Volantino

SCIENTIFIC EXPERIMENT: FROM CREAM TO BUTTER The purpose of this experiment is to understand that food can often be transformed into other food through different, often simple, processes. TOOLS: • 250 ml of fresh cream for desserts (cold) • 1 empty 1 litre clear plastic bottle • Scissors or knife • Tea towel • Fork • 2 bowls Pour the fresh cream into an empty clear plastic bottle to better observe the transformations and close it with the cap (make sure it is tightly closed). Vigorously shake the bottle until you perceive that the consistency inside has changed, the cream is now whipped. Continue shaking until you get two parts, one liquid and one solid. Open the bottle and empty the buttermilk (i.e. the liquid by-product of the transformation of cream into butter) into a bowl. Cut the bottle (with the help of an adult) and extract the solid part, the butter . Cover the bowl with the tea towel and place the obtained butter on the tea cloth. Now work the butter with a fork so that all the buttermilk comes out. Try tasting the obtained butter and describe its flavour. After shaking, a small pack of butter forms inside the bottle. By shaking vigorously, the cream will initially tend to whip producing what is called an emulsion. The emulsion consists in the dispersion of liquid drops inside another liquid in which they are totally, or almost, insoluble and therefore cannot dissolve. By continuing to shake, the fat globules in the cream break down, freeing the fat molecules. The latter are hydrophobic, meaning they do not like contact with water and tend to bond with each other to exclude it. The aggregation of the fat globules creates the butter, which will remain in the bottle, together with the buttermilk. PROCEDURE: WHAT CAN WE OBSERVE? THE WIDE WORLD OF MILK AND ITS DERIVATIVES LET’S EAT WELL 53