Dialing in espresso: dose, yield and time — three numbers, one variable at a time

With filter coffee, a small error in grind or temperature is forgiven: the water has time to compensate. In espresso, water crosses a puck of ground coffee, under pressure, in a few dozen seconds. Everything is compressed: one turn of the dial, one gram less, a cup weighed badly, and the taste shifts. That is why baristas talk about 'dialing in': adjusting an espresso, coffee by coffee, because freshly roasted beans, a bag that is ageing or a different humidity already move the balance. To find your way, you do not watch ten parameters, you follow three. The dose is the dry coffee that goes into the portafilter. The yield is the liquid espresso that comes out, weighed in grams. The time is the duration between the pump starting and stopping. These three numbers describe your recipe; the fourth actor, the grind, is the only lever you turn to correct it. Earlier Coffee-Note articles gave you the basics (why grind matters, how to read a cup that is too sour or too bitter): here we apply them to the most sensitive method of all.

The dose is the weight of ground coffee you put in the portafilter basket. It depends above all on the basket: an 18 g basket is designed for about 18 g, not 15, not 22. Weigh your dose to a tenth of a gram, every time. Do not trust dosing by eye: what looks like the same amount varies by several grams depending on grind and tamping, and those grams change the espresso completely. Our starting advice is simple: use the dose intended for your basket (often 18 g) and keep it fixed while you look for your setting. The dose is a frame, not a daily adjustment lever. If you change the dose, you are really changing recipe: everything else will need to be redone. If you do not yet have a precision scale, it is the most useful purchase before even changing grinder or machine, because without it you can neither reproduce a good espresso nor understand why another one failed.

Coffee beans weighed in a bowl on a digital scale, on a wooden table

The yield is the weight of espresso you get in the cup. It is measured in grams, with the scale under the cup, because volume is misleading: crema inflates the liquid, and a very fresh espresso has much more of it than an older one. The most common reference is the 1:2 ratio: 18 g of coffee gives 36 g of espresso. It is a reasonable starting point, not a law. From 1:1 to 1:1.5 we talk about ristretto: a dense, syrupy, more intense cup, which can turn very sour if pushed too far. Around 1:2 is the most common espresso, balanced: a survey quoted by the Specialty Coffee Association (2017, 275 baristas) gave an average of 1:2, with answers from 1:1.5 to 1:2.5. Beyond that we enter lungo territory, usually given as 1:2.5 to 1:4 depending on the guide: lighter, longer, with more risk of bitterness and astringency. According to several guides, light roasts, typical of specialty coffee, often ask for a longer yield (around 1:2.5 to 1:3), and dark roasts a shorter one (around 1:1.5 to 1:2). These ranges are rules of thumb that vary from one source to another, not a standard: your palate decides, by comparing two yields on the same coffee.

You have probably read that a good espresso lasts between 25 and 30 seconds. It is a useful starting reference, not a rule: the SCA's historical definition says 20 to 30 seconds, some roasters say 25 to 35, and a long pre-infusion on a light roast can legitimately stretch the time. Time is the consequence of your grind and your dose: the finer the grind, the harder it is for water to get through and the longer the time; the coarser, the shorter. Aiming for 28 seconds in itself makes no sense: you can hit it with a sour espresso, and with a bitter one. Use time as an indicator. An espresso that runs in under 20 seconds is probably too coarse; one that takes 40 seconds or more to drip, too fine. In between, the cup decides, not the timer. Start the timer when the pump starts, stop it when you cut it, note it, but taste before judging. If the time looks right but the cup is unbalanced, do not obsess over the number: go back to what you are tasting.

Espresso flowing from the portafilter during extraction

To dial in an espresso without getting lost, we apply the rule from the article on extraction: one variable at a time, and here it is the grind. Shot 1, the base: dose 18 g, target yield 36 g, starting grind medium-fine; note the time, taste. Shot 2, the first adjustment: if the cup is sour or hollow, grind finer; if it is bitter or dry, grind coarser. One small step, not three. Shot 3, confirm the direction: if the taste moved the right way, go one more step; if not, go back and check dose and yield. Shot 4, refine: when the cup is close, move only half a step, or adjust the yield slightly. Shot 5, lock it in and write it down: when it is good, record dose, yield, time, grind and what you taste. That is your recipe for this coffee, this week. If you change coffee, or if the bag ages, the recipe starts again from shot 1. And if the espresso flows unevenly, with multiple jets or spurts, think first about puck preparation (distribution, tamping) before moving the grind again: we will come back to it in a future article.

Here is how to turn what you taste into action. If the espresso is sour, sharp, hollow, with a dry finish like lime, it is probably under-extracted: the water has not dissolved enough of the coffee. First lever: grind finer, or lengthen the yield slightly; the time is often short, around 20 seconds or less. If it is bitter, ashy, astringent, drying the tongue, it is probably over-extracted: first lever, grind coarser, or shorten the yield a little; the time is often long, beyond 35 to 40 seconds. If it is flat, watery, without relief, the yield may be too long, or the dose too low for the basket: shorten the yield and check the dose. Finally, if it is both sour and bitter, it is a sign of uneven extraction: the water has carved channels through the puck, or the grind is inconsistent. Check distribution, tamping and the state of your grinder before touching the recipe. These times are indicative and depend on the machine and the coffee: the cup decides.

Your memory does not retain four numbers and a feeling from one Tuesday to the next. A notebook does. For each espresso, note the coffee and its roast date, the dose, the yield, the time, the grind (the grind field in the Coffee-Note notebook is made for this) and one sentence on what you taste: sour, bitter, round, sweet. Within three weeks, patterns appear: 'this coffee likes 1:2.2', 'my grinder drifts at the end of the bag'. You no longer adjust at random, you reason. To put the right words on the cup, our guide to learning to taste coffee gives you the vocabulary; to understand why grind matters so much, reread the article on the grinder; and if you want to understand what you taste in an espresso that is too sour or too bitter, the extraction article details the mechanism. The best setting is the one you have noted, compared, then improved by one small step. Sources consulted: Specialty Coffee Association ('Defining the Ever-Changing Espresso', 25 Magazine), Clive Coffee, Bean & Brew, Grain d'Expert, Coutume; benchmarks cross-checked, sometimes diverging, verified in October 2026.