Bitterness

brianthebard

When I get coffee out it is often bitter tasting, why? I think I heard that it was because the water had hit boiling point and burned the coffee or something, but I've used boiling water in a french press or forgot about the stove top before and it wasn't very bitter. Is it a fresh ground versus pre-packed thing? (as in I'm using prepacked).

Gran Hermano

In my experience it could be many causes but most likely water that's too hot or coffee that's over extracted.
Can you see how the coffee is made? If it's a filter machine it's most likely left on a hot plate and 'stewed'.

brianthebard

Well at least one of the cases was a machine in a shop that grinds the beans for each cup (from what I could tell). So you pushed the coffee button, grinding happened, and coffee came out.

Mr Magnolia

Over-extraction is probably the biggest cause of that horrible bitter taste followed by crap old beans.

I was guilty of it myself only recently. Making espresso at home - I filled the basket and didn't use any sort of grooming, this is a distribution technique that spreads the ground coffee evenly across the basket after filling.

I was filling the basket and then tamping an uneven surface of coffee. Imagine tamping the unevenly filled basket (coffee higher in the middle than around the sides), after tamping it all looks fine but there is a higher compression of coffee in the middle of the puck than anywhere else in the basket.

As a result the water does not 'flow' through the puck evenly, instead it's channeled around the outside of the basket. The ground coffee around this channel gets over extracted leading to that bitter thin tasting espresso.

To resolve this I'm currently using what's called NESW Grooming, it basically just means running the heaped grinds around the top of the basket to the North, then East, then South, then Westerly fashion, moving any excess coffee out of the basket on the final motion. If anyone else has a better way of explaining this then bash away. There are other techniques too, I'll put them up as I learn to describe them better if anyone's interested.


The same basic principles apply to large filter machines although crap coffee may be more to blame for the poor taste.

RE*AC*TOR

The basic answer is that most places serving coffee "out" do a poor job of it.

Depending on the specific scenario it could be anything from badly roasted beans to incorrect pressure to dirty machinery to bad technique.