What happens when you overheat butter is the butter will melt completely and then separate into fat and milk solids and even burn and result in a bitter taste.
When melting butter or cooking with butter it's important to watch it closely to ensure it's not overheating.
Butter has a smoke point of around 350 F which is low and means that the butter can burn easily if heated too long.
Melted butter is good for health in moderation, especially if you eat real butter made from dairy.
However all butter can be unhealthy when consumed in excess and can lead to heart disease, high cholesterol, increased risk of a stroke, heart attack, blood clots etc.
But when consumed in moderated the melted butter including non melted butter is okay for your health as part of a healthy and balanced diet.
It is OK to eat butter on bread in moderation although eating too much butter on bread or butter in general could lead to high cholesterol and heart disease.
But when consumed in moderation butter on bread or butter on toast or eating butter on other foods can be healthy.
Melted butter in bread makes the bread more flavorful, softer and richer and also provides the bread with a smooth and pleasant mouthfeel.
The melted butter in bread tenderizes the bread dough and softens the bread dough as well by limiting the development of gluten.
The melted butter also adds aroma and flavor to the bread and the kind of butter used in the bread dough can impact the flavor of the bread.
Melted butter in bread also glazes the bread crust as the melted butter melts into the crust of the bread and adds flavor and also makes the bread even more appealing visually.
The melted butter in the bread also makes for a more plush, softer and pillowy texture to the bread.
Melted butter also is added to bread as a spread and can be added to the dough with a spatula.
It is OK to eat melted butter as melted butter is just butter that has been changed into a liquid by melting it.
As long as the melted butter is not contaminated or spoiled it's safe to eat the melted butter although it should be consumed in moderation as part of a healthy balanced diet.
Melted butter is often used in baking and cooking and on bread and as a topping for pancakes, popcorn vegetables etc.
Melted butter does go rancid and even non melted butter does eventually go rancid especially when left out at room temperature or a long time.
Exposure to heat, oxygen and light can accelerate the oxidation process of the melted butter and non melted butter and cause it to develop an off flavor and turn rancid.
Oxidation of the butter is when the fats in the butter break down when they're exposed to air and cause it to go rancid.
Melted butter and other butter often goes rancid within a few days if not refrigerated.
The white stuff in melted butter is simply milk solids that are made of fat and milk proteins.
Butter is made of water, fat and protein that form an emulsion and when the butter melts the emulsion then separates into layers.
And the white foam which floats to the top is made of milk proteins and the white stuff or solids that settle to the bottom of the melted butter is just milk solids.
Butter melting including on bread is not a chemical change and is instead a physical change.
The butter melting including on bread is a physical change and not a chemical change because the butter is simply changing from the state of being a solid to the state of being a liquid.
And the chemical composition of the melted butter still remains the same.
This means that the butter that is melted can be reversed by cooling the butter back down to a solid state.
Toasting bread causes a chemical change known as the Maillard reaction and spreading and melting butter on warm toast is a physical change that is related to state transition.
When butter is heated up, the emulsion then separates and the fat also separates from the water which forms 2 layers.
The separated fat layer is also commonly known as ghee which is clarified butter.
Ghee and butter have different properties though and you cannot extract butter from ghee so that is a chemical change.
Melting anything including butter is a physical change as it changes the state of matter from a solid to a liquid.
And during the melting process the chemical composition of the substance doesn't change.
When an ice cube for example melts, it's still water and the chemical composition of the water is H2O.