Milk frother gadget costs $14 and tops iced coffee in 30s

A handheld frother is basically a tiny whisk on a motor. It looks and works a lot like a stick blender: you pour milk into a glass, dip the head in, and hold the button down until the foam is as thick as you like.

The model in question is the Zulay Kitchen frother, which runs on disposable AA batteries. With fresh batteries it reaches a good texture in roughly 30 seconds to a minute. As the cells run down, the motor slows and the job takes longer. That slowdown is actually useful: if you find yourself waiting and getting impatient, it is your cue to swap in new batteries.

There is no heating, no pitcher to wash and nothing to plug in. Rinse the whisk head under the tap and it goes back in the drawer.

The drink that sold one home barista on the frother was a cream top: an iced Americano with vanilla cream floated on top, tasted at a small cafe in Los Angeles’ Koreatown. The goal at home was to copy it.

The cream top traces back to the Einspänner, a Viennese espresso drink whose name refers to a carriage pulled by a single horse. In the original hot version, whipped cream sat on top like a lid and helped keep the coffee warm for drivers working in the cold. The idea later took off in South Korea, where cafes made all sorts of mostly iced variations, and from there it reached the US, where Starbucks’ cold foam drinks had already made people comfortable with foam on cold coffee.

What makes a cream top different is the texture. It sits between airy latte foam and dense whipped cream, so it melts and drips slowly into the coffee instead of staying on top like a hat or vanishing in seconds.

Lower fat milk usually gives you more foam. Food scientist and dietitian Jennifer Pallian explains that frothing traps air bubbles inside a thin film of water and protein, and nonfat milk carries more protein relative to fat, so it tends to produce a bigger, steadier foam than richer milk does.

A simple routine looks like this:

• Pour about half a cup of cold nonfat milk into a glass.
• Froth for around 30 seconds, until it is thick.
• Let it rest for a minute so it firms up, then spoon it over your drink.

For a sweeter, richer cream top, mix some heavy cream and a little vanilla syrup into the nonfat milk before frothing. Caramel syrup works the same way.

Your coffee needs enough flavor to stand up to the foam. Without an espresso machine, concentrated cold brew does the job, and some recipes suggest powdered espresso instead. One favorite experiment was a copy of a Starbucks ad: cold brew with coconut ube cold foam, dusted with toasted coconut flakes.

Plant milks can be trickier. Almond and oat milk have weaker protein and fat structures, so they can struggle to hold a stable foam, although barista blends made for frothing tend to behave better.

For most people the case for a cheap frother is simple. It costs about the same as a couple of cafe drinks, it works with coffee you can make in bulk, and it lets you control the sugar and the milk in every cup.

Cold foam can also be the lighter choice. A serving of Starbucks cold foam has 35 calories and no fat, compared with 60 calories and 6 grams of fat for a serving of its whipped cream. The trade-off is flavor: fat carries taste, so cold foam feels lighter and a little less rich than a cream topping.

The frother is not a one-trick tool, either. It blends hot chocolate without lumps, whisks eggs, and stirs creatine or protein powder into a shake.

You can spend far more than $14, and some people should. Countertop frothers are jugs with a spinning whisk inside and a heating base underneath. They can make hot foam for cappuccinos as well as cold foam, and some offer several foam levels and temperatures at the touch of a button.

That convenience has costs. One tested countertop model, the Instant Pot 9-in-1, made thick, steady foam from both whole milk and oat milk, but a batch of extra hot foam took about three minutes, longer than the coffee itself. Its heated base also left some residue in the pitcher after a couple of rounds, which needs washing.

If you mostly drink iced coffee and want foam on top, the handheld wand is the better value. If you drink hot lattes every morning or make drinks for a family, a heated jug starts to make sense.

You also don’t need a gadget at all to try it first. Shaking nonfat milk hard in a mason jar that is only half full will foam it, and pumping a French press plunger up and down works too. A hand blender can do it, but it tends to leave bigger bubbles.