out not. If you look at the picture closely,
you can see in the pot of strawberries, you can see a little bit of that sauce. That sauce is because
sugar’s hygroscopic, when it mixes with
the strawberries, it’s drawing out all the moisture in the
strawberries and it’s creating a sauce. And so that’s the other
way in which sugar helps make this desert so delicious. It makes it sweet and then it
also combines with the liquid in the strawberries to make a sauce. OK, so the people who said
popsicle, sorbet, and milkshakes. This is a really
interesting part about sugar that I didn’t know from a science level,
I just knew from an operational level. That when I used to make
sorbets and ice creams, if I had something that didn’t
have a lot of sugar, it was really, really icy. And if I had something in which I had
mis-measured, and I put too much sugar, it was really soupy. And I could never really
figure out why, I just made sure that I followed the
recipe so that wouldn’t happen. But in studying more about the role
of sugar and what it does to desserts, sugar actually depresses the
freezing point of a liquid. So if we take ice, and we put it in
the freezer, you get an ice cube right? It’s going to freeze at 0 degrees
Celsius, 32 degrees Fahrenheit. If you add some sugar
to that, what it does is that it means that that sugar
water won’t freeze right at 0 degrees Celsius, but it might
be a little bit lower. And so if you have a freezer that’s at
0 degrees Celsius, then that sugar water that you have won’t freeze solid. So we use this to our advantage
when we’re making frozen desserts. So when you make a popsicle,
or a sorbet, or milkshake, you need the sugar to make it
taste good and to make it sweet, but you also need the sugar
to make it actually scoopable, so that you can eat it, so it’s
not like sucking on an ice cube. So this is a video, Jess made five
versions of grapefruit sorbet. This is just grapefruit and water. There’s no sugar. This version has a half a cup of
sugar, and she wanted me to explain it she’s holding iPhone
with one hand and she’s trying– which is why it looks
like it’s really awkward. Because we were watching it, and I was
like, why are you looking so weird? And she said that it’s
because I’m trying to hold the iPhone at the same time. This is version three, one cup of sugar. This is the actual recipe, you can
see you can actually scoop into it. This is version 4, 1
and 1/2 cups of sugar. And that you can scoop
into it, and you can see that it’s actually kind of
melted, because it’s not quite frozen. And then finally this
is two cups of sugar, this is twice the amount of sugar
that you should have in this recipe. And it’s practically soup. You can see it’s like really
syrupy, and she doesn’t even have to be so stiff anymore. AUDIENCE: [LAUGHTER] So that’s what sugar does to
popsicle, sorbet, and milkshakes. Not only does it add the sweetness,
but it also allows for a nice texture, so that you can eat it
and it’s easy to eat. Sugar also stabilizes beaten egg foams. So for the person who said
French macaroon, you need sugar, it adds sweetness, but it
also provides the structure. So that you can make
the French macaroon. [BLENDER] OK, so the first thing we’re going to
do is just a beat up the egg whites without any sugar at all. So like I was saying, you have the
protein strands of the egg whites are starting to get filled with air. And you’re going to see– like this
egg whites before they’re beaten, they’re yellow, they’re viscous. I think you can start
to see into the bowl, you can see how it’s starting
to get white and airy, that’s because all of
the air is starting to get captured within the foams. Now the protein of the
egg whites, which is now capturing all the air, those
protein strands aren’t that stable. So I’m going to whip this,
and whip this, and whip this, and I’m gonna put this out
in the bowl, but you’re going to see it’s going
to be very unstable. It’s going to look a
little bit like Styrofoam, and it’s not going to
be anything that you’re going to be able to really bake with,
because it’s going to start to deflate. We’re going to do another batch
with egg whites and sugar. So sugar, when I start to
add that to the egg whites, the sugar actually combines with
the water that’s in egg whites. So egg whites are
protein strands in water. We’re going to whip up the sugar into
the egg whites, and in that batch, the sugar will combine with
the water and it’s going to create a syrup within this foam. And what the syrup is going
to do, is it’s actually going to protect all of
the little protein bubbles that the egg whites are
forming when it goes into foam. And so it’s sort of
like packing peanuts, you know when you have
something fragile, you buy all those little
Styrofoam peanuts. And you pack your fragile items
and you put lots of peanuts around it to make sure it doesn’t break. That’s exactly what will
happen with the sugar. So you can see that now the egg
white foam is all nice and white, and it’s getting foamy. And I don’t know if you can see, but
now it’s starting to get over whipped. Because all of those proteins are being
stressed, and stretched, and stretched, and stretched, and
they’ve taken all the air they can, and then they’re
just like, OK, that’s enough, and then they start to break down. So this one– So this one, can you tell how, I
don’t know if you can really see, but it’s– you see
how deflated it looks? And it’s like, it’s
just a matter of time before all of this kind of deflates. And it doesn’t look very, I don’t know. I mean to me, this
doesn’t look very stable, but I don’t know if
you’re not a baker if you can tell that this isn’t very stable. So is there are non-baker out
there that can look at this? Does this look stable to you? AUDIENCE: I don’t know. JOANNE CHANG: You don’t know, OK. You’re going to have to take my
word for it, this is not stable. Look at it, it’s like– see? AUDIENCE: [LAUGHTER] JOANNE CHANG: It just looks
like it’s not going to last. And then, we’re going
to put it over here, and you’re going to watch it
all night long, and you’ll see. OK, so then, we’re going to do the exact
same thing, with the same amount of egg whites to begin with. But this time we’re
going to add– So the key is you have to start it really slow. So the same process is going to happen. It’s going to start to get foamy. So while this is, while
I’m waiting to add this, these are the things that you
can make– some of the things that you can make with
stabilized egg foams. You can make lemon meringue pie,
you can make angel food cake, you can make butter cream. I’m going to slowly add the sugar. So lemon meringue pie, you take
this meringue that I’m making, and you plop it on a pie, and that’s
meringue for lemon meringue pie. Angel food cake, you
take this exact meringue that I’m making– you’re going
to see how easy baking is– you’re going to fold in
some cake flour and bake it, and that’s angel food cake. And then buttercream, again you’re going
to take this exact meringue that I’m making, and you’re going
to throw butter into it, and that’s going to be buttercream. So those are some things that you
can make with sugar and egg foams. So I’m going to let this
go for a little bit, and then I’m going to
show you the difference between this one and that one. So while that’s going, I’m going to
give you another thing that sugar does. Sugar tenderizes, and
inhibits, gluten development. And I’m not going to go into
a big long thing about gluten, but basically gluten is a big buzz
word, everybody knows about gluten, it means you want to avoid wheat. Gluten are two protein molecules
that exist in wheat flour. And they exist separately until
you add liquid to wheat flour. As soon as you add liquid to it, the
two protein molecules bond together, and then they do exactly
what the egg whites do. They bond together and they form
these stretchy things that hold air. So this is great for
when you have bread. If you take bread, which is flour,
water, and a couple other things, and you mix it up, you
develop all this gluten, and you create a bread that’s really
chewy, and it has a lot of great heft, and it tastes really great. And that’s great for bread. But when you’re making a cake, that’s
the last thing in the world you want, is a cake that’s chewy and not tender. You want something
that’s light and fluffy. What sugar does, similar to what
it does with these egg foams, is that the sugar ends up
protecting those two protein gluten molecules from bonding. And so when you’re making a cake batter,
if you have a lot of sugar in it, then the sugar’s protecting
those from bonding, and then you have a cake
that’s tender, and it doesn’t have the ability to hold
all of these big pockets of air, which will give you a chewy cake. Let me show you this meringue. So this is very different. So this was the same one cup of–
I’m going to ask my friend here, does this look different? AUDIENCE: [LAUGHTER] JOANNE CHANG: So do you
see how silky that is? Where’s the camera? AUDIENCE: [LAUGHTER] JOANNE CHANG: It’s like really
silky and much more stable, and this is what you would
use to make a dessert with. And that’s just the addition of sugar. Okay, I’m going to start
getting these things going. There’s that one. And then there’s that one. OK, so a couple more
things, and then we’re going to start talking
about the stages of sugar. So sugar aids in browning. So what this means is, at 310 degrees
there are protein molecules and sugars that rearrange themselves in
a cake batter, or a cookie, or whatever, into these
little ring– this is one of the things I learned, getting
ready for the class– they rearrange themselves into these little ring-like
structures, that then reflect light differently to make
something look browner. So this is a picture of the sour
cream coffee cake at the bakery. So as it turns out, for the
new low sugar baking book, I made a sour cream coffee cake. This is the exact recipe
that we make at the bakery, except it has instead of a full cup of
sugar, it has six tablespoons of sugar. And you can see the difference in color. I mean there’s obviously going
to be a difference in taste, but there was such a
drastic difference in color that when we took this picture
for the photo shoot, for the book, the photographer kept trying
to get me to put it in the oven and brown it longer, or he tried
to Photoshop it to make it browner. And we knew that this wasn’t
a super attractive picture, because the one on the left
is what you’re typically used to seeing when you
think about a beautiful cake. But this thing is, that when
you don’t have a lot of sugar, you’re never going to get that browning,
and so we wanted it to be realistic. And so this is the picture,
something like this is what you’ll see in the book. Sugar makes pastries crispy. And so in something like a
cookie, the sugar will liquefy. It’s in the cookie batter,
it goes into the oven, it liquefies, and then
as the water evaporates, the sugar recrystallizes,
and then you end up with a cookie that’s really crispy. So you’re going to get a little
bit of a crispy sugar cookie. And it’s crispy because of the sugar. Again, I tried to make a low sugar sugar
cookie for the book, and it was soft. It wasn’t that sweet, but
it was also just soft, and there was no way we
can get it to crisp up. We ended up doing a ginger
snap, and what we did was rather than– because
it wouldn’t crisp up, because it didn’t have any sugar in
it, we put it in an oven overnight and we dried it out. And then it ended up just
being a hard dehydrated cookie. So it was sort of crispy. AUDIENCE: [LAUGHTER] JOANNE CHANG: I know that sounds
really appetizing, doesn’t it? No, it’s really good. And then finally, sugar caramelizes
between 356 degrees and 390 degrees, sugar will caramelize. And that adds to the flavor of a
cookie, or cake, or tart shell, you get that really nice
toasty, nutty aroma. OK, so the next thing we’re going to
talk about is the stages of sugar. I’m going to come back
and babysit these guys. So when you take sugar and
water and make it into a syrup, and you boil it at the
various temperatures that you boil the sugar water
to, it corresponds to the way the sugar reacts in cold water. And so the first stage is thread stage. This is the easy one, you just boil it. At 230 degrees to 235 degrees,
it’s called thread stage. If you pour a little bit of this into
some water, you’ll get little threads and then it goes to the bottom. This is used for sweetening iced
tea, or just glazing fruits. The second stage is soft ball. At soft ball, which is what I’m
taking this to, you can make fudge. I’m going to take my between soft ball
and the next one, which is firm ball. So at firm ball, you can make caramels. So these are the
difference in temperatures. I’m going to go backwards. So if you look at soft ball, 235 to
240, when you take the sugar water and you put it in cold water,
you’ll get a soft ball. That’s how it got its name, and
then with firm ball, when you do the same thing you get a firm ball. And that’s how, so you don’t
need a candy thermometer, because you can just use your hands. But the thing is, is
that it’s really hot. So you have to first
freeze your fingers. And the other thing
that you can do– and I don’t know if you can hear
it because I’m talking– but when you hear sugar water boil,
it just sounds like water at first. And then, as it starts to get more and
more concentrated, you can hear it, and it starts to thicken. And when it gets to
the right temperature– and this is only because I’ve
been doing it for years– you can actually tell when it’s
hitting about soft ball stage. So that way you don’t have to
plunge your finger in all the time, you can wait. So can you hear it? It’s a little bit slower now. So now I’m going to take a little bit,
and now I’ve gone a little bit too far. No here we go, firm ball. You can’t really see that, but
there’s a firm little ball. OK, now we’re going to make meringue. So this is very similar
to the meringue that we made that’s sitting
over there in that bowl, except that I’ve cooked the sugar. This will help make it–
that meringue, is not quite as stable as this meringue. So I’ve just taken that sugar syrup,
and I’ve poured it into the egg whites. I’m going to take this Italian meringue,
and I’m going to throw butter into it, and then that’s buttercream. And that’s what you use to frost a cake,
and that’s what you’re going to eat, is a little bit of butter cream. OK, but you have to wait until this
cools before you can add the butter. So while that’s cooling, I’m going to go back to
this slide really quick. Hard ball is what you
use to make marshmallows. And then soft crack, is taffy. Hard crack is lollipops. And then the final
stage, is caramelization. And that’s when you take the sugar
so far that it starts to turn tan, and then it starts to
turn brown, and you can make praline, and caramel sauce,
and a whole bunch of other things. So does that makes sense? All of the stages of sugar, and
why they have the different names? OK. Because you can definitely
use a candy thermometer, but if you know what you’re
looking for, you don’t have to, and you can just use ice water. And then you’ll know
exactly how far to take it. OK, so let’s revisit these meringues. You can see this one. So can you see, this is the one that
was just egg white, and no sugar. And it’s basically just deflating
in front of our very eyes. It’s very sad. Useless. This has been stabilized with sugar. So you can see it’s still beautiful,
you can make cookies out of this. You could fold almond flour,
and make French macaroon, that’s what you’d use this for. The Italian one, which is over there,
we’re going to wait until it cools, and then this one we are
going to make praline. Praline is when you take sugar,
and you wait until it caramelizes. So right now it’s reaching
about firm ball, hard ball, because it’s really,
really slow in its bubbles. And the bubbles are getting
really big, they’re very slow. And now it’ll slowly
start to turn color. And as soon as it starts to
caramelize, to make praline you just pour nuts into it, then
pour it out onto a sheet tray, and then let it cool. OK, so while that one is
waiting to caramelize, we’re going to add the
butter to this one. Sorry, I don’t mean
to keep moving around. Can you see how much this has grown? I don’t know if you guys can see that. So to make butter cream, you just take
the butter and you just throw it in. It’s got to be soft butter,
it can’t be too cold or it’ll shock the whole thing. But it can’t be melted butter, because
then it won’t be stable enough. And it’s about a cup of egg whites, a
cup of sugar, and a pound of butter. Does that sound like a lot? I feel like this is such a small amount. Like, I’m almost done. And what will happen is, as the butter
will slowly mix into the meringue, and it’s going to look broken at first,
it’s going to look like we messed up, and then slowly it’ll all come
together and we’ll have buttercream. OK, so that one is working. And now, we’re going to come back here. And now you can see, you see that? How nice that looks? So I’m just going to swirl this
around a little bit, and add my nuts, swirl to coat. And probably about 10 or 15 minutes
will cool, and it’ll be really hard, and then you can break it off
and some people can eat it. Because we only have this much. So we’ll put it right there. We’re going to make caramel
sauce, and then we’re going to finish with croquembouche. Which is the picture that the
beginning of the slide show began with. So right now I’m just adding
water to the sugar to dissolve it. And then we’re going to take
it just as far as we took that. And this one we’re waiting
to get a little bit brown so that we can make caramel sauce. OK, so here we go, we’re going
to look at the butter cream. And so this is buttercream. And this is what you
would use to frost a cake. So if you want, you can
make this ahead of time– I know this isn’t a baking class–
but just so you know, if you want, you can make this ahead of
time, store it in the fridge, and then when you want to reuse
it, you don’t want to use this. You actually want to
use this, to repaddle it and to make it smooth again. It’s going to be hard like butter,
because it’s mostly butter, so you’re going to want to bring it
to room temperature and paddle it. And it might break, it
might look curdled, but just wait until it warms up and then when
you paddle it’ll get smooth again, and then you can use it. Any questions? No? OK. Cause we just have to
wait for these two things. The timing with caramel
is a little bit tricky. So we’re waiting for this to
caramelize, and then we’re going to do the croquembouche with this. That’s all I have. [LAUGHING] MICHAEL BRENNER: Can I actually
take the time to say something? About the boiling point, again? So if you noticed on Joanne’s slides, as
she was going from softball to hardball to whatever they’re
called, what was increasing was the percentage of
sugar in that thing. And it’s really dramatic, that
it’s only a couple of degrees and the sugar percentage
goes up from like 85% to 95%. So what’s the rest of it? Other than sugar. What else is in there? Where it says 85% sugar,
what else is in the mixture? Water. And so the reason that the
textures are so different is because you know if it’s all
sugar, it’ll be really hard. But see at 95% sugar then the
texture is softer, 92% it’s softer. so what you’re really
doing is controlling the water content, of the mixture. JOANNE CHANG: So, we’re going
to now make caramel sauce. So you can see, that it’s
now nice and caramelized. And one trick– again I know
it’s not a baking class, but just in case you guys decide to
make something– when you make caramel, right now it looks really brown, but
the real key is, what you want to do is, actually tilt the pan,
and then look at what results. Because that’s the true color. So I think a lot of bakers, they
think, oh, this is caramel, I’m done. But no, this isn’t dark enough. What you want to do is take
it, tilt it, and then look and then that fine
sheen is the true color. OK, now it’s good. And then we’re going to add cream,
but you have to be really careful because it’s– and that’s caramel sauce. And then this one, this
is the last one, which is, I’m going to do what’s
called spinning sugar. And that’s taking caramel,
and then creating– because remember how we
talked about soft ball, firm ball, hard ball, soft crack, hard
crack– it turns out at hard crack and beyond, what that means
is that when the sugar cools, it becomes like a crack. It cracks. And caramel, which is way past hard
crack, when you flick it really fast, it creates these long sugar strands
that end up looking very beautiful, and that’s spun sugar. And last year when I did
it, I had a pot of sugar and it crystallized in the middle of the
lecture, and I was like, what do I do? So crystallization of sugar is when
you’re doing what we’ve been doing, you put sugar and water in
a pot and you turn it on, you think you’re making either
softball for a butter cream or you’re making caramel for
caramel sauce, and you come and you look at it,
and all of a sudden– and I was actually worried
that that might happen tonight, but I probably should have let it
happen so that I could show you guys. So when you come back
and you look at it, it turns out it starts to have– I
don’t even know how to describe it, it kind of looks like pieces of
ice floating in the sugar syrup. So everything that you’ve
seen, has been perfect. Everything’s boiled,
this look so perfect. It’s just boiling and boiling. But it turns out, there’s a couple
things that cause crystallisation. That I know of, from a
pastry point of view. I don’t really know what it means
from a scientific point of view. But if you have any sugar crystals
that are on the side of the pan. So when you take sugar and
water and you mix them together, you don’t want to splash
sugar crystals on the side. You may have noticed that
when I put the water in, I didn’t just pour the water in. I very gently put the water in, I really
gently moved the sugar to dissolve it. Because if there’s any sugar
crystals on the side, then there’s a chance that those sugar
crystals, they’re very influential. And when this is happening,
it’s at this point when it starts to go into soft
ball, firm ball stage, but if there’s a sugar crystal, the
sugar crystal will fall into the syrup and it’ll just cause this chain
reaction that will then cause what looks like ice on the top of it. And it can happen at any stage. The other times it
happens is if you move it. So I don’t know if you’ve
noticed, but I won’t touch this until it starts to caramelize. So if you move the sugar syrup while
it’s boiling, it for some reason jostles it and makes
it want to crystallize. And so those are two tricks. You want to make sure that there’s
no sugar on the edge of the pan, and then you don’t want to
touch it until it caramelizes. As soon as it caramelizes,
you can touch it. And you can swirl it around,
and even out the caramelization. But before then if you touch it,
there’s a chance it will crystallize. Some things that you can do, you
can try to just boil it gently, and sometimes it boils away. But a lot of times you
just have to start over. And so like during the
holidays when we’re making millions and
millions of croquembouche, we have pots of sugar
just going on every stove because one out of every
ten ends up crystallizing, and then we can’t use it. So we always have these backup pots. MICHAEL BRENNER: Is that? How’s that? JOANNE CHANG: Yeah, I think
let’s do this for a sec. So the sugar actually started to
crystallize, which is too bad. OK, so now you can see,
so this is caramel right? We’ve made it, and we let it sit,
and now it’s starting to cool down. And as it cools, it thickens up. And then– so what I’m
doing is, I keep lifting it to see if it’ll just fall in one
continuous strand without breaking. And then once I feel like
it’s a nice thick layer– I’m going to try not to make
too much of a mass here. So then what you can do is just
do what’s called spun sugar. Which is you basically– So I let a lot of it drip off,
because I don’t want clumps of it, and then I just flick. And you can see that
it just starts to fall, because it’s past that soft crack stage. I mean there’s a lot of
different ways you can do this, and typically you should do
this on a piece of parchment, it makes cleanup a little bit easier. I’ll do that tomorrow, I forgot, sorry. OK, and then so this is
just the start of it. So then you can take all of this
spun sugar and just wrap it around. Here, I’ll go this way so
that– but it’s super easy. You just hold this, and then you flick. So you have to flick. It’s a really quick, quick flicking. So a lot of times people do this,
I’m going to show you what not to do. So a lot of times
people will do this, OK. But what you want to do is,
again let a lot of it runoff, and then just flick really fast. And then as the sugar
falls from the utensil, it’ll form these strands
that then become spun sugar. And so then as this gets
colder, it becomes harder to spin because the sugar gets
more and more firm and hard. And then you can do what’s
called pulled sugar. Actually, you would never take
it to caramel to do pulled sugar, but if you take sugar to hard
crack stage and then let it cool, it becomes stiffer as it cools. And as it becomes stiffer,
you can start to lift it up, and it starts to feel like
caramel, and you start to pull it. And that’s how they make all those
beautiful flowers, and birds, and butterflies, and stuff like that. So this is, you just keep going
until you cover it, and as much caramel as you want. The tricky thing about
croquembouche, and about spun sugar, is that it’s very temperature dependent. And it’s very humidity dependent. And so you actually
can make it, and it’ll last for about an hour or two hours,
and then it just starts to melt. And if it’s raining outside,
you don’t even have that long. You probably have like 15 minutes,
and then it just starts to melt. MICHAEL BRENNER: Can I
ask you guys a question? So why do you have to flick it? Anybody know? It has to, it has to hit air. So somebody said cool
rapidly, so when you flick it, I think you evaporate the liquid out
faster, and it solidifies faster. If you go like this,
it doesn’t evaporate, so probably it’s liquid when it
comes down if you don’t flick it. JOANNE CHANG: I think because as
it cools– so if I just take it, and just move it– MICHAEL BRENNER: You’re just pouring. JOANNE CHANG: Yeah,
then it’s just pouring. So it’s not really, it’s like– MICHAEL BRENNER: When
you move something, so there’s this wonderful
experiment that we’ve all don, that if you blow
on a spoon that’s hot, it cools faster, then if you let
it– And that’s because evaporated, you carry the heat away faster. Sort of evaporates faster. So should we– I think we
should take more questions. Let me propose several things. First, I think we should all clap. AUDIENCE: [APPLAUSE]