CHRISTINA TOSI: And I was raised by this funny mom that loved to make box cake,
and I was raised by grandmothers.
And they made frosting one way, and honestly, that
is the way that we make frosting today.
We don't make boiled frosting, we don't make anything other than this frosting.
And it's really simple and it's really easy to alter the flavors of it.
It's butter, unsalted European-style butter.
It's confectioners sugar.
We paddle those two suckers together until the butter has broken down.
We're going to make this frosting into coffee frosting.
When we are creating recipes and we're trying to figure out what we want,
what flavor we want and what vehicle-- so in this case coffee
into a frosting-- we have so many decisions we have to think about.
One, what kind of what type of frosting do we want to make?
Inevitably, it comes back to this very simple style of frosting.
And how are we going to get the flavor in?
So when you think about coffee, it's like, OK, we can do this.
I could skin this cat so many different ways.
I can just add coffee, but coffee is largely water-based,
so it's going to all alter my volume.
It's going to plummet.
JENNA: It's going to plummet the volume fraction.
CHRISTINA TOSI: It's not good, it's going to separate,
it's not going to emulsify.
It's not good, no one wants an unemulsified frosting.
Would you hand me one more spatula?
JENNA: Yeah, of course.
CHRISTINA TOSI: I can add espresso.
Espresso works.
Espresso is a little bit bitter, and I don't know,
I don't want it to taste like espresso.
I want it to taste like coffee.
What else could I do?
I could melt the butter and try and brew coffee through it,
or try to do a pour over with coffee.
I start going in all these places, of like OK, how can I do it?
We tested so many different recipes for coffee frosting,
and we ended up taking whole milk, instant coffee, and some kosher salt.
The instant coffee really allows you to get a depth of flavor in there
without having to add too much milk.
So you can really, really control the depth of flavor
against the amount of milk that you're adding in.
The hardest part about creating something
is it's really easy to dream up an idea, but it's really hard
to make it into a reality.
And the hardest part about something like this coffee frosting
is I know I need to add coffee in some in some degree.
The instant coffee really needs the milk to dissolve itself.
We don't-- I mean, maybe some of you eat instant coffee granules-- but I don't.
I want it to be smooth, and I want it to have the flavor of coffee.
I can't just paddle instant coffee into my butter.
I need enough liquid to hydrate that instant coffee into a coffee flavor.
But I also know that I only have a certain allowance
for the amount of liquid that I can add into this frosting before it breaks
and it separates.
And this coffee frosting literally comes right up
to the line in terms of keeping that emulsification intact
and separating it out.
And that is the hardest part of the job, where
it's like knowing when to say when.
I wish that more of us took these classes
to be able to really calculate the math and understand.
We understand why it's happening and we understand how it's happening,
but sometimes we don't understand what the very, very, very, very, very--
what the tipping point is, and what amount
we can add before it tips over and so on.
And that's the coolest part of the job, too.
It's sort of getting to learn about the scientific process through something
as simple as, all right, I want to make a coffee frosting,
but it needs to be able to be smooth enough to spread.