I’ve been answering a few questions on Quora.com where you can find my profile! Check out this post or some of my other answers!
Answer by PurelyCoffeeBeans.com:
The coffee made in a brewer (like a drip coffee maker, espresso machine, Keurig) is used to extract the liquid. The coffee powder left isn’t like instant coffee. It can’t be dissolved by the hot water because the grains are too big for that (though Starbucks seems to have perfected micro-grinding for its own Via coffee), and won’t be included in your drink so your drink doesn’t taste ‘gritty’. This is normal.
If you want to try gritty coffee, just order a jug of French press when you’re in a restaurant, once you drink it, you can then pour the last of the coffee from the jug, you’ll see solids in your coffee… and they will taste a little bitter/gritty. They’re not bad for you, they just taste bad…
You can use the coffee grounds to fertilize your garden by composting them… BTW Keurigs are very wasteful of the caps you use, unless you recycle the caps/coffee.
There are several coffee shops around my house, and I have seen farmers coming by to collect used espresso grounds for composting! What do you do with the old coffee grains? Do you throw, compost, recycle or reuse?