Flask, Conical (Erlenmeyer)

Quick Answer: An Erlenmeyer flask is a conical laboratory flask with a flat base, straight sloping sides and a narrow cylindrical neck. Named after the German chemist Emil Erlenmeyer, it is used for mixing by swirling, heating and holding solutions, recrystallisation and growing liquid cultures.

Why the Erlenmeyer Shape Has Lasted

Emil Erlenmeyer introduced the conical flask in the 1860s, and its geometry has changed little since. The wide base gives a large heating surface and a low centre of gravity, the sloping walls redirect a swirled liquid inwards, and the narrow neck limits evaporation and can be closed with a bung, a cotton-wool plug or foil. Together these make it the default container in chemistry and microbiology laboratories for tasks that combine mixing with a moderate amount of heat.

In recrystallisation, for example, a hot saturated solution cools more slowly and loses less solvent from this conical shape than from a beaker, and the crystals that form can then be collected by suction filtration. In microbiology the same shape carries broth cultures on a shaker platform, where the sloping walls keep the medium moving without spilling.

The listing does not state capacity, glass type or whether the neck is plain, beaded or fitted with a ground joint. If a set of several sizes is wanted in one order, see the assorted conical flask set.

Specifications

Applications

• Recrystallising crude organic solids such as benzoic acid or acetanilide from hot water or ethanol
• Preparing and sterilising culture media, with the neck closed by a cotton-wool or foam plug
• Growing bacterial or yeast cultures in liquid broth on a shaker
• Collecting a filtrate or distillate where a narrow neck reduces evaporation
• Titrations in college analytical chemistry practicals

Care & Handling

• Heat the flask on a hot plate or over a gauze and swirl the liquid from time to time; never heat an empty flask.
• When autoclaving, cover the neck with a loose plug or foil so steam can enter and pressure cannot build.
• Clean the inside of the shoulder, where residues collect out of reach, with a curved flask brush.
• Hold a hot flask by the neck with tongs or a heat-resistant glove, not bare fingers.

Why Choose LabEquip

College chemistry departments, microbiology labs and school preparation rooms get through conical flasks faster than most glassware because the flask serves so many tasks. They are stocked with LabEquip’s chemistry lab equipment; tell us the sizes, neck type and quantities on the contact page.

Frequently Asked Questions

Is an Erlenmeyer flask the same as a conical flask?

Yes. The two names describe the same flat-based, cone-shaped design. Some catalogues use conical flask for school listings and Erlenmeyer for college or microbiology listings, but the shape is identical.

Why is a conical flask better than a beaker for recrystallisation?

The narrow neck reduces solvent loss and cooling from the surface, so the hot solution stays saturated and cools slowly, which favours larger, purer crystals. The shape also makes it easy to swirl while adding hot solvent a little at a time.

Can this flask be used under vacuum?

No. Standard conical flasks have relatively thin walls and a flat base, which can fail under a pressure difference. Suction filtration needs a heavy-walled filtering flask with a side arm, which is built for that purpose.

How should the neck be closed for autoclaving media?

Use a cotton-wool or foam plug, or a loose foil cap, so steam can reach the medium and air can escape. Never autoclave a flask closed with a tight bung or screw cap, as pressure inside can crack the glass.

Is this flask suitable for liquid cultures?

Yes. The flat base sits steadily on a shaker platform, and the narrow neck takes a cotton-wool or foam plug that lets air in while keeping dust and airborne microbes out. Baffled versions, with indentations in the base, improve aeration further where needed.

Can the flask go directly on a hot plate?

Glass flasks can generally be heated on a hot plate if the glass type suits it and the plate is warmed gradually. Confirm the glass type, and keep the flask no more than about half full so boiling liquid cannot climb the neck.

Last Updated: September 2026