If your morning cup of coffee has been tasting a little off lately, or if your trusty drip coffee maker is taking forever to finish brewing a full pot, you probably do not need to run out and buy a new machine. The solution is almost always much simpler and cheaper than a trip to the appliance store. Your coffee maker is likely suffering from a buildup of something you cannot see but is definitely there: mineral scale.

Think of your coffee maker’s internal water lines and heating element like the inside of a teakettle. Over time, the minerals naturally found in tap water, especially calcium and magnesium, solidify and form a hard, chalky deposit. This is scale. In a kettle, you might notice white flakes floating in your water. In a coffee maker, this buildup clogs the tiny tubes and coats the heating element. The machine has to work harder to push water through, and that element has to burn more energy to heat up. The result is a pot of coffee that brews slower, at a lower temperature, and often tastes bitter or flat because the water is not hot enough to properly extract flavor from the grounds. The good news is that fixing this is a straightforward DIY project that will take less than an hour of your active time, and it can extend the life of your appliance by years.

The process is called descaling, and while you can buy fancy commercial descaling solutions at the grocery store, your kitchen pantry likely already holds the perfect ingredient: plain white vinegar. Vinegar is a mild acid that dissolves mineral deposits effectively. It is safe, non-toxic, and very inexpensive. To start, remove the paper filter and any leftover coffee grounds from the basket. Rinse the carafe well. Fill the water reservoir halfway with equal parts white vinegar and cold water. Place the empty carafe back on the warming plate, and then start a normal brew cycle. About halfway through the cycle, when about half the vinegar-water mixture has dripped into the carafe, turn the machine off. Let it sit for about thirty minutes. This soak time is critical because it gives the vinegar time to work on the stubborn scale sitting deep inside the machine. After the sit, turn the machine back on and let it finish the brew cycle. When it is done, pour the hot liquid down the sink. You will likely see some discolored water or small white flecks in the carafe. That is the scale coming loose.

Now, you need to rinse the machine thoroughly to get rid of any vinegar taste or smell. Fill the water reservoir all the way to the top line with fresh, cold water. Run a full, complete brew cycle with nothing but water and an empty carafe. You will want to repeat this fresh water cycle at least two more times, using a full tank of water each time. This step is important. If you skip it, your next pot of coffee might have a faint hint of pickles. Once you have run three full cycles of fresh water, your machine is clean and ready to go. Brew a full pot of coffee. You will almost certainly notice it finishes faster than before and the coffee tastes cleaner and hotter.

How often should you do this? That depends on your water hardness and how much coffee you drink. A good rule of thumb for most homeowners is to descale every three to six months. If you use very hard well water, you might need to do it every two months. An easy reminder is to descale your machine when you change your clocks for daylight saving time. For maintenance between deep cleans, consider using filtered water in your machine. This will dramatically slow down the rate of scale buildup and keep your coffee tasting great week after week. Taking the time to descale your drip coffee maker is a simple act of care that pays off in better flavor and a longer-lasting appliance.