There's a moment most home espresso people hit early on where they realise that having a good machine and decent beans isn't quite enough. The shots are coming out inconsistent. Sometimes sour, sometimes bitter, sometimes weirdly fast or painfully slow. Nobody told you about dialling in, and now here you are.
It sounds more complicated than it is. Here's what's actually going on, and how to get your grind right without losing your mind.
What "dialling in" actually means
Dialling in just means adjusting your grind size until your espresso is extracting at the right rate and tasting the way it should. Grind size controls how fast water flows through your coffee puck. Finer grinds slow the water down and extract more. Coarser grinds let water through faster and extract less.
Get it right and you get a balanced, sweet, complex shot. Get it wrong and your coffee tells you, pretty clearly, through taste.
The time benchmark: 25-35 seconds
A standard double shot, using around 18-20 grams of ground coffee, should take roughly 25-35 seconds to pull around 36-40 grams of liquid. That's the ballpark most home baristas aim for. If your shot is flying through in 15 seconds, you're grinding too coarse. If it's still dripping away at the 45-second mark, you're grinding too fine.
Time is your first feedback loop. But taste is the more important one.
Diagnose by flavour
Your coffee will tell you exactly what's wrong, if you know how to listen.
Sour, sharp, or thin-tasting espresso means under-extraction. The water moved through too fast and didn't pull enough out of the grounds. The fix: grind finer. This slows the water down, extends the extraction, and brings out more sweetness and body.
Bitter, harsh, or ashy-tasting espresso means over-extraction. The water moved through too slowly and pulled out too much, including compounds that don't taste good. The fix: grind coarser. This speeds up the flow and stops extraction before it tips into bitterness.
A useful way to think about it: sour means not enough, bitter means too much. Finer for sour, coarser for bitter. Write that on a Post-it note and stick it to your machine if it helps.
Change one thing at a time
The most common mistake when dialling in is changing too many variables at once. Grind size, dose, and tamp pressure all affect extraction. If you adjust all three together, you won't know which change made the difference.
Start with grind size. Keep your dose (the amount of coffee you're using) consistent, tamp with consistent pressure, and only adjust the grind. Pull a shot. Taste it. Adjust the grind by one notch in the appropriate direction. Pull another shot. Taste again. Repeat until it tastes right.
It might take five or six shots to land where you want to be. That's completely normal. Once you're there, write down the grind setting so you're not starting from scratch next time.
Why fresh beans make this much easier
Here's something that doesn't get said enough: stale beans are genuinely harder to dial in, because they behave inconsistently. Old coffee has lost most of its CO2, which means it doesn't create the same resistance in the puck. A grind setting that works perfectly with fresh beans might produce a completely different result with beans that are three months old. You end up chasing a moving target.
Fresh beans, ideally used within four to six weeks of roast, behave predictably. When you dial in a setting, it stays dialled in. That consistency is actually what makes the whole process manageable for home baristas.
Our Colombia Galeras Volcano is worth a try if you're after something easy to work with at home. It's got a clean, balanced profile that makes it very readable during the dialling-in process, you can taste the changes clearly as you adjust.
A quick reference
- Shot time under 25 seconds: grind finer
- Shot time over 35 seconds: grind coarser
- Tastes sour or sharp: grind finer
- Tastes bitter or harsh: grind coarser
- Tastes balanced and sweet: don't touch a thing
Give yourself a week of consistent shot pulling and you'll have a much better feel for your setup. It becomes intuitive faster than you'd think.
Have questions about dialling in, or stuck on a specific problem? Leave a comment below. And if you want beans that are fresh, roasted for home espresso, and built to work in milk drinks, pop to our shop.
