A bar strainer is a gadget which is used to keep pulp, crushed ice, fruit pits, and other debris out of mixed drinks. It is specifically designed for making cocktails and similar beverages, and does not have many uses beyond the bar. Many cooking and beverage supply stores sell bar strainers, usually made from stainless steel so that they are easy to care for. In addition, stainless steel will not corrode when exposed to acidic substances like lemon juice, unlike other materials which can be used to make kitchenware.

The design of a bar strainer usually includes a long handle for gripping, attached to a flat paddle with prongs designed to hold it outside a glass. A coiled spring along the edge of the bar strainer keeps the bar strainer in position and also strains the fluid being poured through it. To use a bar strainer, a bartender holds it in place on the top of a mixing glass and upends the mixing glass over the glass that the drink will be served in. The drink is able to pour freely through the bar strainer, leaving detritus behind.

Several companies make bar strainers in different sizes to fit into different glasses. As a general rule, a bar strainer is used with a mixing glass or beverage tumbler. These glasses are often larger than serving glasses, leaving plenty of room for mixing a drink or multiple drinks. It is important that a bar strainer fit snugly into a glass, because if it does not, chunks may slip through into the drink. People who are setting up a bar may want to consider purchasing bar strainers and glasses at the same time so that they can check for fit. A bar strainer can also be used with a shaker.

Using a bar strainer will yield a drink with a more homogeneous appearance and texture, making it more pleasant to consume. Especially when shaken mixed drinks are being served, the bar strainer ensures that no shards of ice find their way into the final product, as the chunks can be unwelcome to the consumer. In a professional setting, a strainer is crucial, and most bartenders have several at their work stations to ensure that one is always available. At home, a bar strainer can make a big difference in the quality of the drinks being served.

In most cases, the coiled spring on a strainer is removable for cleaning. Many bar strainers are dishwasher safe, in which case the coil should be removed and put in with the silverware. Otherwise, the bar strainer should be taken apart to be washed with gentle soap and warm water, and the parts should be dried separately.