How to Make Better Espresso at Home: Freshness, Grind Size and Extraction (Part 3)

You've chosen your coffee beans, warmed up your espresso machine and prepared to make your morning coffee. But when you take that first sip, something isn't quite right.

Perhaps the espresso tastes too sour, the bitterness is overwhelming, or the coffee lacks the sweetness you expected.

The good news is that you don't necessarily need a new machine or more expensive equipment to improve your espresso. Small adjustments to your coffee, grind size and brewing recipe can make a noticeable difference.

At Boardwalk Coffee, we believe great coffee starts with good beans, but how you prepare them matters too.

Here's how to get more from your coffee and make better espresso at home.

1. Start with fresh coffee beans

Freshness is an important part of making good espresso.

After roasting, coffee beans gradually release carbon dioxide and lose some of the aromatic compounds that contribute to their flavour. This process continues over time, so how you store and use your coffee can affect the cup.

However, freshly roasted coffee isn't always ready to brew immediately.

Coffee often benefits from a resting period after roasting, allowing some of the carbon dioxide to escape. If you use beans too soon, the gas released during extraction can affect how water moves through the coffee and make it harder to achieve a consistent result.

The ideal resting period depends on the coffee, roast profile and your brewing setup.

How can you tell whether your coffee is fresh?

When buying coffee, look for a clear roast date rather than relying only on a best-before date.

The roast date tells you when the coffee was roasted, helping you understand how long it has been resting.

You should also pay attention to the packaging. Coffee benefits from protection against excessive exposure to air, moisture, heat and light.

At Boardwalk Coffee, we roast in small batches at our roastery in Youghal, County Cork, and include the actual roast date on our coffee bags.

This makes it easier to understand the freshness of the coffee you're buying.

How should you store coffee beans?

Once you've opened your coffee bag, keep the beans in an airtight container in a cool, dry place away from direct sunlight.

Avoid storing coffee next to an oven or another source of heat, and keep it away from moisture.

It's generally best to avoid storing everyday coffee supplies in the fridge, where moisture and odours can become a problem.

If you buy larger quantities, consider dividing the coffee into smaller portions so you're not repeatedly exposing the entire supply to air.

The key takeaway: Buy coffee with a clear roast date, store it carefully and give it enough time to rest after roasting.

For more information, read Boardwalk's existing article about coffee freshness and why roast dates matter.

2. Get your espresso grind size right

Grind size is one of the most important variables when preparing espresso.

Espresso machines force water through a compact bed of finely ground coffee. The size of the coffee particles affects how easily water flows through that bed and how quickly flavour compounds are extracted.

If your grind is too coarse, water may flow through too quickly. If it's too fine, water may flow too slowly.

Both can affect the balance of the finished espresso.

What should espresso grounds look like?

Espresso generally requires a fine grind, but there isn't one universal setting that works for every coffee and machine.

Different beans behave differently, and even changing to a new bag of the same coffee may mean making a small adjustment.

Your grinder's numbered settings are also not standardised. A setting on one grinder may produce a very different result on another.

Rather than looking for a specific number, use the behaviour and taste of your espresso to guide you.

How to adjust your grind size

If your espresso runs too quickly and tastes sharp or underdeveloped, try grinding slightly finer.

If it runs very slowly and tastes harsh or excessively bitter, try grinding slightly coarser.

These are useful starting points rather than absolute rules. Sourness and bitterness can have several causes, so consider the overall flavour before making adjustments.

Make small changes and pull another shot.

Changing the grind gradually will help you understand how your coffee responds.

3. Understand espresso dose and yield

Once your grind size is close, the next step is to pay attention to how much coffee you use and how much espresso you produce.

The amount of dry coffee placed in the portafilter is called the dose.

The weight of the espresso produced is called the yield.

Together, these measurements help you create a repeatable brewing recipe.

What is a good espresso ratio?

A useful starting point for espresso is a ratio of approximately 1:2.

This means producing around two grams of espresso for every gram of dry coffee.

For example:

VariableStarting pointDry coffee dose18gEspresso yield36gExtraction timeApproximately 25–35 seconds

These figures are a starting point, not a strict definition of a good espresso.

Your machine, basket, coffee and personal preferences may call for a different dose, yield or extraction time.

Some coffees taste better with a shorter yield, while others benefit from a longer extraction.

The important thing is to start with a repeatable recipe and adjust it according to flavour.

Why use a scale?

A scale helps you measure your dose and yield accurately.

Without one, it's easy to produce a different amount of espresso each time, making it harder to identify what's changing the flavour.

You don't need expensive equipment to get started. A small digital scale capable of measuring in grams can make your brewing much more consistent.

Once you have a recipe that works, you can reproduce it more reliably.

4. Learn to recognise under-extracted and over-extracted espresso

Extraction describes the process of dissolving flavour compounds from ground coffee into water.

Getting the balance right is essential for producing espresso that tastes good.

Two common problems are under-extraction and over-extraction, although the flavours associated with them can overlap.

What does under-extracted espresso taste like?

Under-extracted espresso often tastes sour, sharp or underdeveloped.

You may notice that the coffee lacks sweetness or tastes thin and unbalanced.

This can happen when the water hasn't extracted enough of the coffee's soluble compounds.

Possible adjustments include grinding finer, increasing the yield or changing the brewing temperature if your machine allows it.

Make one adjustment at a time and taste the result.

What does over-extracted espresso taste like?

Over-extracted espresso can taste harsh, excessively bitter or drying.

However, bitterness isn't always caused by over-extraction. The roast profile, coffee variety and other brewing variables can also contribute.

If your espresso tastes unpleasantly bitter, consider whether your grind is too fine, your yield is too high or the coffee itself has pronounced roasted flavours.

Adjusting the recipe may help, but it's important not to assume that every bitter espresso has the same cause.

Let taste guide your adjustments

Extraction time is useful, but it isn't the only measure of quality.

A shot that takes 30 seconds isn't automatically better than one that takes 25 or 35 seconds.

The goal is to find a combination of grind size, dose and yield that produces balanced flavour with your particular coffee.

Taste the espresso, identify what you want to improve and make a small change.

Over time, you'll become more confident at recognising what works.

5. Keep your espresso machine clean

Coffee oils and old grounds can accumulate in your equipment, affecting the flavour of future shots.

Even if you're using excellent beans, a dirty portafilter or basket can introduce unwanted flavours.

Regular cleaning helps your coffee taste as intended and keeps your equipment working properly.

After each brewing session:

• Empty the portafilter and discard the used coffee grounds.
• Rinse the basket and portafilter.
• Wipe away coffee residue around the group head.
• Follow your machine manufacturer's instructions for regular cleaning and maintenance.

If your machine requires backflushing or periodic descaling, follow the manufacturer's guidance.

A clean machine provides a better starting point for understanding how your coffee tastes.

6. Make small changes rather than changing everything

When espresso doesn't taste right, it can be tempting to change the grind size, dose, yield and temperature all at once.

The problem is that you won't know which adjustment made the difference.

Instead, establish a basic recipe and change one variable at a time.

For example, if the espresso tastes sour and runs quickly, try grinding slightly finer while keeping the dose and target yield consistent.

Taste the next shot and see whether the balance improves.

If it doesn't, consider another small adjustment.

Keeping a few notes can also help. Record the coffee you're using, the grind setting, the dose, the yield and your impression of the flavour.

You don't need a complicated spreadsheet. Even a few observations can help you recognise patterns and reproduce a good result.

7. Choose coffee that suits your brewing style

Your technique matters, but the coffee itself also plays an important role.

Different coffees respond differently to espresso brewing, and their flavours can vary considerably.

If you enjoy chocolatey, rounded flavours, look for coffees with those characteristics in their tasting notes.

If you prefer bright acidity and fruity aromas, explore coffees with more expressive profiles.

Single-origin coffees can be particularly interesting because they allow you to discover the characteristics of individual coffees. Blends can also produce excellent espresso and may offer a more familiar flavour profile.

There isn't one type of bean that works best for everyone.

The important thing is to choose coffee you enjoy and then adjust your brewing recipe to suit it.

Discover better espresso with Boardwalk Coffee

Making better espresso doesn't have to involve complicated techniques or expensive equipment.

Start with good coffee, store it properly and use a consistent brewing recipe. From there, small adjustments to grind size and extraction can help you discover the flavours your coffee has to offer.

At Boardwalk Coffee, we roast speciality coffee in small batches in Youghal, County Cork, with a focus on quality and helping people discover great coffee.

Whether you're looking for a coffee to enjoy as a straight espresso or something that works beautifully in a flat white, exploring different beans is part of the experience.

Discover the Boardwalk Coffee online store and find your next coffee to try at home.

Then experiment with your brewing recipe, trust your palate and enjoy the process of making better coffee.

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