How to Brew Espresso

What You'll Need

Equipment:

An Espresso Grinder
An Espresso Machine
Espresso Puck Preparation tools
Scale
Timer

Recipe Overview:

Brew Ratio: 1:2 (Ground Coffee to Espresso)
Grind: Fine
Dose: 18g
Yield: 36g
Water Temperature: 96°C
Total Brew Time: 30-35 seconds

Advised Methods

Step 1: Measure and Grind Coffee

Dose: 18 - 20 grams

Grind Size: Fine

Brew ratio: 1:2 grams of espresso to brew liquid

Yield: 36 - 40 grams

Every espresso machine is different, and every basket behaves a little differently. Use these numbers as your starting point, then adjust to suit your setup and taste.

Your portafilter basket should comfortably hold 18g of coffee. Most baskets are rated by capacity, with a small tolerance of around ±2g.

Overfilling the basket can compact the coffee too tightly, restricting water flow and leading to uneven extraction. If your shot runs slowly, resist grinding coarser straight away—first make sure you're using the correct dose for your basket.

A well-balanced espresso should pour 36–40g in approximately 25–30 seconds, delivering sweetness, body and clarity in the cup.

A clean puck makes a cleaner shot.

Before tamping, take a moment to level, distribute and remove clumps. Water will always follow the easiest path, so an uneven puck can lead to channeling, weak extraction and an unbalanced espresso.

Paper Filter-> Place a portafilter paper at the bottom of the basket.
Distribute-> Use a WDT tool to break up clumps and evenly spread the grounds.
Tamp-> Tamp level and firm with around 20 kgs of pressure.
Puck Screen-> Place a puck screen on top for a cleaner, more even extraction.

Step 3: Tamp

A consistent tamp creates a consistent extraction.

Once your grounds are evenly distributed, tamp with a level, firm pressure of around 20 kgs. Avoid twisting the tamper—press straight down for a flat, even puck.

If you're using a puck screen, place it on top of the coffee after tamping.

Gently insert your portafilter into the group head and rotate until it locks into place.

Secure it firmly, but don't overtighten—this helps protect the group head gasket and ensures a consistent seal.

Place your cup on a set of scales on the drip tray.

Step 5: Pull the Shot

Yield- 36–40g

Time- 30–35 sec

Most machines will have a double espresso button. However, if there is a lever (Rocket or Fracino) to initiate extraction, pull half way out in order to build the require amount of pressure (9 Bar).

Most machines include a short pre-infusion before the coffee begins to flow. Once extraction starts, aim for a smooth, steady stream until you reach 36–40g in around 30–35 seconds.

If your shot reaches the target weight too quickly, your grind is likely too coarse. Adjust your grinder slightly finer in order to avoid under-extracted, sour flavours and try again.

If your shot takes longer than 35 seconds you should grind coarser to avoid over-extracted, bitter flavours.

Remember, taste comes first. Swirl your espresso, take a sip, then make small adjustments until you find the sweet spot.

If you want to turn your espresso into a flat white, cappuccino or latte with confidence. Use our Espresso Drink Calculator to find the ideal espresso-to-milk ratio for every drink.

Dial in. Taste. Repeat.

Frequently asked questions

A good espresso is all about balance. Visually, your espresso grinds should look almost like confectionary sugar, but the real test, if you ground correctly, will be running it through your espresso machine. Use these signs to fine-tune your grind:

Too Coarse

Shot finishes in under 30 seconds.
Espresso pours fast with little resistance.
Thin crema.
Tastes sour, sharp or watery.

Too Fine

Shot takes over 35 seconds.
Slow drips or choking.
Dark, overly thick crema.
Tastes bitter, dry or harsh

Just Right

36–40g of espresso in 30–35 seconds.
Smooth, steady flow (like warm honey).
Rich, even crema.
Sweet, balanced and full of flavour.

Set your grinder to your starting grind size (this will vary based on roast).
Purge a small amount of coffee to clear any grounds from the previous setting.
Grind 18g of coffee and check the weight. Adjust your grinder timer if needed to hit your target dose.
Prepare your puck consistently using your usual workflow and an even, firm tamp (around 20 kgs of pressure).
Pull your shot using our recipe (36–40g in 30–35 seconds).
Taste and adjust.
- Shot too fast? Grind finer.
- Shot too slow? Grind coarser.
Purge, grind and repeat after every adjustment until your shot is balanced and tasting great.

Single Basket

Holds 7–10g of coffee.
Produces one espresso shot.
More difficult to dial in consistently due to the basket shape.
Best for those wanting a smaller espresso.

Double Basket

Holds 16–20g of coffee (we recommend 18g).
Produces a double espresso.
Easier to extract evenly and far more forgiving.
The preferred choice for most home baristas and cafés.

Our Recommendation

At Cold Start, we recommend using a double basket with 18g of coffee. It's easier to dial in, delivers a more balanced extraction, and gives you the perfect base for espresso, flat whites, cappuccinos and lattes.

Puck preparation is the process of preparing your ground coffee before brewing. The goal is to create a level, evenly distributed coffee bed so water flows through the puck evenly.

A well-prepared puck helps prevent channelling, where water finds the easiest path through the coffee, leading to an uneven and under-extracted shot.

A good puck preparation routine includes:

Dosing the correct amount of coffee.
Breaking up clumps with a WDT tool.
Evenly distributing the grounds.
Tamping level with firm, consistent pressure.
(Optional) Adding a puck screen before brewing.

Not really.

Once the coffee is fully compressed, applying extra pressure has very little effect on extraction. What's more important is that your tamp is level and consistent every time.

Problems are usually caused by an uneven tamp, not a hard one.

An uneven puck can cause water to flow through one side faster than the other, leading to channeling and an unbalanced espresso.