What happens to brewed coffee as it gets older in the pot?

As brewed coffee sits in the pot, it undergoes several changes that affect its flavor and quality:

1. Oxidation:

* Oxygen: Coffee is exposed to oxygen in the air, which causes oxidation. This process breaks down the aromatic compounds responsible for coffee's flavor and aroma, leading to a stale and flat taste.

* Loss of Flavor: The more oxygen it's exposed to, the more flavor is lost. This is why freshly brewed coffee tastes much better than coffee that has been sitting out for a while.

2. Cooling:

* Temperature: As coffee cools down, it loses its volatile compounds, which contribute to its aroma and flavor.

* Flavor Shift: This can lead to a less intense and less appealing flavor profile.

3. Bacterial Growth:

* Bacteria: While not a major concern for short periods, prolonged exposure to room temperature can allow bacteria to grow in the coffee. This can create an unpleasant taste and potentially make you sick.

4. Chemical Reactions:

* Coffee Components: The various components in coffee react with each other, resulting in a change in taste and texture. The bitterness may increase, and the coffee might become less acidic.

How to Keep Coffee Fresh:

* Brew Small Batches: Only brew as much coffee as you will drink immediately.

* Keep it Hot: Keep the coffee hot with a warming plate or carafe.

* Refrigerate: For later consumption, store leftover coffee in an airtight container in the refrigerator. It will last for a few days, but the flavor will be diminished.

In short, brewed coffee doesn't "go bad" in the same way that milk does, but its flavor and quality deteriorate rapidly over time. For the best taste, enjoy your coffee fresh!