Understanding the Fundamentals
Dialing in espresso refers to the process of making espresso taste as delicious as possible by extracting the right amount of soluble flavor from coffee using the right amount of water . Espresso dialing simply means adjusting your variables—primarily grind size, dose, and yield—until your shot tastes the way it should. Think of it as calibration .
The three main parameters are dose, yield, and brew time, all of which have a massive impact on flavor. When dialing in, you should only adjust one parameter at a time, otherwise you can easily lose track of which has affected the espresso’s flavor . A good espresso extracts the right balance of these compounds. Too little extraction (under-extraction) leaves you with mainly acids and thin body. Too much extraction (over-extraction) pulls out the harsh bitter compounds. Perfect extraction gets the sweet spot in the middle where sourness and bitterness balance .
The beans change, the humidity changes, the grinder burrs wear down over time. The dial is never permanently set. Every new bag of coffee means you start the dialing in process again. Even the same beans from the same roaster will taste different a week off-roast versus three weeks off-roast .
Essential Parameters and Starting Points
Once your dose is locked in, adjust your grind size so that your shot parameters fall within the ballpark of a 1:2 ratio shot taking 25-35s . Set your dose to 18g of ground coffee. Target a yield of 36g of liquid espresso. That’s a 1:2 ratio—your desired espresso yield is double your coffee dose. Aim for a shot time of around 27 seconds for better espresso .
The dose is the amount of dry grounds that you place into your portafilter, typically measured in grams. Many baristas consider this the first step of how to dial in espresso. The dose should not be used to directly change the brew time or flavor of the espresso . Most double baskets take between 17g and 19g .
Brew ratio is the relationship between your dry coffee dose and the liquid espresso yield, measured by weight. A 1:2 ratio means 18g in, 36g out. It’s a cornerstone of consistent espresso dialing in . Different ratios produce distinct flavor profiles: Ristrettos (1:1–1:1.5) have more body, and taste much stronger, while lungos (1:3–1:4) are more balanced and clear, but sacrifice texture .
The Grind Size Adjustment Process
When you’re dialing in an espresso, grind size is always the first thing you adjust . A finer grind size will increase shot time, while a coarser grind size will decrease shot time . A finer grind will increase your extraction since smaller particles are more easily extracted, while also making your brew time go up since the water will have to work more to get through. This means that, for the same ratio and dose, a finer grind will make overall extraction go up in two ways .
If the shot runs faster than 20 seconds, your espresso grind size is too coarse—grind finer. If it runs longer than 35 seconds, go coarser. Make small adjustments. On most grinders, one or two notches is enough . Your grinder’s micro-adjustments are your best friend for espresso dialing in. Move in tiny increments—sometimes just one click—to fine-tune your flow rate. Patience and small steps lead to perfect shots .
A very important factor is your knowledge of your grinder. If your grinder retains a lot of grounds and you don’t realize it, you can end up chasing a shot around and around because leftover grounds from your previous grind setting are still in there. For some grinders, the retention can be as low as 0.1g or as high as 1g .
Puck Preparation and Distribution
WDT, or Weiss Distribution Technique, is a method of puck preparation that aims to evenly distribute coffee grounds in your portafilter, providing a more uniform and tasty extraction. The thin wires of the tool are used to rake the grounds before tamping, which breaks up clumps that can be left behind from your grinder . Left untouched, these clumps can cause uneven pockets or gaps in the tamped coffee bed, which typically leads to channeling and spurting during extraction. Not only does channeling and spurting cause a huge mess, but even worse, these are indications that your coffee is being extracted unevenly .
Channeling occurs when water flows through narrow paths in the coffee puck instead of evenly through the entire bed. The primary cause is poor distribution of coffee grounds before tamping . Poor puck prep leads to channeling. Water easily finds paths of least resistance through the coffee bed, resulting in under-extraction in some areas and over-extraction in others. This creates shots that taste both sour and bitter, lack sweetness, and cause spraying if you are using a bottomless portafilter .
Holding the WDT tool like a pencil, use a circular motion to stir through the grounds. Start at the bottom and lift the tool higher as you go. If you’re using dosing funnel, make sure to leave the funnel attached, which will help stop grounds from jumping ship! Gently distribute the grounds all the way up to the top layer. Give the portafilter a tap to help settle everything into place, then tamp as usual .
Taste-Based Troubleshooting
Sour espresso = under-extracted: Go finer, hotter, and longer. Bitter espresso = over-extracted: Go coarser, cooler, and shorter . If it tastes sour or sharp, it’s under-extracted. Either grind finer or extend your espresso yield slightly—say from 36g to 40g. This gives the water more time to extract soluble flavors . If it tastes bitter or ashy, it’s over-extracted. Go a little coarser, or reduce your yield .
The sweet spot lies between 90°C and 96°C (194°F and 205°F). Within that narrow window, coffee compounds dissolve at just the right rate. If the water is too hot, your espresso will taste burnt and bitter. Too cold, and you’ll get a sour, under-extracted cup. The goal is to find the precise temperature at which acidity, sweetness, and bitterness harmonize .
If your shots taste both sour and bitter, seemingly impossible, you’re probably experiencing channeling. This is when water finds easy paths through the coffee puck instead of flowing evenly . If your shot is tasting both bitter and sour at the same time, you’re probably extracting unevenly due to channeling—work on your puck prep!
Common Problems and Solutions
Fast shots gush out in under 20 seconds, yielding watery, sour espresso with thin crema. Causes include coarse grind, low dose, or uneven puck . Choking means the machine struggles, dripping for over 40 seconds, often bitter or astringent. Too fine grind, high dose, or clumping are usual suspects .
Usually 2 to 4 shots when using fresh beans and consistent technique. Adjust grind size first. Dose changes are secondary . Follow these steps in order and change only one thing at a time. If you adjust your grind size and your dose simultaneously, you won’t know which change fixed the problem .
Anything over 4–5 weeks old will start to flatten and taste woody. Run a backflush or wipe your portafilter regularly. Burnt oils are bitterness magnets . Fresh coffee is the foundation of great espresso , and old beans will consistently produce lackluster outcomes. Freshly roasted coffee is full of flavor and oils, and it makes your efforts at dialing in your espresso truly rewarding and tasty .