Cold foam is three ingredients and thirty seconds. Heavy cream, a splash of 2% milk, and vanilla syrup frothed until it’s thick enough to sit on top of your drink without immediately sinking — that’s the whole thing. The Starbucks version costs between $1 and $1.50 as an add-on. The homemade version costs pennies and takes less time than standing in line.

And if you’ve been through the McDonald’s drive-thru since May 2026, you already know cold foam isn’t just for coffee anymore. Their Dirty Dr Pepper — Dr Pepper with vanilla syrup and a cloud of cold foam — is exactly what it sounds like and it’s genuinely good. The homemade version is better, costs less, and you can make it in your kitchen without leaving the house. Recipe for that is below.

First, the technique — because the reason most homemade cold foam fails isn’t the frother. It’s either the wrong dairy ratio or frothing past the right stopping point.

Why the Dairy Ratio Matters

Heavy cream alone frothed into a beverage topping produces whipped cream — stiff, dense, and too thick to pour or spread evenly. Milk alone doesn’t have enough fat to hold the air that frothing introduces, so it stays loose and collapses quickly. The combination is what creates cold foam: enough fat from the heavy cream to trap air bubbles and hold their shape, enough liquid from the milk to keep the texture pourable and light.

The Starbucks ratio for vanilla sweet cream cold foam is roughly 2 parts heavy cream to 1 part 2% milk. At home, that’s about 2 tablespoons heavy cream and 1 tablespoon 2% milk per serving. Scale up if you want a thicker layer or you’re making drinks for more than one person.

The Vanilla Syrup

Store-bought vanilla simple syrup — Torani, Monin, or the Starbucks vanilla syrup sold at grocery stores — is the fastest option. About half a teaspoon per serving is the standard.

Homemade vanilla simple syrup: combine equal parts sugar and water in a small saucepan, heat until sugar dissolves, remove from heat, stir in half a teaspoon of vanilla extract per cup of syrup, cool completely. Keeps in the refrigerator for up to two weeks. Made once, it covers two weeks of daily cold foam.

Vanilla extract used directly in the foam instead of syrup works but adds less sweetness and doesn’t distribute as evenly. If you use extract, add a tiny pinch of powdered sugar to compensate.

How to Froth It

Handheld frother: add the heavy cream, milk, and vanilla syrup to a small jar or cup. Hold the frother just below the surface and run it for 15 to 20 seconds, moving it slowly up and down. Stop when the foam is thick enough to coat the back of a spoon but still loose enough to pour.

Mason jar: add all three ingredients, seal the lid tight, and shake vigorously for 30 to 45 seconds until thickened. Takes more effort than a frother and the foam is slightly coarser, but it works with zero special equipment.

Blender: works well for larger batches. Blend on medium for 15 to 20 seconds. Don’t over-blend — too long and you’ll cross into whipped cream territory.

What Done Looks Like

This is the step most recipes skip and the reason most homemade cold foam disappoints. You’re looking for three things: it should pour slowly (not run off a spoon like liquid), it should hold a soft shape for a few seconds when you stop pouring (not collapse instantly), and it should be noticeably thicker than the starting liquid without being stiff or lumpy.

Too thin and it sinks right into the drink: froth longer. Stiff and lumpy and won’t pour: too far — add a splash more milk and gently stir to loosen.

Putting It on the Drink

Pour cold foam over the back of a spoon held just above the surface of the drink. This slows the pour and helps the foam land on top rather than plunging through ice. Don’t stir — the foam sits on top and slowly incorporates as you drink. That layered experience is the whole point.

The Homemade Dirty Dr Pepper

McDonald’s launched their Dirty Dr Pepper in May 2026 — Dr Pepper with vanilla syrup and cold foam — and it’s been driving traffic to every dirty soda conversation online since. I’m personally addicted to these and the homemade version is the one I make at least three times a week.

Here’s how to do it at home: Fill a glass with ice. Pour in a can of Dr Pepper — or grab a fountain Dr Pepper if you have access to one, which is better. Add half a teaspoon of vanilla syrup directly to the soda and give it one gentle stir. Make your cold foam using the recipe above. Pour the foam slowly over the back of a spoon onto the top of the Dr Pepper. Drink immediately.

The cold foam and vanilla against the Dr Pepper’s 23 flavors is exactly as good as it sounds. The cream softens the carbonation slightly and the vanilla pulls out a sweetness that’s always been there but suddenly more present. It tastes like a Dr Pepper Cream Soda with a cloud on top.

For a slightly different direction: swap the vanilla syrup for coconut syrup and add a squeeze of lime to the soda before topping with plain cold foam. That’s the Utah-style dirty soda version that’s been driving the trend on social media for years before McDonald’s got there.

Cold Foam on Other Drinks

Cold brew and iced black coffee are the classic applications — the foam provides sweetness and creaminess without diluting the coffee. It also works on iced matcha lattes, iced chai, and any cold drink where you want a creamy topping that isn’t whipped cream.

Beyond coffee and Dr Pepper, cold foam works on any soda you’d call a dirty soda. Sprite with vanilla cold foam. Coke with salted caramel cold foam. Orange soda with plain cream foam for a creamsicle effect. The technique is the same regardless of what’s underneath.

Flavor Variations for the Foam

Brown sugar cold foam: substitute brown sugar simple syrup for vanilla syrup. Pairs especially well with cold brew and Dr Pepper.

Cinnamon cold foam: add a pinch of ground cinnamon to the mixture before frothing. Distribute evenly so it incorporates into the foam.

Salted caramel cold foam: substitute caramel syrup and add a tiny pinch of flaky salt. Excellent on iced espresso and on a Coke.

Coconut cold foam: substitute coconut syrup. Pairs well with Dr Pepper, pineapple soda, and cold brew.

Dairy-Free Version

Full-fat coconut cream is the best dairy-free substitute for heavy cream — it has enough fat to hold foam. Barista-edition oat milk (Oatly Barista) replaces the 2% milk and produces better foam than regular oat milk because of the higher fat content and added emulsifiers. The foam is slightly less stable but holds up long enough to enjoy.

Storage

Make foam fresh each time — it starts separating back into liquid within a few minutes. The vanilla syrup, however, can be made in a larger batch and refrigerated for two weeks. Having syrup ready makes the daily process even faster.

If you’re building out your homemade drink collection, the Copycat Orange Julius Mix — thisoldbaker.com/copycat-orange-julius-mix and the Base Milkshake Mix — thisoldbaker.com/base-milkshake-mix-no-ice-cream-required are both worth keeping in the pantry alongside this one.

Frequently Asked Questions