Burrs for coffee grinders can be found inside your grinders. They grind your coffee beans to your liking and are an important part of the coffee-making process. Burrs, as opposed to blades, which can also be used to grind coffee, are prefered by many because they create a more uniformed size output. Users have more control over the grinding process, which allows for more versatility. Many people wonder how often they should replace their coffee grinder burrs; burrs should be replaced at least once or twice a year. By replacing them, the coffee's freshness and flavour are preserved. If the burrs aren't changed on a regular basis, the coffee can taste sour or bitter, among other things. Another clue that it's time to replace it is if the amount of coffee grounds it produces starts to clump together within. If you don't change your burr, your coffee machine's overall performance may suffer. Coffee grinders can become clogged, and the blades can become dull or broken. When this happens, it will be pricey because two parts will need to be replaced. Keep track of when you last changed your burrs so you can establish a schedule for replacing them.