Why Your Home Espresso Tastes Bitter, Sour or Weak—and How to Fix It

You’ve bought a good coffee machine, followed the instructions and used quality beans—yet the coffee still doesn’t taste like the flat white you order at your favourite Melbourne café.

The good news is that your machine may not be the problem.

At Degraves Espresso, we’ve spent decades making coffee in the heart of Melbourne. Most disappointing home espresso can be improved by changing just one variable: the grind, dose, extraction time or freshness of the coffee.

Here is how to identify what has gone wrong—and fix your next cup.

Start With This Espresso Recipe

Before changing anything, establish a reliable starting point:

18g of freshly ground coffee
36–40g of espresso in the cup
25–30-second extraction
Filtered water at approximately 93–95°C
A clean, dry filter basket

Think of this as your baseline rather than an unbreakable rule. Every grinder, machine and coffee behaves slightly differently.

If you would like to explore other brewing methods, read our guide to making great coffee at home.

If Your Coffee Tastes Sour or Sharp

A sour espresso often means the water has passed through the coffee too quickly and hasn’t extracted enough flavour.

You may also notice a thin body, pale crema or a shot that finishes in less than 25 seconds.

The first thing to try: adjust your grinder slightly finer.

Keep the coffee dose the same and test again. Small adjustments are best—moving too far can turn a fast, sour shot into a slow, bitter one.

If Your Coffee Tastes Bitter or Dry

Bitterness is often caused by over-extraction. The water is struggling to pass through coffee that has been ground too finely, drawing out dry and unpleasant flavours.

The shot may take longer than 30–35 seconds and appear to drip rather than flow.

The first thing to try: make the grind slightly coarser.

Also check that you aren’t overfilling the basket or tamping unevenly.

If Your Coffee Tastes Weak or Watery

Weak coffee can be caused by too little coffee, too much water, an overly coarse grind or beans that have lost their freshness.

Weighing both the ground coffee and the espresso in the cup is the simplest way to remove the guesswork. If you start with 18g of coffee, aim to stop the shot when you have approximately 36–40g of espresso.

Allowing the machine to continue pouring well beyond this point will dilute the drink and introduce less desirable flavours.

If the Espresso Is Good but the Milk Coffee Is Disappointing

Milk should complement the espresso, not bury it.

For a flat white or latte, texture the milk until it is glossy and silky, with very fine bubbles. Aim for approximately 60–65°C. Milk that becomes excessively hot can lose its natural sweetness and develop a cooked flavour.

For plant-based coffee, use a barista-style milk designed for steaming. City Lights Blend’s medium-dark roast and full body allow its hazelnut, malt and chocolate character to remain present through both dairy and plant-based milk.

Don’t Overlook Water and Cleaning

Coffee is mostly water, so heavily chlorinated or unpleasant-tasting water will affect the result. Fresh filtered water is usually the best starting point.

Old coffee oils can also make fresh coffee taste bitter or stale. Regularly clean the filter basket, group head, shower screen, grinder chute and steam wand according to the manufacturer’s instructions.

Use Beans Suited to the Way You Drink Coffee

Degraves Espresso’s City Lights Blend is made with premium 100% Arabica coffee and designed to produce a rich, balanced cup.

Expect an inviting hazelnut and malt aroma, a smooth chocolate finish and a touch of tart green apple that keeps the coffee lively. Its body makes it particularly well suited to espresso, flat whites, lattes and plant-based milk.

Change One Thing at a Time

The most important home-barista habit is also the simplest: only change one variable between coffees.

If the shot is sour, adjust the grind finer—but keep the dose the same. If it becomes too slow, move slightly coarser. After a few attempts, you will begin to recognise what your machine is telling you.

That is when making coffee at home stops feeling like guesswork and starts becoming a craft.

Ready to try again? Shop City Lights Blend 250g or choose the 1kg City Lights bag for your home or office.