5 reasons why your coffee tastes bad

Here are 5 reasons why your espresso coffee may not taste as good as it should and what to do to fix it.

About a week after your coffee is roasted, the de-gas process will have settled and your coffee will be ready to brew.

An espresso coffee should have full body, have a crisp brightness and a subtle sweetness with some bitterness.

It shouldn't taste overly bitter, sour or have a metallic taste.

There are numerous factors at play when creating a great tasting coffee. Firstly, the beans have got to be of a high quality and a medium roast profile works well for espresso. If you are experiencing some unpleasant tastes when making espresso, then read on: 

1. Over extracted - Too much bitterness and a long, unpleasant and lingering aftertaste usually indicate that the coffee is over-extracted. If the coffee takes too long to come through the group handle, it will burn the coffee. The problem is usually that the grind is too fine. Adjust your grinder or get your coffee roaster to adjust it for you.

The metal blades in the grinder must come very close to each other the finer it grinds, therefore the blades will heat up during this process and a metallic taste can be a result.  Espresso grind is fine but not too fine - it is an exact science.

Also please don't over extract in order to get more coffee because extracting too much coffee from a single dose will not taste good. If you want a stronger tasting coffee use a double basket and keep the shot length the same - 25 to 30 seconds.

2. Under extracted - too much sour acidity is a sign of under-extraction . If the coffee is extracted too quickly through the group handle it will have very little flavour and body. The espresso will look watery and have little to no crema. The problem is usually that the grind is too coarse. Adjust your grinder or get your coffee roaster to adjust it for you.

3. Not tamping evenly or firmly - an uneven tamp, is where the coffee surface is uneven or not enough pressure has been applied to the coffee puck. Use the right size tamper for your filterholder basket (tampers come in different sizes). There is no need to buy the top of the range, most expensive tamper on the market, if used correctly even a plastic tamp will produce good results. Ensure the filterholder is supported on a stable surface and press down firmly and ensure that your compressed coffee puck is flat and even. Then wipe any excess coffee grounds from the rim of your filterholder basket.

4. Dirty equipment - coffee oils and milk will "bake" onto the hot parts of the espresso machine. Just take a moment to think about how that 'burnt' coffee oil residue that builds up over time would taste. Yuck!

Regular cleaning procedures can minimise the build up. Take a look at our previous post for some tips on cleaning your espresso equipment.

And remember to regularly rinse (or replace) your coffee cloths.

5. Leaving coffee in the filterholder basket - leaving spent coffee in the basket will not only make you unpopular with the next user, but it will increase the build up of coffee oils and grime inside the coffee group and filterholder. This just means you'll need to clean it more often.

Dump out the coffee puck into the coffee waste bin, place your filterholder into the espresso machine and flush some fresh hot water through it. Flushing an empty filterholder with fresh water will remove the majority of spent coffee oils from the grouphead, shower screen, filter basket, and the filterholder.

In summary,

• slow flowing extraction indicates too fine a grind, too much coffee, or too much compression on the coffee puck.
• fast flowing extraction indicates too coarse a grind, not enough ground coffee, or not enough compression on the coffee puck.
• a very light under-extracted crema can indicate a cold portafilter, insufficient extraction pressure, too little ground coffee, stale coffee, poor quality coffee blend, or cold cups.
• a very dark over-extracted crema or a thin patchy layer of crema can indicate too much pressure in extraction, too much ground coffee, a dirty grouphead shower screen, or the time to extract took too long.