How to Dial In Espresso at Home

Dialling in espresso is the process of adjusting variables until your shot tastes the way it should. It sounds outwith the reach of a home barista, but the principles are straightforward and the results of getting it right are dramatic.

This guide covers everything you need to know to move from guesswork to consistent, delicious espresso at home.

What Does “Dialling In” Actually Mean?

An espresso shot is produced by forcing water under pressure through a puck of finely ground, tightly packed coffee. The variables you control are:

Grind size: how finely the coffee is ground
Dose: how much ground coffee you use (in grams)
Yield: how much espresso comes out (in grams)
Time: how long the extraction takes (in seconds)
Temperature: the water temperature (in °C)

When these variables are in the right relationship, the shot extracts properly and tastes balanced: sweet, complex, with appropriate acidity and bitterness. When they’re wrong, you get sour or bitter coffee.

Dialling in is the process of finding that right relationship for your specific coffee, grinder, and machine.

What You Need

Before you start, you’ll need:

A burr grinder with adjustable settings. Blade grinders cannot produce consistent espresso.
Scales that read to 0.1g, small enough to sit under your portafilter or cup. Cheap kitchen scales are fine to start.
A timer. Your phone works perfectly.
Fresh coffee. Beans roasted within the last 2-6 weeks. Stale coffee is harder to dial in and tastes worse regardless of technique.

Optional but helpful: a shot glass or small jug to catch the espresso and weigh it, and a dedicated espresso distribution tool or WDT (Weiss Distribution Technique) tool for more even puck preparation.

Understanding Extraction: Sour vs Bitter

The most important thing to understand is the relationship between extraction and flavour:

Under-extracted espresso (too little extraction) tastes: sour, sharp, thin, hollow. Like lemon juice mixed with coffee.

Over-extracted espresso (too much extraction) tastes: bitter, harsh, dry, astringent. Like you dissolved old coffee grounds in hot water.

Well-extracted espresso tastes: sweet, balanced, complex. The pleasant bitterness is in the background. The acidity is clean, not sharp.

Your goal is to move from either extreme towards the middle.

The Standard Starting Recipe

For most espresso blends and single-origins roasted for espresso, start here:

Dose: 18g ground coffee in
Yield: 36g espresso out (a 1:2 ratio)
Time: 25-30 seconds
Temperature: 93°C (or your machine’s default if no control is available)

This is not magic. It’s a widely used starting point that produces good results with most espresso coffees. You’ll adjust from here.

How to Make Adjustments

The Golden Rule: Change One Thing at a Time

If you change the grind size and the dose simultaneously, you won’t know which change caused which result. Change one variable, taste the result, then decide whether to change the same variable again or try something else.

Adjusting for Sourness (Under-Extraction)

If your shot tastes sour, thin, or hollow, you need more extraction. Try these in order:

Grind finer: A finer grind slows the water down, increasing extraction. This is usually the first adjustment to make.
Increase dose slightly: An extra 0.5-1g can help if grind adjustment alone doesn’t fix it.
Check your tamp: Inconsistent tamping creates channels where water flows through quickly without extracting properly. Tamp level with consistent pressure (15-20kg is a common guideline).
Increase temperature: If your machine allows it, try 94°C.

Adjusting for Bitterness (Over-Extraction)

If your shot tastes bitter, harsh, or astringent, you’re extracting too much. Try:

Grind coarser: A coarser grind lets water flow through faster, reducing extraction.
Reduce dose slightly: Half a gram less can help.
Shorten the shot time: If you’re pulling 35+ second shots, try stopping earlier.
Reduce temperature: Try 92°C if your machine allows.

What If It’s Both Sour and Bitter?

This usually means channelling: water is finding paths of least resistance through the puck, over-extracting some coffee and under-extracting other parts simultaneously. Focus on puck preparation: distribute your grounds evenly before tamping, tamp level, and ensure your basket is clean and dry.

Tracking Your Shots

Keep notes. It sounds like overkill but when you’re on your seventh adjustment and you can’t remember what you changed, written notes save you from going in circles.

A simple format: date, coffee, dose, yield, time, grind setting, tasting notes. After a week of dialling in, you’ll have a record you can refer back to and patterns will become clear.

The Role of Coffee Freshness

Fresh coffee (2-6 weeks from roast date) behaves differently from old coffee. Freshly roasted beans off-gas CO2, which means:

Very fresh coffee (within a week of roast) can produce inconsistent shots and a lot of foam. Let it rest.
Coffee more than 6-8 weeks from roast becomes stale, harder to dial in, and tastes flat regardless of technique.

Most UK specialty roasters print roast dates. Use them. Buy fresher coffee and buy it more often.

Espresso with Milk: Does Dialling In Still Matter?

Yes, perhaps even more so. The espresso base of a flat white or latte needs to be well-extracted to stand up to milk. A poorly extracted espresso loses its identity under steamed milk and you end up with expensive warm milk. A well-extracted shot gives your milk drink structure, flavour, and character.

The parameters shift slightly for milk drinks: many baristas use a slightly longer yield (38-40g out from 18g in) to ensure the espresso isn’t too concentrated when diluted with milk.

Common Mistakes

Not weighing in and out: Guessing dose and yield makes consistent results impossible. Buy scales.

Changing too many variables at once: See above. One change, taste, assess, then adjust.

Using stale coffee: No amount of technique will save old beans. Check roast dates.

Inconsistent tamping: An unlevel tamp creates channelling. Take a moment to tamp level every time.

Not cleaning the machine: Coffee oils go rancid. Run a backflush (if your machine supports it) weekly and clean the portafilter and basket properly after each use.

When You’ve Found Your Recipe

Once you’re consistently pulling shots that taste the way they should, write down every parameter. Grind setting (on your specific grinder), dose, yield, time. When you get a new bag of coffee, especially from a different roaster or with a different roast level, you’ll need to dial in again. Coffee is different from bag to bag, and this is part of the process.

The good news is that each time you dial in, it gets faster. Within a few shots, you’ll have a feel for which direction to adjust and why. That intuition is what separates good home espresso from exceptional home espresso.

Summary: The Dialling In Process

Start with 18g in, 36g out, aiming for 25-30 seconds
If sour: grind finer
If bitter: grind coarser
Change one variable at a time
Keep notes
Use fresh coffee
Maintain a consistent puck preparation technique

It’s not complicated. It takes practice and patience, but the results are worth it. A well-dialled home espresso is as good as what you’ll find in most UK coffee shops, made in your kitchen, for pennies a shot.