Frothing. Steaming. Foaming. Whatever
This is the typical talk of espresso newbies. Not because they are putting down the art of frothing milk, but because it's so easy to get frustrated by it all. Frothing milk for your cappas and lattes really is an art, but it's an art that can be learned. With enough patience and finesse, even a stovetop steamer or a "steam toy" (one of those budget espresso machines you see at Walmart for $39 by companies like Salton and Delonghi) can produce great foam and steamed milk. That's right folks, you don't necessarily need a $1200 Pasquini Livia 90 or a $400 Rancilio Silvia.
The catch here is speed, and style. Speed is what you get on a $1000 machine. You get even more of it on a $10,000 machine like a La Marzocco. You won't get speed from a $150 machine, but where you lack speed, you can make up in style.
I actually have two styles, or ways, to froth milk. The beginner style is what you see on this page. If you'd like to see my advanced instructions, I have a special page just for it, but please read this page first before jumping over to advanced. You'll know why after reading through this.
Step 1 - The Right Tools for the Job
Start with relatively cold milk. I simply don't buy into the idea that your milk has to be ice cold, and only a certain type. I've frothed with near room temperature milk (about 60F) and with all sorts - skim, 1%, 2%, Homo, and even half and half. And I've managed to pull off some excellent froth... but there's a caveat. Very cold milk froths easier than not so cold milk. Also, skim milk and homo seem to froth easier.
I also highly recommend a stainless steel frothing pitcher, about 14-24 ounces in size, which can be bought at most kitchen supply stores for around $5-$15. Forget the wide-brim pouring models - get one with a long, narrow pour spout. And while you're there, pick up a needle thermometer, on that has a dial on top, it should read up to 220F or so.
Step 2 - Initial Technique
Basically, you have to learn how to hover the tip of the steaming wand at the right point between the starting foam (which is usually very light and big bubbles) and the surface of the milk. Sound is key here. If it sounds like you're "blowing bubbles" through a straw, you're too high, or you don't have enough steam pressure.
If it sounds like a deep rumbling, "sum serious kinda shit is goin' on here" kind of sound, you're doing it right. Your milk also appears to be getting "bigger" in the frothing vessel... if it is, systems are a-ok. By the time you reach 100F, you should have at least half the total volume of foam you expect to produce.
Step 3 - Middle Technique
Once you reach 100F and have lots of foam, you need to move the frothing vessel lower and lower, always keeping that balance between the surface of the ultra thick milk (the real froth) and the light airy big bubble stuff up top.
Step 4 - Finishing Technique
Eventually, you'll hit about 130F, and hopefully by that point you'll have enough froth. Stick the wand midway down into the real milk, and froth to 155F. (you did remember to put the thermometer inside the frothing pitcher when you started?)
If you don't have a thermometer, go by feel. If the steel frothing pitcher is too hot to touch, then you are around 150F to 160F or higher. You should occasionally touch the sides as you froth feeling it. When it gets far too hot to touch, stop. The last thing you want is boiled milk.
Pour your froth in a nice even way - properly frothed milk never needs to be spooned out, it should be poured. The only time you use a spoon is if you're withholding froth, and pouring for a latte or cafe au lait that doesn't have a lot of froth.
On most budget machines or stovetop machines, this process takes at least 2 minutes for about 6-7 oz of milk, which is the normal volume you'd work on for two cappuccinos. On a more expensive machine, or one with a larger boiler, it can take as little as 25 seconds. On such a machine, you have to be really dilligent and cognitent of what's going on, because you basically have about 20 seconds or less to build up all your foam. And because larger boiler means more powerful steam, be careful not to send milk flying everywhere.
Another note - the above is a technique that applies to a) machines with a frothing wand with no gizmos attached to it, and b) applies to the steaming of about 6.5 oz of milk. Vary the volume, and the times and indications change.
Advanced Frothing Techniques
Once you have progressed with beginning frothing techniques, outlined above, it's time to move on to the 'big boy" stuff. Microfoam and a finished product capable of true latte art. Here's what you need to do.
Step 1 - Have the Right Tools
As I said above in the beginner instructions, you don't necessarily need a $400 machine to produce great foam. But you should have the following items: cold milk; a 16 oz or bigger stainless steel pitcher; a needle thermometer; and a device that steams water (and has a steaming wand).
Some say only ice cold whole milk or homogenized can do true microfoam, but to that, I say "phhhhft". With enough care, technique and ability, you can steam almost any milk, even room temperature 1% milk* (*a caveat - while you can microfoam almost any milk, it is easier to steam ice cold, whole milk - has to do with a lot of chemical stuff I know nothing about)
Step 2 - Initial Preparation
Okay, you've got your machine, your milk, your steaming jug, your thermometer (later in your frothing years, you can do with out the thermometer, but for now keep it handy). Next, you want your machine heated up and putting out dry steam. What is dry steam? It's steam that, when you put your hand under it (not too close), very little water accumulates after 10-20 seconds - almost none at all.
So how do you do it? The following applies to any steaming device, be it stovetop, frothing only machines, steam toy espresso machines, or pump machines. Get the machine into steam mode (flip the switch, move the dial, turn the stove heat up), and bleed off any water coming through the wand as it heats up. Just let it pour into a cup or other vessel. Then as the steam comes out, and gets less wet, turn the valve off for a few seconds, turn on again, bleed off more wet steam. Eventually (after 10-40 seconds of this, depending on your machine), you should have nice dry steam.
Step 3 - The Little Things, Part 1
While you're "bleeding the wand dry" (stop reading stuff into this, willya?), your target is several things - dry steam, and LOTS of it. With steam toy espresso machines and pump machines (ones without dual boilers or heat exchangers) there is a further trick - don't let the steam lamp go off (or on, whatever indicates the boiler is not heating any longer). Making sure that boiler is always active means that while you continue to draw off steam, the machine is heating up the liquids inside to continually produce more steam.
Step 4 - Lock and Load Baybee, Here We Go!
Okay, so you've got dry steam, you've got tons of steam, and you've filled your pitcher 1/3rd full or less with milk, right? Next thing to do is to drop your steaming wand just to below the surface of your milk and let loose - start steaming! For the first few seconds (roughly 20 on cheaper machines or stovetop devices, maybe 5-10 seconds on more powerful machines) you want to hover the tip of the steamwand just at the surface of the milk so you get a deep and rapid rumbling sound - the sound of milk being foamed. During this first stage, you should be generating about half your total foam volume - set that as your target, along with a 100F temperature by this point. Remember to always lower the pitcher as you steam to keep that tip right near the visible surface - this is called "stretching the milk".
Also during this first stage, your foam might be "big bubbled" (don't let them get too big - if they are, lower the wand). As your technique improves you'll be able to minimize the "big bubble" effects, but for now, we'll say it's gonna happen: later on in this page, I'll explain how you'll do stuff to micro-size those bubbles. If your steam is especially powerful, be careful or you'll have milk everywhere.
Step 5 - Second Stage
Once you've done the initial frothing action and reached 100F, start lowering your wand into the milk. In fact, during this stage, you're going to be raising, lowering, and dancing your wand gracefully in the pitcher. This is the key to getting true microfoam - by dancing the wand in the pitcher, in the milk, you turn any "big" bubbles into air, and condense other bubbles into microbubbles. The temperature is still rising during this action, and you'll notice at around 130F, your foam is again rising in the pitcher. By the time you hit about 145F, it should be near the top of your pitcher, if not overflowing.
Step 6 - Finish and Pour, Quick!
Critical time, folks. If everything was done correctly, you'll be hitting 155F, the magic number for steamed milk and you'll have lots of foam. If you did it exactly right, you'll have microfoam that is so small, you can pour the contents of your pitcher without spooning the foam - because the sign of great foam/froth/steamed milk is foam/froth/steamed milk that can be poured without a spoon. Why pour quickly? Well if you did it right, why not move to the next stage - go for some latte art technique! You can only do latte art with microfoam, perfectly steamed milk, and you can only do latte art if you pour it right away.