The biēm has a patent-pending nozzle design that's designed not to clog. Here’s how it works: It takes the butter it melts through it's reservoir and sends it to the nozzle, where it emerges as a single separate butter stream. Air, not flammable propellants, from another stream, then atomizes it as it meets the butter stream and converts it into a spray.
Most sprays send the product and the propellant, (in many cases propellant that is flammable and will catch fire if used near flames), through the same path. What happens is, any foreign object that gets in that path can be too large and clog the nozzle. We separated that path into two isolated streams where we push butter through one and air (the biēm's propellant) through the other, thus allowing the pathway to remain open when some foreign matter gets in. Conventional old-fashioned "manual pump oil sprays" have this problem and can clog with just a spec of pepper, while the biēm does not.