A few, such as water, are called Newtonian fluids because their behavior is actually quite similar to what Newton described. However, the real world is not quite that elegant, and every fluid is different. The more viscous the fluid, the more it resists moving. The complexities of viscosity come in when different forces are applied: stirring, swirling, scooping.īack in 1686, Sir Isaac Newton mathematically described the physics of viscosity in his usual elegant way, giving an equation that approximates how a fluid moves when a force is applied to it. On the ramp, your nacho cheese sauce or what-have-you is just moving downhill, propelled by the steady force of gravity. Fill the compartment with your fluid foodstuff of choice, then open the gate and let it flow down the ramp! The distance it flows in 30 seconds is a measure of its consistency, rather than its viscosity, which is a related but more complicated phenomenon. The Bostwick Consistometer is a foot-long metal ramp with a ruler along its length and a gated compartment at the top. But-as with many kitchen phenomena-when you look closely, there’s a lot more to it. Viscosity is a characteristic of fluids, and it’s (deceptively) easy to get a handle on intuitively: honey is more viscous than water, and olive oil is somewhere between the two. Then viscosity was suggested as a Word of the Week by a reader, and I did a little reading and found myself in the thick of it.

Paul, Do You Know the Difference Between Consistency and Viscosity? read one subject line, and I thought, sure I do. I recently subscribed to an entertaining email newsletter for users of the Bostwick Consistometer texture measuring device. Get ready to impress at your next cocktail party. We’ll be sharing many of these fun words with you in this ongoing series, the Cook’s Illustrated Word of the Week. Working at the intersection of food and science, we come across a LOT of scientific jargon and terminology, from chemical processes, to physical phenomena, to species names.

The line test for viscosity