Edit: Thanks so much for the silver kind stranger!
Edit 2: And the others! You’ve made my day! Glad I dropped my biscuit in my tea and decided I needed answers
In: Chemistry
Hot stuff melts the fats of food quicker, and generally when a solid/liquid/gas is hot the molecules move faster and can break weaker bonds as heat energy moves to something else.
The biscuit is to weak to handle the high energy
Cookies are sugar and butter. Put butter and sugar in cold water and watch what happens. Then put it in the microwave.
Id say im 99% certain that its just faster molecules interact more with other molecules (of the cookies/biscuits) causing the liquid to be absorbed faster. Similarly how hot liquids dissolve sugar/salt faster than colder liquids.
Hot=faster and more interactions
I am not sure if its right, but since a good portion of the structural integrity of these treats comes from fat (butter or whatever oil uses) and they melt quickly in hot tea or coffee…
Because the fats within the cookie / biscuit (butter, oils, etc.) loosen with heat and create a melting affect. The cold water hardens the fat instead of melting, making it harder for the cookie to dissolve.
By hot liquid, you probably mean hot water. Water dissolves simple carbohydrates (sucrose being the most common sugar in a cookie; sucrose is a disaccharide, formed of two different sugar molecules joined together in a solid, covalent bond), which help the cookie stick together. Hot water dissolves them more readily (quicker) and at higher concentration (more sugar dissolved in a given volume of water) than does cold water. Keep in mind that this is not melting, which is a common misconception. Sugars do not melt in water – they dissolve. People think they melt because a higher temperature allows the sugar to dissolve faster and in greater amounts. Again, this is not melting.
Thinking of non-aqueous liquids, hot vegetable oil would probably cause a cookie to fall apart faster than cold vegetable oil as well, but because in this case the oil is dissolving the fats, which would be congealed and sticky in the cookie, helping it hold together as well. It’s a general rule that the solubility (amount you can dissolve, per volume of liquid) of a solid increases in a liquid as the temperature is increased, although some solids are not soluble in certain liquids at all. For example, table salt is not soluble in vegetable oil or mineral oil at all.
By hot liquid, you probably mean hot water. Water dissolves simple carbohydrates (sucrose being the most common sugar in a cookie; sucrose is a disaccharide, formed of two different sugar molecules joined together in a solid, covalent bond), which help the cookie stick together. Hot water dissolves them more readily (quicker) and at higher concentration (more sugar dissolved in a given volume of water) than does cold water. Keep in mind that this is not melting, which is a common misconception. Sugars do not melt in water – they dissolve. People think they melt because a higher temperature allows the sugar to dissolve faster and in greater amounts. Again, this is not melting.
Thinking of non-aqueous liquids, hot vegetable oil would probably cause a cookie to fall apart faster than cold vegetable oil as well, but because in this case the oil is dissolving the fats, which would be congealed and sticky in the cookie, helping it hold together as well. It’s a general rule that the solubility (amount you can dissolve, per volume of liquid) of a solid increases in a liquid as the temperature is increased, although some solids are not soluble in certain liquids at all. For example, table salt is not soluble in vegetable oil or mineral oil at all.
The fat (butter usually) in a biscuit or cookie melt with hot water, unsticking the other ingredients from each other
A cookie is a composite of 3 things: Carbohydrates (sugar and starch), Fat, and Protein. The carbohydrates are water soluble to varying degrees, and will dissolve faster in hotter water, because the faster-moving molecules are better able to rip the molecules of the carbohydrates apart. Fats are not water soluble, but warm liquids will soften them, making the cookie softer. Protein (from the egg and to a lesser extent, the gluten in from the flour) isn’t super water soluble, but it doesn’t contribute as much to the overall structure of the cookie as the fat and carbs do. So, hot liquids can compromise 2/3 elements of the cookie’s structure a lot faster than cold ones.
There is a lot of fat in pastry. Butter mostly. When you melt the fat you lose structural integrity. Heat melts fat.
Latest Answers