beaker stopperAt Macalaster Bicknell Company of New Jersey, we specialize in manufacturing glass tubing, rods and scientific glass. Our products are used in chemistry labs, to make blown glass art pieces, and everything in-between. But if you’re looking for glass containers to store chemicals or solutions, we also offer an array of beaker stoppers.

Beaker Stoppers

A beaker stopper is also known as a laboratory rubber stopper or rubber bung. It’s most often used in chemical laboratory applications in combinations with flasks, test tubes and serum bottles. However, a beaker stopper is also crucial for the fermentation process in wine making.

The size of a beaker stopper varies among approximately 16 standard sizes, each of which are specific to a certain type of container. Even the material of the stopper can range depending on application. For example, green neoprene has great chemical resistance, which is ideal for storing chemical solutions. But for food fermentation, a beaker stopper should be made of white natural gum. Even the temperature can affect what kind of material a beaker stopper should be made of. For very high temps, red or white silicone should be used.

Additionally, a beaker stopper can feature one or more holes for plugging depending on application. But above all, to prevent liquid or chemical leaks, a beaker stopper should fit snugly to the container’s opening.


At Macalaster Bicknell, we offer stoppers for 1mL and 5mL serum bottles. We also offer a 20mm slotted stopper. The all-purpose design is great for lyophilization applications because it reduces the possibility of the two legs sticking together.

For almost 70 years, Macalaster Bicknell has been a preferred source of high tech glass supplies in the United States. We offer a variety of glass products, including tubing, glass blanks, flasks, bottles and rods. But we also offer glass and laboratory accessories, like beaker stoppers, lab coats and stirring bars. For all your high tech glass needs, contact Macalaster Bicknell today.