January 17, 2023 2 min read

You've invested in a new super stylish espresso machine that looks great in your kitchen only to find that your precious espresso shot has a sour and unpleasant taste.

Don’t panic! We’ve got some pro tips to fix this terrible coffee conundrum quickly and easily.

Brew ratio

A sour taste is caused by under-extraction. This is a problem in balancing the amount of ground coffee and the amount of water or brew ratio. If there’s not enough hot water in the mix, this results in sour, under-extracted coffee. The ratio we recommend is one part coffee to two parts water.

Grind Size

The other factor that affects extraction is the grind size. If you grind your coffee too coarsely, you will end up with espresso that pours too quickly, meaning that the coffee grounds are not exposed to the water for long enough to extract their full, rich flavour.

Check the manual on your coffee grinder to find out the correct setting for the grind size you need.

Also, it goes without saying that the quality of your grinder will influence how well your coffee grinds, whether you use a hand coffee grinder or electric grinder.

The Baratza Sette 30 is one of our favourite coffee grinders, and is suitable for basic and advanced coffee machines.


You can find out more about the coffee grinders we recommend for making espresso here.

Dirty Espresso Machine and Equipment

If dirt and oils are not removed with regular cleaning of your coffee machine, they will go rancid, affecting the taste of your coffee, making it taste sour or bitter and unpleasant. Keeping your machine clean with daily and weekly cleans and regular descaling is vital.

Check out our wide range of cleaning products to keep all your coffee equipment sparklingly clean and fresh.

Thinking About Upgrading Your Espresso Machine? 

Explore our full collection of espresso machines. The Sage Bambino Plus is a great choice to take your espresso to the next level.


A Sweet Shot of Coffee News

For more expert info and inspo for true coffee fans, sign up to receive updates. We’ll never send you spam; you’ll only ever receive the freshest news from the world of fresh-ground coffee. Sign up here.

Do you have your own coffee business? Set up a trade account today and benefit from discounts of up to 50% on leading coffee brands including BaratzaBrewistaBonavitaRhinoCafettoClever and Fellow.