In this activity you will explore what thickens a cheese sauce and measure how the viscosity changes when you eliminate the different thickening agents, one at a time. These tiny droplets act like the particles when a liquid is made viscous. In cooking, this typically means tiny droplets of oil or molten fat dispersed in a watery solution. An emulsion is a mixture of two liquids that do not usually mix well. Another way to thicken a sauce is by creating an emulsion. This explains why a small amount of starch can have a big effect on viscosity.

Their volume then increases by a factor of about 30. When heated together with a liquid, starches absorb the liquid and expand.

The more particles-and the bigger the suspended particles-the more viscous the liquid is.Ĭooks have a variety of ways to make a sauce more viscous. When you pour a fluid with higher-viscosity, these particles bump into one another the watery part cannot simply run down but needs to elbow its way through the crowd of particles, dragging them along. This typically happens when enough particles are suspended in the fluid. The more viscous a fluid is, the more it resists flow due to internal friction.

Sauces cling to food and to our palates, but how do you get just the right thickness or stickiness? Scientists describe the thickness, or gooiness, of a fluid by its viscosity. With this science activity you can be a scientist, a cook and a crowd-pleaser all at the same time! The sauce has to be just the right texture, though, or your noodles are either swimming-or just one big glob! So how can you get just the right texture? Get ready to invite some friends over to taste test. There's nothing like your favorite comfort food after a long day, right? Maybe it's beef stew, a really great salad or many people's favorite-macaroni and cheese.

How to make a cheese sauce stove top