Mix a ¼ cup of baking soda with 1 liter of water and pour it into your coffee maker's water reservoir. Turn it on and let it run for a fresh, odor-free machine.
Some people choose to stop the machine halfway through to allow the cleaning solution to sit in the internal parts of the machine for up to 30 minutes before finishing the cycle.
Baking soda's alkaline (high pH) nature helps dissolve coffee oils and mineral scales, and its abrasiveness aids in physically removing any leftover buildup.
Since the oils present in coffee can't be washed away with water alone and letting them build up can lead to clogs, it’s best to clean the machine at least twice a month.
Make sure to use baking soda and not baking powder, as the latter contains extra ingredients such as cream of tartar and cornstarch that are likely to leave unpleasant residues.