So, you are sitting there drinking a cup of coffee, and you’re getting near the bottom of the cup. You take a drink without paying too much attention, and you feel a little grit in your mouth. Almost like dirt or sand. What the heck is that?
What is sludge?
Well, it’s most likely sludge. Coffee sludge. What’s that? Well, it’s sludge, or it will be! You see, when you make coffee in a French Press, some sludge is inevitable.
The photo shows how coffee is brewed in a French Press. When you are brewing there will also be a lid on the coffee (to keep it warm) and a plunger built into the lid. When the coffee is finished brewing, you will push the plunger down, thus moving all the coffee grounds to the bottom of the Press. Then, you pour the coffee into your cup and drink it.
French Presses have screens in the plunger to screen those coffee grounds from entering the stuff you will be drinking. However, some grounds (particularly the very find grounds, or dust) will certainly slip past the screens, and end up in your coffee cup. You can’t avoid it.
When you are grinding your coffee, that is when you will minimize the sludge that ends up in your cup. You will need to grind the beans as fine as you can, but not so fine that they slip through the screens. To do this, you need a good grinder, a burr grinder. A good burr grinder, though, can set you back a minimum of $100 or so.
I exclusively brew my coffee in a French Press. I feel that there is no better coffee, at least none that I have tried. However, right now, I am only using a cheap blade grinder to grind my coffee beans. With a blade grinder it is virtually impossible to grind the beans evenly. Only a decent burr grinder can do that. So, with a blade grinder like I use, you will end up with some of the coffee ground to dust, and some that are still like small rocks. When you have uneven grinding like this, you will certainly have sludge in your cup.
There is one other thing that you can also use a fine strainer to pour your coffee through on it’s way to your cup.
Personally, I don’t mind the sludge. I just don’t drink the last sip of coffee, and it’s no big deal. If it is something that bothers you, then use a strainer, or get a better grinder. I may upgrade my grinder later, but as of now, it is not something that bothers me, so no rush.
Enjoy your coffee! Sludge and all!