A non-reactive bowl is a bowl made of a substance that won’t react chemically with the foods you place in it. Reactive bowls are often made of metal, or plastics that stain easily. Typical reactive metals include copper, cast iron and aluminum. When you add any high acid foods to these bowls — like lemon juice, most citrus fruits or tomato sauce — they may actually react with the metal in the bowls and impart a metallic taste to your foods. If you’re looking for a non-reactive bowl made of metal, you always want to look for stainless steel, since it tends to resist reaction with high acid foods.

You’ll note, for instance, that the bowl that comes with a stand mixer is usually a non-reactive metal bowl, made of stainless steel. Don’t bother with a stand mixer that has a more cheaply made aluminum bowl, since this will limit what you can make with the mixer. If you prefer plastic bowls, look for the type that boast “non-staining” abilities, or try the new silicone bowls since they won’t react. Virtually any glass or ceramic bowl is a non-reactive bowl, and won’t stain or mix metal chemicals with acidic ingredients. Consider glass or ceramic bowls for fruit salad, anything containing lemon juice, and anything containing tomato sauce.

Under some circumstances a non-reactive bowl will not serve you as well as a reactive bowl. For instance, many chefs prefer to use copper bowls to whip egg whites. The egg whites react with copper and create whipped egg whites that not only whip faster, but are also more firm and stable. Note that if your copper bowl is advertised as a non-reactive bowl, it usually has a stainless steel or other coating that will prevent this reaction.

In general, you can use any type of bowl to make most cakes and cookies. Their time in the bowl is generally so short that ingredients won’t have time to react with metals. However, glass, ceramic or stainless steel, or any non-reactive plastic bowl is still a better choice, especially if ingredients will sit for any length of time in the bowl. Always choose a non-reactive bowl for high acid ingredients. For example, don’t mix vinaigrette in an aluminum bowl.

Many recipes now call for ingredients to be made in a non-reactive bowl, but don’t think this means you have to add expensive new bowls to your home or ones that are heavily advertised as non-reactive. Any glass or ceramic bowl tends to work just fine, and companies like Pyrex® make plenty of inexpensive bowls. You will want to look for non-reactive cookware; choose stainless steel over cast iron, copper, or aluminum when you plan to cook acidic recipes. Furthermore don’t forget to keep a reactive copper bowl on hand if you like to make soufflés, mousses, angel food cake or lemon meringue pie.