Make your espresso or strongly brewed coffee: If you don’t have an espresso machine or pod option like a Nespresso, strong French press or double-strength brewed coffee are good options.
To froth the milk without a frother: Pour the milk into a large jar with a lid. Ideally, fill no more than a third of the jar. Screw the lid on tightly, and shake the jar vigorously until the milk is frothy and has roughly doubled in volume. This should take 30 to 60 seconds.
Remove the lid and microwave the milk, uncovered, for 30 seconds. The foamy milk will rise to the top, and the heat from the microwave will stabilize it. Keep an eye on the jar. If you see the foam is close to overflowing (it will actually climb an inch or more above the top of the jar before spilling over), stop the microwave, let the foam settle a bit, and then restart to finish the 30 seconds, stopping again, if necessary, to allow the foam to settle. If the milk is not warm enough after the first 30 seconds, give it another 30 seconds, keeping your eye on the jar, once again, to avoid overflow.
Pour the espresso or strong coffee into a wide, shallow coffee cup or mug of choice. Pour the desired amount of warm milk over the espresso. The foam tends to cling to the jar, but you can hold it back with a spoon if necessary. If you’d like to add a flavored syrup or sweetener, stir it in now. Then use the spoon to scoop the foam on top. Garnish with a sprinkle of cocoa powder or cinnamon if desired.
