When to Use a Bain Marie—or Hot-Water Bath—When Baking

When a recipe calls for a hot-water bath, it (unfortunately) is not an instruction for you to take a nice, relaxing soak while your dessert bakes. Also known as a bain marie, a hot-water bath is an essential technique for cooking creamy desserts in the oven to achieve smooth custards, fluffy cheesecakes, and flawless flans. To learn more about the classic French technique of bain marie and to glean tips for making it as fuss-free as possible, we asked Elise Bayard Franklin, a chef instructor at The Cambridge School of Culinary Arts in Cambridge, Mass., for a lesson on what a bain marie is and her tips to use it safely and efficiently.

What a Hot-Water Bath Is—and When to Use One

A hot-water bath is a gentle method of oven cooking whereby individual ramekins or a single pan (most commonly a springform pan) are set inside a large baking dish with high sides, such as a roasting pan, that is set in the oven. The pan is then filled with very hot water until it reaches halfway up the sides of the baking dishes. The result of using a water bath is a steamy environment in your oven that promotes even cooking for delicate foods like cheesecakes, flans, creme brûlées, and custards.

Bayard Franklin likes to think of a hot-water bath as an insurance policy for bakes that are prone to overcooking or cracking. "Baked custards are the dish I think of immediately when asked when to use a water bath", she says. "A baked custard, such as a cheesecake, is prone to cracking, but the moisture provided by a hot-water bath can help prevent that." The hot water bath also helps ensure a silky texture for creamy, custard-like desserts.

Why It's Vital to Use Boiling Not Tap Water

When a recipe calls for a hot-water bath, it's tempting to use hot water from the tap but Bayard Franklin advises you to think twice about shortcuts and boil the water instead. "The idea with a water bath is to provide steam and protect your baked goods," she says, suggesting that you only pour just-boiled or simmering water into the pan and put it straight in the oven so it doesn't cool down too much.

The Best and Safest Way to Assemble a Water Bath

There's no getting around it that a hot-water bath can be challenging to assemble and transfer to the oven. You are, after all, potentially dealing with a handful of little custard-filled dishes, a cumbersome roasting pan, and a good amount of boiling water sloshing around. This is why it's useful to wait to pour in the water until your roasting pan is already situated in the oven.

Additionally, if you are using individual dishes like ramekins—rather than one large dish of cheesecake or flan—Bayard Franklin suggests not placing all of the ramekins in before adding the water so you can have an easier time pouring. "Pour slowly and from a low height," she says. "The ramekins will displace the water a bit, so be sure to account for that and use a little less water. That way, when you put in the last couple of dishes, the water won't surpass about halfway up the sides."

How to Safely Handle After Baking

Bayard Franklin says the best way to transport your perfect pots de crème from the bain marie after they are cooked is by using a pair of tongs to lift the rim of each ramekin up and out of the roasting pan. "A wide offset spatula can also do the trick if you have room to get it into the water bath and under the dish," she says.

Now that you're feeling confident about using a hot-water bath, give the technique a spin with this seasonal recipe for Maple Flan.