11 Common Mistakes You Probably Make When Brewing Coffee

Crafting a perfect cup of coffee at home is actually easier than it seems. Nonetheless, there are some common mistakes that we can avoid, in order to improve and refine our coffee-making skills.

Let’s learn the fundamentals of brewing while addressing 11 of the most common mistakes that homebrewers make.

1. Not Using Fresh Coffee Beans and Grounds

Most of us are guilty of using coffee beans that have been hanging about in our kitchen cupboard for several months. In fact, the shelf life of coffee beans is a mere 4-5 weeks.

Our pro-tip is to purchase small bags of coffee beans each time, and stay away from store-bought beans. These beans often have an expiry date of 12-24 months, which is way past their shelf life.

For greater convenience, consider signing up for a coffee subscription service which delivers freshly roasted beans to your doorstep at your preferred frequency.

2. Pre-grinding Coffee

coffee being grounded into a white cup
Ground coffee beans just before brewing to ensure that your coffee is packed with flavours. Photo from Noora AlHammadi.

Did you know that coffee starts to lose its flavour the moment it is ground? With its physical compounds broken down, it is exposed to moisture and air that cause it to go stale.

The optimum shelf life of pre-ground coffee is only one week. Therefore, to ensure that your brew is fresh, invest in a coffee grinder so that you can prepare your grounds quickly and simply whenever you need a caffeine fix.

3. Using the Wrong Grind Size

A one-size-fits-all approach doesn’t apply to coffee grinding. Depending on your brewing method, the ideal grind size ranges from fine to coarse.

Using the right grind size ensures that your brew is neither too sour nor bitter, due to under or over extraction.

Here’s an infographic for you to find out which grind size is best for your brewing method.

4. Not Storing Your Coffee Beans Properly

beans in an opened container
A vacuum-sealed or airtight container will preserve the freshness of coffee beans. Featuring the De’Longhi Vacuum Coffee Canister. Photo from De’Longhi.

This is one of the most common yet disastrous mistakes that many make – tying up an opened coffee bean bag with a rubber band. No matter how tight the knot, aroma will escape while air will find a way to enter the bag.

Your coffee beans’ greatest enemies are air, moisture, heat, and light. Without storing beans in an opaque vacuum-sealed or airtight container, the freshness of beans will be compromised as they lose their flavour and aroma profile.

5. Choosing the Wrong Coffee Roast for Your Brew Method

There are three main categories of coffee bean roasts – light, medium, and dark. Each roast has its unique characteristics, with the lighter roast having a mild taste and the darker roast carrying a robust yet pleasant note.

Pairing the roast with the right brewing method will make or break your coffee. Here’s a general guide on which roast is ideal for the most common brewing methods.

an infographic listing the best roast for various brewing methods
Match the right coffee roast to your brewing method for the perfect marriage of flavours.

6. Using Tap Water

The water that you use to brew coffee matters. Tap water has many minerals that are detrimental to the extraction and flavour of your coffee.

The recommended pH level of water for brewing is between 6.5 and 7.5 to ensure that your coffee is well-balanced. If it is a hassle to get bottled water within this pH level, the best alternative is to run tap water through a filtering system or use a filter pitcher.

7. Using Freshly Boiled Water

Many homebrewers make the common mistake of pouring freshly boiled water over coffee grounds. That’s a big no-no.

The high temperature will cause the grounds to extract its flavours too quickly, resulting in a bitter brew. Conversely, cold water will lead to under-extraction and a sour brew as flavours are extracted too slowly.

The ideal temperature for water is slightly below the boiling point at 90-96 degrees. A simple tip is to let freshly boiled water rest for about 1.5 to 2 minutes.

8. Not Tamping Your Grounds with the Right Pressure

a heap of coffee grounds in a portafilter
Apply an optimum pressure to compact coffee grounds for the perfect extraction. Photo from David Lundgren.

Tamping is a key part of making a perfect shot of espresso. A pressure of approximately 19-20kg will create a bed of grounds with even density to ensure a consistent flavour extraction.

However, homebrews make the common mistake of applying an inconsistent tamping pressure or getting an imperfect coffee puck.

Before tamping, give the portafilter a quick tap on the table, then apply firm pressure on the coffee grounds while keeping the tamper perfectly level with the table.

9. Under or Over Extracting

There are a multitude of factors that result in under or over extraction. But one of the ost common factors is getting the brewing time wrong.

When you don’t brew your coffee for long enough, there isn’t sufficient time for the water’s heat to bring out the complex flavours of the bean to balance the acidity present in it. That results in under extraction.

Likewise, if the brew time is too long, over extraction occurs as bitter chemicals from coffee grounds are continually released.

In addition, to spot an under-extracted or over-extracted coffee, pay attention to its colour. This infographic shows it all.

10. Reheating Your Coffee

a blue reusable coffee cup by De'Longhi
With a good reusable coffee cup, your coffee stays hot for hours. Featuring the De’Longhi x STTOKE Ceramic Reusable Cup. Photo from De’Longhi.

Once a cup of coffee turns cold, there’s no turning back. Reheating affects the chemical makeup of your brew and ruins the flavour profile.

If you are a slow coffee drinker, invest in a double-walled coffee cup as it keeps your drink hot longer than a single-walled cup. Before deciding on which reusable coffee cup to buy, here are some things you should consider.

This sleek, shatterproof and lightweight reusable cup has captured the hearts of those who enjoy the finest cup of coffee.

11. Not Cleaning Your Coffee Machine Frequently

When was the last time you descaled your coffee machine? If it’s been more than 3-4 months, it’s time to get it cleaned.

Descaling is a metal cleaning process that removes the buildup of limescale; a hard, off-white, chalky deposit that can impair the operation of your coffee machine, and more importantly, affect the taste of your coffee.

To ensure your brewing equipment is clean, regular descaling is a must. Here’s a step-by-step guide to get you started.

Now that you know the common mistakes to avoid, there’s nothing stopping you from crafting the perfect brew!