What is an Erlenmeyer Flask?
An Erlenmeyer flask and test tubes are the most iconic of lab glassware and are routinely associated with a science milieu on TV and in movies. Its conical shape and narrow neck are its distinguishing features. The rimmed mouth acts as a lip for easy pouring and long neck allows for airtight storage when used with a stopper. These features make them useful both in the lab and as novel kitchenware.
The key benefit to using a cork or rubber stoppered flask is the reduction or elimination of evaporation of stored liquids & contamination by airborne bacterial, fungal and chemical contaminants. For this reason, they are popular with chemists & biologists for storing chemicals or preparing algal or microbial cultures.
This advantage extends beyond the realm of science labs to home or work. The wide range of Erlenmeyer flask sizes enhances their versatility. From the very small 50ml for holding truffle oil, 250ml for salad dressings, 500ml for coffee cream and 1000ml (1L or roughly 1 quart) for juice or milk. All can poured spill free and autoclaved if necessary for long term storage.
Cork, Rubber or Other Stoppers
A common question is which is better, cork or rubber? Rubber will provide a better seal but cork has better aesthetic appeal, especially when used with consumables such as juices. Either are effective so it really comes down to personal choice.
Big Erlenmeyer Flasks
For large volume sizes such as 2, 5 & 10 litre, cork or rubber stoppers may not be readily available. Cellophane plastic wrap works well for airtight seals. Aluminum foil is popular with biologists when autoclaving (pressure cooking) since expanding gases can vent while still maintaining a sterile environment.
The great utility of Erlenmeyer flasks make them popular as promotional items by science equipment and chemical suppliers but also beverage makers. Some examples are shown below, all with a single color logo. Multicolor is possible but is very expensive and is usually done only on larger sized flasks.