What happens when coffee granules is mixed with warm water?

When coffee granules are mixed with warm water, several physical and chemical processes occur, resulting in the preparation of a cup of coffee. Here's what happens:

1. Dissolution: The warm water acts as a solvent, and the coffee granules begin to dissolve into it. The soluble components of the coffee, such as caffeine, flavors, and aroma compounds, start to diffuse throughout the water, creating a mixture.

2. Extraction: The warm water also extracts various compounds from the coffee granules. This includes caffeine, which is a stimulant and gives coffee its characteristic kick. Other compounds, such as flavor molecules and oils, also get released, contributing to the taste and aroma of the coffee.

3. Diffusion: As the coffee granules dissolve, the coffee solutes spread out evenly throughout the water through diffusion. This process ensures that the concentration of coffee components is uniform throughout the beverage.

4. Filtration (optional): Depending on the brewing method, filtration may be used to separate the coffee grounds from the extracted coffee liquid. When using a pour-over coffee maker or a French press, a filter paper or a metal mesh screen is used to trap the coffee grounds while allowing the liquid to pass through.

5. Chemical reactions: The warm water interacts with the coffee grounds, resulting in some chemical reactions. For example, the acids present in the coffee can react with the minerals in the water, which may slightly alter the flavor of the coffee.

The end result of this process is a flavorful and aromatic cup of coffee, ready to be enjoyed. Adjustments can be made to the coffee-to-water ratio, brewing temperature, and brewing time to customize the strength and flavor of the coffee.