Original subtitles

welcome to today's installment in the

beginner's guide to coffee and today's

video

is all about steaming milk here's how

it's going to go first of all we're

going to jump straight into the

technique

how to steam milk to get a really fine

moussey texture of foam

that you can use to pour latte out if

you want to or just drink and enjoy

because it feels so good

once we've understood the technique then

we'll dive into a few more bits and

pieces we'll cover

the science of this stuff we'll cover

alternative milks and different kinds of

dairy milk

we'll cover troubleshooting and make

sure that not only do you understand how

to steam milk but what to do

if you have a problem and it doesn't go

the way you want it to so let's start

right at the beginning with how to steam

milk the technique

of it now this is a technique you're

going to use for any machine

that has a traditional steam wand that's

generally got a metal tip on the end

with one two four holes where steam

comes out now not all machines have

traditional steam wand

tips so if yours doesn't have that it

might have a weird little plastic wand

or

some level of automation really the

answer is read the instructions and do

what the manufacturer tells you to do

but if you've got a traditional steam

wand you should be able to create

really beautiful milk texture so where

to start

well first of all you're going to start

with cold milk so we're going to be

steaming in a stainless steel pitcher

that's useful because you can touch the

side and feel exactly how hot the milk

is

we'll come to that the size of the jug

determines the amount of milk that

you're going to steam right you don't

want to steam in a massive jug just a

little bit of milk and you don't want to

steam a lot of milk in a small jug so

work appropriately you never really want

to fill a jug above

where the spout starts on the side here

right that's a good

max line for for most jugs in my opinion

you'll add some volume to the milk when

you steam it and the motion of the milk

and the jug will drive it up the side of

the wall

so if you feel above this line you risk

a terrible mess

so that's your kind of max limit and you

can get various sizes of jugs this would

do

like an eight ounce drink or a 250 ml

drink quite comfortably if you're doing

them one at a time you could probably

squeeze two smaller drinks out of it if

you wanted to then you're gonna add cold

milk now

we'll talk more about different kinds of

dairy milk and non-dairy milks later on

i'm not gonna use dairy because i don't

drink dairy i'm gonna be using this

because i helped develop it and i really

like it and it steams just like milk

now for the sort of theory practical bit

of what we're trying to do you're trying

to do three things when you steam milk

firstly you're trying to make it hot as

long as steam is going into milk as long

as the process is happening

that's happening so your milk will heat

up in a pretty linear way

during the sort of steaming section so

that's number one trying to heat the

milk

no hotter than 65 degrees celsius i

would say

i'll explain later on why now there are

two other things we want to focus on

when we're steaming milk

and we're going to look at those kind of

one at a time in the process so the

first thing we're going to do and we'll

start doing it as soon as we start

steaming milk

is essentially blowing bubbles to make

foam

we have to inject air into the milk and

we can do that using the very tip

of the steam wand when that sits on the

surface of the milk

then the pressure of the steam coming

out of the wand drags in

air from around it into the milk and it

essentially blows big bubbles

and the more bubbles that you blow into

the milk the foamier your milk is going

to be

now you want to do this part of the

process really as quickly as you can

not so quick that you lose control over

it because you

you know you want to do this with some

intentionality with some purpose

but you want to get it done pretty

quickly because the second thing you

want to focus on in the second

really two-thirds of the process is

texture

we're going to use the steam wand like a

hot whisk and it's going to take our big

bubbles that we blew at the start

and whisk them down smaller and smaller

and smaller and smaller and smaller

until they're so small they're pretty

much invisible and at that point you

have what's called microfoam you have a

foam that

feels just marshmallowy and soft and

beautiful to drink

and you've made a great drink right that

that's the goal

so we're gonna heat milk for the

duration at the start we're gonna add

our air

and in the second two thirds we're gonna

texture that foam we're gonna whisk it

down

to the smallest bubbles we can make now

let's look at how you do that in a more

practical sense now steam ones and most

machines have some movement to them and

generally

you want to have it pulled away from the

machine sort of pointing out towards you

kind of a little movement there there

but obviously don't do something weird

like that i would say just

just away from the machine a little bit

and that's good now to line things up

you're going to use the spout of the jug

your steam was going to sit

inside that spout right so you can just

slide it

all the way now putting the steam wand

into the milk you only want it to go

as deep as the tip on the end of the

wand right you can see there's always a

join where that tip meets the rest of

the wand

no deeper than that there's no point it

doesn't help you out so just that deep

the last thing to do is to add a little

bit of an angle to your jug

right like you tilt your jug for most

people slightly to the right but you can

tilt to the left it depends on the sort

of space around your machine but

you know not dead on slightly angled

we're going to do that to help with the

second stage where we're trying to whisk

the milk around

before you start to steam do make sure

you purge your steam wand

in many cases you'll have a little bit

of condensation that you want to get rid

of and get that out

in other cases you may actually have a

little bit of air still in the system

and you don't want to accidentally blow

a big sort of uncontrolled bubble into

the milk right so

just purge the wand to get it ready to

go then

get the jug into place now to explain

the process a little bit better

before i do it what i'll do is i'll show

you steaming

water to explain the position of the

steam wand while we steam because once

you're steaming it's a little bit more

difficult to talk about

so you've got your jug in place right

the angle is right

the steam wanted tip is just under the

surface and then you're going to start

to steam and then just about every

machine out there

you kind of want to go straight to full

power right you don't want to go to half

power a little bit you just go

on and i like machines that just let me

go straight all the way to on now as

soon as you turn the steam wand on you

want to begin to lower the jug to bring

the tip

right to the surface of the milk right

not quite above it but just to the

surface

and you know it's in the right spot

because you'll begin to see

and hear and feel air being blown in

right

you'll be able to hear a kind of

slurping noise feel the kind of

vibrations

of the steam blowing bubbles in the milk

you want to do this to create as much

foam as you need for the drink that

you're making

for example if you're making a

cappuccino i would say you want a good

amount of foam you want to have the tip

on the surface until you've created

say an additional 50 to 80 in volume

right that will give you lots of foam

if you're trying to pour fancy latte art

you maybe want to add 20 to 30

volume only so that you have a thinner

foam at the end of it

either way you're trying to get this

done really early in the process and as

soon as you've added as much air as you

need you're going to raise the jug back

up

and stop the foaming process all you

want to do is see the milk

roll and spin and churn and that's why

we had our jug

at that angle to help create that vortex

where the steam is just going to be

whisking and swirling

all of those bubbles smashing them down

to be smaller and smaller and smaller if

you're comfortable use your hand on the

side of the jug

and when you reach the point of

discomfort you're probably around 50 to

55 degrees celsius

going on another three or four seconds

will get you close to

60 which i think is a great drinking

temperature

and another two three seconds maybe if

you want to go to 65 which is where milk

tops out so that's the process and i'll

do it

again now live and go through in real

time how it would be

to foam milk jug is in off to a side

hit steam

lower the jug

you can hear that slurping sound

and when i've made enough volume i'm

just going to raise the jug back up

and go into that churning phase

getting close to about 55 degrees c now

take my hand off

first thing you should do is put the jug

down forget about it for a second

clean your steam wand pudge it out you

actually want the jug to do

nothing at all for a little bit and i'll

tell you why even the most practiced

person can end up with a few

slightly larger bubbles than they would

want the process of pausing here before

you tap

allows those bubbles to get weak and

then they pop easily and then you can

begin to swirl the milk and foam

together again

until you see a gloss finish in the jug

at this point you can pour this into

coffee and create a beautiful drink and

you can pour

the milk and foam together because

there's enough liquid in the foam

that it'll pour if you look in the jug

and it has a matte finish when you tilt

just liquid milk will come out and the

foam will almost sit as a raft and sit

back from the edge and you won't have a

good

time so really really really make sure

you mix the two together

it should be a gentle mixing motion

don't be too aggressive you don't want

to make new bubbles

but you just want to make sure that

you've got the silkiest

most kind of glossy looking milk before

you pour it into your drink

so that's the process that's how to

steam milk and really all you're

changing for different drinks is how

long you're doing that kind of

stretching phase for that kind of

foaming phase

at the start of the process everything

else whether it's kind of thick moussey

cappuccino foam

or very thin quite you know delicate

foam they might want for a flat white

it's the same process otherwise right

like it's the same

start cold add the air churn it around

as much as possible

and stop that's it seems pretty simple

but it goes wrong for people in lots of

different cases and we should talk about

why

and let's briefly talk about the science

of milk foams it does become relevant

later on when we get into

troubleshooting

so let's talk about foaming agents in

things and we've touched on these before

in other videos but a quick recap now

it's it's proteins in the milk that are

involved in the foaming process

primarily

and the way it works is this they're a

little bit like a little simplified but

kind of long noodles that are all kind

of coiled up and wrapped around each

other

because parts of it really are repelled

by water

right they are hydrophobic and they face

each other giving it its shape

now when you very slightly denature that

protein and there's a couple of

different ways to do it you can heat the

protein up

or essentially you can do it through a

whisking action right if you think about

say a meringue

that whisking action is actually

denaturing some of the proteins in the

egg white

and forcing the bits that sort of hate

water to come away from each other

and at that point the bits of the

protein that hate water are trying to

find

anything that isn't water and what we've

done when we foam milk

is create a big air bubble that's very

appealing to the bits that hate water

and so what happens is that the protein

wraps itself around the air bubble on

that surface

thus making the bubble strong it's

called a surface active agent or a

surfactant

and and that's what makes milk foams

stable or egg white foam stable

in fact most foams work in this way now

what we're doing when we're steaming

milk is actually

mixing those two things into dna to the

proteins right we are

whisking with the violence of the steam

growing into the milk as well as heating

it up right so very quickly very

effectively

we can denature these proteins to the

extent that they will wrap themselves

around air bubbles if you're trying to

foam

cold milk for something you'll notice it

can be done it just takes an

enormous amount more effort and heat is

a really nice kind of shortcut which is

why

steaming can happen so effectively and

still get such good

texture at the end of it so that's why

things foam and

anything that has surfactants in it will

foam

and that's why a great way to practice

steaming milk

is not to use milk but to use a little

bit of water

with a drop literally a drop of washing

up liquid let me show you this is a

super good way to practice with as

little waste as possible

but really we're talking like a drop and

this you would go through the same

process you would steam the same way

to get a very similar result

so that's the why things foam part but

let's talk about why things may not foam

properly and for that we need to discuss

fat now

if you've made meringues you will know

that you should not get any egg yolk

into your meringue mix

because that will cause trouble because

the fat there offers kind of competition

to the air bubble

it's not water either and so the parts

of the protein that are looking for

not water will happily sort of wrap

themselves around fat

so fat destabilizes foams in many cases

there are exceptions to this and it does

get complicated

but it is basically true in most

culinary cases

and certainly it's an issue with milk if

you steam whole milk alongside skim milk

you'll find it's

much easier to sort of foam or

essentially make more volume

in the skimmed milk air that you put in

stays in whereas with

full fat milk you have to work a little

bit harder to increase the volume that's

because that fat is kind of competing

with the air bubble for the protein's

attention now again in the case of dairy

milk fats are important here

because of the way that the fats in

dairy milk break down a bunch of those

fats are called triglycerides you've

probably heard that term at some point

it's a

glycerol backbone with three fatty acids

attached to it

when that breaks down you get your free

fatty acids and you get free glycerol

free glycerol in milk is highly

competitive with air

for the protein's attention milk that

has been exposed let's say to a ton of

daylight

will foam worse than milk that has been

properly stored so generally

milk foam is better the further it is

from it's used by date because it's it's

the sort of breakdown of these fats that

reduce its foam ability and milk that

foams badly or milk that has this issue

you'll hear it almost fizz in the

picture afterwards if you lift it to

your ear

you'll hear a kind of popping sound of

all of the bubbles just popping away and

you'll have probably experienced this

and sometimes dairies say oh it's we

changed the feed of the cows or

some other thing it's often just poor

handling on the supply chain though

in some cases yes it is indeed feed that

changes the sort of nature of the fats

in the cow's milk so in some cases if

this is happening to you you do

everything right and then

just these big bubbles appear in the

milk afterwards and it kind of feels

like it's breaking down

it's not your fault it's the milk and

there's some free glycerol in there most

likely

causing you some problems the fat has

begun to break down

and there's nothing you can do to to

make that steam any better

there's nothing you can do in terms of

technique or anything else that milk

will probably taste completely fine if

you want to use it for something

but it isn't going to be great to foam

with ever no matter what you want to do

one quick thing about fat that's also

worth noting is that fat affects

flavor release in a in a drink a full

fat cappuccino

will have a different flavor profile to

a skimmer cappuccino

in a skimmer cappuccino you'll have a

strong burst of coffee flavor that won't

really

linger but with a higher fat content in

the drink you'll have a less intense

release of flavor

that goes on for a lot longer and i

think that's kind of an interesting

aspect of

how fat influences flavor so now we need

to talk about temperature

because i've given guidance on

temperature i've said 55 is is a kind of

good starting point to be turning it off

from

at that temperature it's very drinkable

straight away it's nice sweetness

but no hotter than 65. and really that's

because at 68 degrees celsius

milk begins to permanently irreversibly

change

think of it like cooking an egg once

you've cooked the yolk there's nothing

you can do to

undo that process it's a permanent

change to the proteins they've been

permanently

denatured above 68 degrees celsius

proteins begin to permanently break down

and in some cases

literally just break apart and you'll

get the release of some things that add

some kind of cooked unpleasant eggy

smells to the milk and that's

unavoidable

if your milk spends time above 68

degrees celsius

you will break it essentially and it

will not taste as nice

and that's why really great cappuccinos

are never really that hot now

because of the way that heat affects the

proteins if you steamed up a batch of

milk

and you didn't pour it out of the jug in

fact you just let it cool down and put

it in the fridge

chilled it back down again when you

steamed it the second time

the proteins would begin to fall apart

earlier because they've been

affected the first time you steamed them

the first time you heated them

so that's why you can't really

effectively reuse milk for steaming

and have it taste as good or produce as

good a texture you've just

damaged the proteins twice too much too

many times and they can't give you the

texture or the flavor that you want now

the perceived sweetness of the milk is

kind of interesting that's also

temperature related

the the sugar in milk in dairy milk

anyway is typically lactose

and and that's designed to be at its

sweetest at body temperature for i hope

fairly obvious reasons but the further

you get away

from body temperature be it hot or be it

cold the less intense that sweetness

will be perceived so

very very very hot sort of cappuccinos

or flat whites will taste less sweet

than pleasantly hot ones and if you let

it cool a bit more it will get sweeter

and sweeter and sweeter now with

alternative milks

the profiles of sugars are a little bit

different sucrose has a different curve

of temperature to lactose

so you might notice some differences

there but with with lactose in

particular there is quite a distinct

curve of sweetness around temperature

now i did say we talk about alternative

milks because they are increasingly

popular and common in cafes and in homes

all around the place

uh and generally the sort of rules of

why they would foam and the textures

they create are are pretty similar now

as i said i have a vested interest here

and in creating a product to foam like

milk

yeah you're thinking about how to use

something like coconut for like a fat

content or

how to use oat for sweetness or fava

beans for a foaming aspect there

to create a kind of plant-based

alternative and and doing that

well is difficult making something that

foams like milk is difficult

but there are more options out there in

the world today like i can't deny that

that's the truth there are things that

just don't work as well if you're

testing them out you'll find that some

out there don't foam as well or don't

retain or hold the foam as well

you'll find some variances of texture of

mouth feel all of those kind of stuff

because getting the sort of fats to work

in conjunction with the foaming agents

is always kind of tricky but it feels

like if you don't want to drink dairy

there really are more options than ever

and i would say you should be able to

treat it

exactly like dairy in the foaming

process so the last thing i want to talk

about is actually steam wand

tips or how to set up a machine to steam

well

because there's a thing that we need to

talk about here which is the idea of

almost

pressure versus flow when it comes to

steam many steam boilers are set to a

particular pressure you'll see a gauge

that might say 1.2 bars or something

like that that's

how much team pressure you have and i

would say generally

lots of pressure one plus bars of

pressure

is good and if you're struggling to

steam milk lowering the pressure

actually doesn't help you out because

that pressure is what's going to be

spinning the milk round

lots of pressure helps create a vortex

in the milk but you might experience a

situation where you're trying to steam

just a little bit of milk

and it feels like there's just too much

steam to work with and the process is

over before you've begun

in those situations that's where you

want to switch out the tip of the steam

one for something like a low

flow tip the pressure of the steam

coming out remains the same

but less steam is able to escape that

will slow the process down

it'll give you more time to do what you

need to do to add air at the start and

to do the texturing rolling vortex in

the second

two thirds it's definitely something

that's easy to do with most machines

they're relatively universal in terms of

threading on them and for most machines

there are options available for the size

of the holes and the number of holes in

the steam tip

so if you're struggling don't reduce the

pressure

reduce the flow change the steam tip

that's my my kind of advice for steaming

very small amounts of milk now i don't

know about you but i think i have

deserved a little cappuccino so that's

what i'm gonna make this is about 150

mils i'm going to put a short double in

here

we're not going to get into recipes

today that is going to be a separate

episode of the beginner's guide to

coffee where we'll go through

all of the kind of key espresso based

drinks and cover off

the kind of recipes and recommendations

around those kind of things but

in this case i'm going to pull a shot

steam some milk and pour

a delicious drink just the texture

of well-filmed milk is just a wonderful

thing to drink but now i want to hear

from you down in the comments below tell

me

what are you struggling with with your

milk steaming did this help did this

make sense of the process a little bit

more

was this a problem solved for you or is

there still something

that's frustrating you let me know down

the comments below

share your problems we'll see if we as a

community can help you out but for now

i'll say thank you so much for watching

and i hope you have a great day