The Science of Making Salad Dressing
We investigated two more liquids that don't mix -oil and vinegar. Making their own salad dressings helps to make connections between what happens in science lessons and things that they might encounter in daily life. They smelled and tasted salt, pepper, rosemary and oregano and decided according to personal preference how many pinches to add to their own personal recipes for salad dressing, from 0 if they didn't like it at all to as much as 4 pinches if they really liked it. Then we added oil. When we next added vinegar, they could see that the vinegar didn't mix with the oil. The vinegar, however, would mix with water. We talked about which liquids were more alike, and which were different, and decided that they fit into two categories. The mineral oil and vegetable oil were in one and the water, food coloring and vinegar were in another.sources:
