Espresso brew ratio: how much ground coffee for how much espresso

Brew ratio is the relationship between the mass of ground coffee (the dose, going in) and the mass
of beverage you end up with (the yield, coming out).

ratio = liquid mass in the cup ÷ ground coffee mass

18 g of grounds producing 36 g of espresso is a 1:2 ratio. The same 18 g producing 27 g is 1:1.5.
That is arithmetic and nothing more, which is exactly what makes it a dependable reference: it does
not care what brand your machine is, how big your basket is, or which country you drink in.

One vocabulary note, because it turns up everywhere: dose always means the input (dry grounds),
yield always means the output (liquid). When a roaster's recipe card reads "18 / 36 / 28 s", those
are dose, yield and time in that order.

This is the part people push back on, and it is the only item here worth changing a habit over: a
cup is not a unit of measurement.

Three reasons, in order of how much they cost you.

Crema is foam. What you see in the cup is liquid plus a layer of emulsified gas. That foam takes
up volume without weighing much, it collapses within a minute or two, and how much of it appears
depends mostly on how recently the beans were roasted. Two shots that are identical by mass can look
like different fill levels thirty seconds apart. Volume lies; a scale does not.

Espresso is not water. One millilitre of water weighs one gram, which makes the conversion
tempting. But espresso carries dissolved solids, so it is denser than water — the millilitre-to-gram
conversion is not neutral, and nobody does it correctly by eye. The same applies to fluid ounces,
with an extra trap: a US fluid ounce is a volume, not the 28.3 g weight ounce, and they are not
interchangeable here.

Cups are not standardised. The "1 oz" line moulded into a shot glass, the assumed capacity of a
demitasse, the mark on a measuring jug — every one of those assumes a geometry that is not yours. A
scale reading to 0.1 g removes the problem entirely.

That is also why the serious standards in this trade rest on measured quantities rather than a fill
line. The "Espresso Italiano Certificato" specification from the Istituto Nazionale Espresso
Italiano describes an Italian espresso with numeric tolerances: 7 g ± 0.5 g of ground coffee, about
25 ml ± 2.5 ml in the cup, a percolation pressure of 9 bar ± 1 bar, water at 88 °C ± 2 °C and a
percolation time of 25 s ± 2.5 s. Note the pressure figure in particular: 9 bar, not the 15 or 19 bar
printed on most pump cartons. That larger number is a pump peak, not the pressure at the puck.

TIMEMORE Black Mirror Basic 2 - Balance à café avec minuteur

These are the reference points specialty roasters use to describe a recipe. They are usage
conventions, not published standards — no body certifies "the 1:2". That distinction matters,
because half the pages covering this subject present these numbers as an official rule.

Two useful readings of that table.

A ristretto is not "an espresso that runs for less time". It is an espresso stopped earlier by
mass. If you stop earlier and change nothing else, you pull less material out of the coffee: the
cup is more concentrated but less extracted. That is a taste choice, not a superior version.

A lungo is not an americano. A lungo passes more water through the same puck; an americano is an
espresso with hot water added afterwards. Both end up with a comparable volume in the cup and taste
nothing alike, because the second one extracts nothing further from the coffee.

Here is the blind spot in most explanations, and the reason people change three settings at once and
never learn which one moved.

Ratio decides the concentration of the cup: how much water for how much coffee. Shot time
is an indicator of grind fineness and tamping — that is, of how much resistance the puck offers the
water. You do not set the time directly. You set the grind, and the time is what you observe back.

Put plainly:

• Want a more concentrated cup? Change the ratio — stop the shot earlier.

• Shot running too fast or too slow? Change the grind, not the ratio.

The test that makes the difference obvious: keep the grind exactly where it is and pull two shots,
one stopped at 36 g and one at 54 g. The second ran longer, necessarily — but you never touched the
grinder. Time followed the ratio; it did not cause it. Now go the other way: tighten the grind one
step and stop both shots at 36 g. Same ratio, different time, different cup.

A third quantity turns up in serious discussions: extraction yield, the percentage of the dry
coffee's mass that ends up dissolved in the cup. The Coffee Brewing Control Chart — descended from
E. E. Lockhart's work in the 1950s and still published by the Specialty Coffee Association —
places the target zone between 18 % and 22 % extraction. That chart was built for filter coffee, a
nuance too often dropped, and it remains the most-cited numeric reference in the trade. Measuring it
at home needs a refractometer, which is outside the scope of this guide — but it explains why ratio
alone does not fully describe a cup.

The list is short, and only one item is genuinely mandatory.

A scale that reads to 0.1 g

This is the tool the whole subject rests on. A normal kitchen scale reads to the whole gram: on an
18 g dose, one gram of imprecision is already over 5 % off, and on a 36 g yield it leaves you
guessing. Look for 0.1 g resolution, enough range to sit a cup and a portafilter on it, and ideally a
built-in timer so you can follow mass and time without looking away from the machine.

On a smaller budget, a pocket precision scale already handles the dose. Check its capacity before buying, though: a model capped at 500 g weighs grounds, not a cup sitting on the drip tray.

Balance de précision de poche 500 g / 0,01 g, écran LCD rétroéclairé

Form factor matters too: the scale has to fit on the drip tray, under the cup, without the
portafilter fouling it. Espresso-specific models are flat and narrow for exactly that reason.

A grinder you can adjust finely

The ratio is weighed, but it only holds if the grind is stable. A burr grinder produces a consistent
and — more importantly — repeatable particle size from one shot to the next; a blade grinder
chops randomly and makes any setting impossible to reproduce. It is the first upgrade that changes
anything in an espresso setup, ahead of the machine itself.

Baratza Encore ESP Moulin à Café à Meules Coniques

Keep the rule in mind: without a consistent grind, your scale is measuring a random result very
precisely.

Something to tamp with

Uneven tamping creates channels through the puck: water runs where resistance is lowest, part of the
bed stays under-extracted, and your ratio becomes a number that no longer describes anything. A
tamper of the right diameter — 51 mm or 58 mm depending on your machine, check yours — and a
consistent motion are enough.

De'Longhi DLSC058, tasseur à café 51 mm en acier inoxydable, manche en bois

A simple routine, worth running once per new bag of beans.

Shot 1 — set the reference. Weigh the dose (say 18 g), start the shot, stop at 36 g of liquid in
the cup, note the time you got. Taste it. This shot is your zero point whatever it tastes like.

Shot 2 — correct the grind, not the ratio. If shot 1 gushed and tastes sour and hollow, tighten
the grind one step. If it crawled and tastes bitter and harsh, open it one step. Repeat exactly the
same dose and stop at the same output weight: 18 g in, 36 g out. You are now comparing two cups that
differ only by grind.

Shot 3 — adjust the ratio for taste. With the grind holding, finally move the output. Thin or
bitter at the end of the cup? Stop around 30 g instead of 36 g. Too thick, too dominant? Push to
40 g. You are moving along the concentration axis, knowing exactly what you changed.

Write the three numbers down every time — dose, yield, time. Three figures in a notebook beat any
number of half-remembered settings.

A fair question, because a super-automatic gives you no portafilter to weigh. You do not control the
dose directly: the machine grinds an amount it decides, usually adjustable on a "mild / strong" scale
with no grams displayed anywhere.

You still have two real handles.

The output is always measurable. Put the cup on your scale under the spout and tare before you
start. The cup-volume setting that nearly every model has then becomes a mass setting: you learn once
and for all what weight your factory "espresso" actually delivers, and you correct it toward the
target you prefer.

The dose can be inferred. Most manufacturers state a grounds-per-cup range in the manual. Treat
the manual figure as a manufacturer estimate rather than a measurement, and compute your approximate
ratio from it. It will be imperfect, but it will tell you whether you have been drinking a 1:2 or a
1:4 without knowing. Plenty of super-automatics ship on a setting considerably longer than 1:2.

De'Longhi Magnifica S ECAM11.112.B - Perfetto Machine à Café Automatique avec Mousseur à Lait Manuel

If you want full control of both weights instead, a portafilter machine is what gives it to you — at
the cost of a manual routine on every cup.

De'Longhi Stilosa EC260.W, machine expresso manuelle à porte-filtre 51 mm

To compare the two families in detail, our
bean-to-cup machine comparison works through the buying
criteria one by one.

• Taring with the portafilter still resting on the scale. Tare with the empty cup on the
  platform, never before you place anything on it.

• Counting crema as liquid you can see. It is included in the measured mass, which is correct —
  what is wrong is judging the fill level by eye while it is still there.

• Changing two variables at once. Grind and dose and yield moved together: the result cannot
  be interpreted.

• Borrowing another coffee's ratio. Every bean, every roast profile and every degree of freshness
  shifts the balance point. A ratio is a recipe, not a constant.

• Confusing the displayed time with extraction time. On many machines the counter starts with the
  pump, pre-infusion included. Pick a convention and keep it.

• Reading the carton's 15 or 19 bar as brew pressure. That is a pump peak. The pressure at the
  puck targeted by the Italian certification cited above is 9 bar ± 1 bar.

Ratio is the first setting worth holding steady because it is the only one entirely under your
control and entirely measurable. Grind needs a decent grinder, temperature depends on the machine,
real pressure is rarely displayed — but two weights are something anyone can record.

Start there: weigh the dose, weigh the yield, note the time. Three numbers and a notebook, and most
of the mysteries of home espresso turn into variables you can move one at a time.