All About Double Boilers
A double boiler as produced and marketed by the cookware industry is a very specialized piece of cooking equipment. A commercially produced double boiler consists of a basic two-or three quart straight-sided sauce pan and another insert pan that has a slightly rounded bottom and fits snugly into the top of the bottom pan.
Often, a double boiler set will come with a lid. Never use the lid—if you ever use the bottom pan alone, feel free to use the lid, but most foods that need to be cooked in a double boiler require constant stirring.
Now comes the question: do you really need to purchase a specialized pan set?
The answer is no. A double boiler can easily be rigged at home. All you need is a deep and wide pan and a large glass or metal bowl whose bottom will fit down in the pan. If the pan is too small or the bowl is too big, the heat will be concentrated right at the very bottom of the bowl. You want as much of the bowl to be inside the pan as possible to promote even heat distribution. (see photo)
As far as I’m concerned, a home-made double boiler is works better than a store-bought set. Often, the bottom of the insert is a little flat on the bottom but with rounded sides that then have a rim that has been pressed into the pan. This little rim is what keeps the insert from falling down into the bottom pan. It’s also a place where food can get stuck.
The shape of these pans is not very conducive to whisking, and whisking is what you generally do in a double boiler. So, skip the store-bought version and make your own double boiler using a whisk-friendly metal or glass bowl for the top.
Do You Need A Double Boiler?
Now that you know what a double boiler is and that you can make your own, let’s spend a minute talking about why you need one and how to use one. Honestly, there are not many times in a home kitchen that you will need a double boiler to prepare your day to day recipes.
There are times, though, when you want to melt chocolate or make a pastry cream or lemon curd that a double boiler comes in handy. A double boiler provides gentle, indirect heat to whatever you are cooking.
Rather than the heat of a burner transferring directly to the food, the heat is transferred to the water in the bottom pan and then through steam. The steam bathes the bottom of the double boiler in very even gentle heat that can easily be controlled on a home stove—just move the pot off of the heat if the water starts boiling vigorously.
My Version of a Double Boiler Using a Pasta Pot & Stainless Mixing Bowl
How to Use a Double Boiler
To use a double boiler correctly, put about 1 to 2 inches of water in the bottom pan, and put the pan on the stove on medium heat. Make sure that the bottom of the top pan will not be touching the water when it is inserted into the bottom pan.
Then, place the top pan on the bottom pan and add your ingredients. Whisk the ingredients constantly and control the heat so that the water maintains a simmer, not a vigorous boil.
A notable exception to this technique is in melting chocolate. To melt chocolate without scorching it, place chopped chocolate in the top of a double boiler, bring the water to a boil and then turn the heat off. Let the gentle heat melt the chocolate, stirring occasionally to make sure it melts evenly.
When melting chocolate, be very careful that no water gets in the top pan. If this happens, the chocolate will seize into a lumpy, grainy mess. You will still be able to use it in recipes, but if you were planning on tempering the chocolate, you won’t be able to.
Since water and chocolate really do not get along, I no longer advise melting chocolate over a double boiler but rather in a microwave in a glass bowl using short bursts at medium power and stirring between bursts.
When to Use a Double Boiler
Recipes that most often call for the use of a double boiler include all custards (pastry cream, pudding, sabayon, zabaglione, etc) as well as lemon curd and delicate emulsions like Hollandaise sauce. While some of these recipes can be prepared over direct heat, using a double boiler keeps the heat more even and gentle and can prevent scorching.
The ability to deliver gentle heat is the main advantage to using a double boiler. Most of the disadvantages arise from buying specialized equipment: storage issues, buying a one-trick pony, expense. These disadvantages do not apply if you use a bowl and a pot that you already own to create your own double boiler.
Don’t Forget About Bain Maries
“Wait! What about bain maries?”
A bain marie is similar to a double boiler as both deliver more gentle heat to whatever you are cooking. They do differ in some ways, though.
When using a double boiler (bought or made), you don’t want the water level to come up to the bottom of the top pan—the heat is transferred completely by steam. Double boilers are also used on the stove top.
A bain marie, or water bath, is used in oven baking to protect delicate egg-based foods from overheating and curdling. When using a bain marie, or water bath, the pan/pans holding the food are placed into a larger pan.
This pan is then carefully filled with hot water, usually about halfway up the side of cooking vessel. The entire setup is often covered with foil.
The bain marie provides moist and gentle heating to egg-based foods. Since the cooking vessels are placed directly in the hot water, as long as the water level remains constant, the temperature delivered from the sides never exceeds 212 degrees F (at sea level). This ensures even, gentle cooking and guards against curdling, which is what happens when eggs cook too fast or in too harsh an environment.
To confuse things a bit farther, often cooks in professional kitchens place metal cylinders of soup or sauce into larger pots of hot or boiling water. These cylinders are called “bains.” Even though this is a stove top method, since the hot water comes in direct contact with the cooking vessel, this is considered a bain marie as opposed to a double boiler.