What are examples of physical changes in cooking?

Changes in State:

* Melting: Ice cream melting, chocolate melting, butter melting

* Freezing: Making ice cream, freezing leftovers, making popsicles

* Boiling: Water boiling, making pasta, steaming vegetables

* Condensation: Steam condensing on a lid during cooking, condensation forming on a cold glass

* Sublimation: Dry ice sublimating into gas (though this is not common in regular cooking)

Changes in Texture:

* Whipping: Cream being whipped into whipped cream, egg whites being whipped into meringue

* Kneading: Dough becoming elastic and smooth during kneading

* Stirring: Stirring ingredients together to create a smooth batter or sauce

* Chopping: Cutting vegetables into smaller pieces

* Grinding: Grinding coffee beans, grinding spices

Other Physical Changes:

* Mixing: Combining ingredients without chemical reactions (like mixing oil and vinegar in a salad dressing)

* Separating: Separating egg yolks from whites, skimming fat off a broth

* Dissolving: Dissolving sugar in water, dissolving salt in broth

* Evaporation: Water evaporating off pasta while cooking, the liquid evaporating from a sauce

Key Point:

The key to understanding if a change is physical is that the chemical composition of the substance remains the same. For example, when ice melts, it is still water (H2O), just in a different state.

Let me know if you'd like more examples or want to discuss specific cooking processes!