Pulling a great espresso at home is one of the most satisfying skills a coffee lover can learn. It's also one of the most frustrating when it goes wrong. The good news is that almost every problem has a clear cause and a clear fix.

I've been helping people dial in their shots for more than 20 years, in cafés and in home kitchens. Here's how to read your shot, understand what's happening, and get it right.

What is extraction?

Extraction is the process of dissolving flavour from ground coffee into hot water. When it's balanced, you get sweetness, complexity and a clean finish.

  • Under-extracted coffee tastes sour, sharp and thin.
  • Over-extracted coffee tastes bitter, harsh and hollow.

Grind size, dose, water temperature, pressure and time all affect extraction. The secret is to change only one thing at a time, so you can see what's working.

What you'll need

  • A burr grinder. The most important piece of kit after the machine itself.
  • Digital scales that read to 0.1g, ideally with a built-in timer.
  • A measuring glass if you measure your shots by volume.
  • A tamper that fits your basket snugly.
  • A knock box for used pucks.
  • Cleaning gear: a group head brush, a clean cloth and espresso machine cleaning powder.
  • Freshly roasted beans, ideally one to four weeks after their roast date.

Know your machine

Most home machines, like those from Breville and Sunbeam, come with their shot buttons preset to about 30ml for a single and 60ml for a double. That's a sensible place to start. In fact, it's not far off what we teach in cafés.

Two other things are worth knowing about your machine:

  • Check your baskets. Many home machines come with two kinds of basket. Dual-wall, or pressurised, baskets are designed for pre-ground coffee and do some of the work for you. Single-wall baskets give you far better espresso with freshly ground beans, but they need a good grinder and proper dialling in. If you grind fresh, use the single-wall basket.
  • Check your basket size. Every basket is designed for a certain dose. Most home double baskets hold somewhere between 16g and 20g. Check your machine's manual, and dose to suit.

Your starting recipe

For a double shot:

  • Dose: whatever your double basket is designed for, usually 16–20g. Weigh it.
  • Yield: about 60ml in a measuring glass, crema included. If you'd rather weigh it, that's roughly 36–45g on a scale.
  • Time: about 28–32 seconds.

This is a starting point, not a rule. Taste, then adjust. Some coffees shine with a slightly longer shot, others with a shorter one.

Step by step: pulling the shot

  1. Heat up properly. Turn the machine on well before you need it, and let it reach full temperature. Some heavier machines need 20 minutes or more. Keep the handle locked in the group while it heats, so it warms too.
  2. Warm your cup with hot water from the machine.
  3. Flush the group for a couple of seconds to clear old coffee and stabilise the temperature.
  4. Dry the basket with a cloth. Water left in the basket causes uneven extraction.
  5. Grind and weigh your dose straight into the basket.
  6. Distribute the grounds evenly. A gentle tap on the side of the handle, or a simple distribution tool, levels the bed.
  7. Tamp level and firmly. Consistency matters more than force: the same firm pressure every time, with the tamper flat.
  8. Wipe the rim of the basket so the handle seals cleanly against the group.
  9. Lock in and start straight away. Letting the coffee sit against the hot group head starts cooking it before the water arrives.
  10. Time the shot and check the yield. Then taste it black.

Grind size is your most powerful lever

If your shot tastes sour or runs too fast, grind finer. If it tastes bitter or runs too slowly, grind coarser. On a good burr grinder, even a small adjustment can transform a shot.

That's why the grinder matters as much as the machine. Blade grinders chop coffee into uneven pieces, which makes even extraction almost impossible. A decent burr grinder, manual or electric, is one of the best investments you can make for better espresso at home.

One more tip: after you change the grind setting, run a few grams through before your next shot. Some old grounds stay inside the grinder, and they'll still be at the old setting.

Water temperature

The ideal brewing range is about 92–96°C. If your machine lets you adjust it, try around 93°C for lighter roasts and 91°C for darker ones. Water that's too hot pulls out bitterness. Water that's too cool leaves the shot sour.

Use filtered water if your tap water is hard. Espresso is around 90% water, so the water you use has a big impact on flavour, and hard water scales up your machine.

Reading your shot

Watch the flow. A well-extracted shot starts slowly, builds into a steady, honey-like stream, and finishes before it turns pale and watery.

  • It gushes straight away: the grind is too coarse or the dose is too low.
  • It barely drips: the grind is too fine or the dose is too high.
  • It sprays or flows unevenly: you're probably getting channelling, where water rushes through the easiest path instead of the whole puck. Check your distribution and tamp.

Always taste the shot black before adding milk. You can't diagnose extraction through a flat white.

Common problems and fixes

  • Sour, sharp or thin: under-extracted. Grind finer, increase the dose slightly or raise the temperature a little.
  • Bitter, harsh or hollow: over-extracted. Grind coarser, reduce the dose slightly or lower the temperature a little.
  • Channelling: improve your distribution and tamping, and dry the basket before dosing.
  • Little or no crema: the beans are probably stale. Check the roast date, and see our guide to batch numbers and best-before dates.
  • Too much crema, and the shot tastes sharp: the beans may be too fresh. Give them a few more days to rest.
  • Different results every day: weigh your dose every time, and keep your beans sealed and stored well.

Keep a simple log

Jot down your dose, yield, time, grind setting and how it tasted. After a week, you'll see patterns, and when you open a new bag, you'll know exactly where to start.

Keep it clean

Old coffee oils build up fast and turn every shot bitter.

  • After every use: knock out the puck, rinse the basket and handle, and flush the group.
  • Weekly: brush the group head and, if your machine allows it, backflush with cleaning powder using a blind basket. Check your manual first, as not every home machine is designed to be backflushed.
  • Regularly: descale according to your machine's instructions, especially if your water is hard. Brush out your grinder too.

Start with great coffee

Even perfect technique can't rescue stale beans. Start with freshly roasted coffee, store it properly and grind just before brewing. For milk drinks, our guide to texturing milk at home covers the rest.

Our blends and single origins are roasted to order and shipped fresh. If you're still struggling with your shots, get in touch and tell us which machine and grinder you're using. We're always happy to help you dial in.