### Water, water everywhere: A study in texture

#### Overview of this Week's Science

##### Motivation: wouldn't it be awesome to deep-fry mayonnaise?

This was the question that Wylie overheard from an intoxicated guest at a dinner party, which led to a whole realm of culinary exploration. He wrote to the food science branch at the CIA to ask about recipes for deep-fried mayonnaise -- and got back the standard recipe for mayonnaise. He had to explain that he was a professional chef, and learned how to make mayonnaise on the first day. Eventually, he was put in touch with Ted Russin, who helped find new products that could make a heat-stable version of the condiment.

###### Some polymers are better than others for certain applications, depending on the sizes and shapes of their molecules.
• Xanthan gum is longer than starch, so it is a more effective thickener.
• Amylopectin is branched, so for the same molecular weight it is less effective than amylose.

#### Equation of the Week

###### You can calculate how the elasticity, E, of a material is related to its viscosity, η by a time constant, τ.

$$\eta = E \cdot \tau$$

Soft matter scientists use a special tool called a rheometer to quantify this relationship, but you can still see everyday applications of this. For instance, if you try stirring honey too fast, it feels like a solid, but if you slowly drag the spoon, then the honey can flow around like a liquid.

#### Beyond the lecture

Wylie thinks that edible shaving cream would be amazing. This could be a reserach project idea for future Science and Cooking students or enthusiastic home cooks.