It's an inexpensive reusable coffee filter that fits any Keurig-brand at-home coffee machine, so you can use it however many times you want without guilt or going to a coffee shop. And it's easy ...
The filter is definitely necessary ... If you're looking for the quickest option for coffee, a Keurig can't be beat. The cheapest models start around $50 and larger/newer versions go up from ...
If your Keurig has a water filter, take it out, otherwise it will become soaked with vinegar which could continue to impact the taste of your coffee long after you've finished cleaning.
There are numerous ways to prepare your morning cup of coffee to enjoy in your breakfast nook, but using a Keurig machine is one of the most popular (and easiest) ways to get that daily caffeine fix.