Filtration - Solid-Liquid Filtering

The video explains the process of making fresh coffee, focusing on the role of filtration. It describes how coffee grounds are mixed with hot water, leading to a solution where flavor and color particles dissolve, but the grounds remain insoluble. Historically, coffee drinkers faced the issue of grounds in their drink until Melita Benz invented the paper coffee filter in the early 1900s. This invention allowed water to pass through while retaining the grounds, revolutionizing coffee preparation. The video concludes by emphasizing the significance of filtration in modern coffee making.

What is the primary reason coffee grounds do not dissolve in water?

• They are too large.

• They are insoluble.

• They are too hot.

• They are too dense.

Who invented the modern paper coffee filter?

• Melita Benz

• Thomas Edison

• Marie Curie

• Albert Einstein

What problem did Melita Benz aim to solve with her invention?

• Coffee was too bitter.

• Coffee grounds were getting into drinks.

• Coffee was too weak.

• Coffee was too expensive.

How did Melita Benz create the first coffee filter?

• By using a plastic sheet.

• By using paper from a school notebook.

• By using a cloth.

• By using a metal sieve.

What is the main function of a filter in the context of coffee making?

• To add flavor to the coffee.

• To allow liquid to pass while holding back solids.

• To cool down the coffee.

• To heat the coffee.