A double espresso is standard in most cafés. At home, however, there's often confusion: How much coffee goes in? How much liquid comes out? And why does the single often taste worse? We clarify the quantities, ratios, and the difference that matters in the cup. (You'll find basics on preparation in our espresso brewing guide.)
What a double espresso is
A double espresso (Doppio) uses double the amount of coffee compared to a single espresso and delivers double the amount into the cup. The standard values:
Double espresso: 16–20 g coffee in, 32–40 g espresso out (approximately 40–50 ml in the cup). Single espresso: 7–10 g coffee in, 14–20 g espresso out (approximately 20–25 ml in the cup).
At Kaffeemacher we usually work with 18 g coffee for a Doppio. That's the amount most double baskets are designed for. Then 36 g goes into the cup with a 1:2 brewing ratio, and 45 g with a 1:2.5 ratio, which we recommend for many coffees.
Grams, milliliters, volume — why they're not the same
A common confusion: 36 g of espresso is not 36 ml. Espresso contains crema, and crema has less density than water. In practice, 36 g of espresso is closer to 40–50 ml of volume in the cup. The exact amount depends on how much crema your coffee produces.
That's why we always weigh espresso in grams and not milliliters. A measuring cup is useless for espresso recipes. A scale that displays precisely to 0.1 g is inexpensive in our shop and makes your espresso preparation immediately more reproducible. It's the most sensible investment you can make in your setup.
Why the Doppio almost always tastes better
We generally recommend the double espresso. Not because more coffee is automatically better, but for a physical reason.
A double basket is designed for a specific amount of coffee — its geometry, depth, and hole distribution at the bottom. If you only fill 7–10 g into a single basket, a thin coffee layer forms that builds up significantly less resistance than intended. Small density variations in the puck that don't matter with a Doppio become channels with a single: water pushes coffee particles aside, the resulting gap channels water through faster, which enlarges the channel further. The result is often uneven extraction — overextracted in some places, underextracted in others. The espresso then tastes simultaneously sour and bitter — a typical channeling problem.
At 16–20 g of coffee in the double basket, the puck is as deep as the basket is designed for. Water distributes more evenly, the puck resists small irregularities better. Extraction becomes more homogeneous, flavor clearer. Many problems beginners have with single espresso disappear with the Doppio automatically — not because magic happens, but because the equipment is used as it was built.
If you only want to drink a small amount of espresso: Make a Doppio anyway and drink half. Or use the rest for a cappuccino. The result is usually better than a single from the single basket. And most of the time someone in the household or a neighbor will be happy.
Single espresso insider tip
A compromise is 14–15 grams in double baskets or large single baskets like we have in the shop. Our single basket can hold up to 14 grams of coffee. With a 1:2 brewing ratio, you'll end up with 28 grams of espresso. This way, the single espresso also becomes a delicious shot.
Brewing ratio: The number that really counts
The brewing ratio describes how much coffee goes in and how much espresso comes out. With a 1:2 ratio, 1 g of coffee yields 2 g of espresso.
18 g coffee → 36 g espresso = 1:2. That's the standard range for most coffees. Lighter roasted coffees often tolerate more water (1:2.5), darker roasted sometimes less (1:1.5 to 1:1.8).
Where 1:2 stands in global comparison is shown by a field study by André Eiermann (2024): He measured espresso shots in 85 cafés from 11 countries for a total of 106 shots with a refractometer. Specialty coffee cafés averaged 9.4% TDS (total dissolved solids in the cup). A well-pulled Doppio with 18 g and 36 g output lands exactly in this range. Commercial cafés came in at 6.4% TDS, super-automatic machines at 5.2%. So the 1:2 ratio is not an arbitrary value — it's the parameter that espresso bars work with when they care about extraction quality. Those familiar with traditional southern Italian espresso will find this ratio significantly lower, by the way: Neapolitan espresso is often pulled considerably more concentrated.
One more thing about whether Doppio and single espresso taste identical at the same ratio: usually similar, but not necessarily the same. A thicker puck extracts in horizontal layers — the uppermost coffee layers become saturated earlier and extract differently than the lowermost, which still work in the full extraction window. Those who switch between single and double baskets and wonder about a taste difference at the same recipe: that's the reason.
Our recipes always specify coffee amount, brewing ratio, and time window. With these three values, you can transfer any recipe to your machine.
Flow time: Single vs. double espresso
Does a double espresso have to run longer? Not necessarily. With double the coffee amount in the larger basket and double the water amount, resistance and flow rate typically scale proportionally. The extraction time often stays in the same window at the same brewing ratio — typically 25–30 seconds.
If your Doppio runs significantly faster or slower than your single at the same parameters, it's almost always the grind size that's the problem. When switching between single and double baskets, you need to adjust the grind size because the cake thickness changes, and with it the resistance.
Our recommendation: Settle on one basket size (preferably the double) and optimize your grind size for it. Constantly switching between single and double baskets makes adjustment unnecessarily complicated.
Caffeine: Double the amount?
Yes, roughly. A double espresso contains approximately twice as much caffeine as a single because twice as much coffee powder is extracted. At 18 g of coffee, you'll land around 120–140 mg of caffeine depending on variety and roast level — this value varies because caffeine content differs depending on the Arabica variety and origin. A single espresso with 9 g of coffee correspondingly contains around 60–70 mg.
For comparison: A cup of filter coffee (200 ml) contains 80–120 mg of caffeine depending on preparation. So the double espresso has slightly more caffeine than a normal filter coffee, even though it looks much smaller in the cup.
Our Sueño Espresso is decaffeinated using the chemical-free Mountain Water Decaf process in Mexico. For those who like to enjoy espresso in the evening, the Sueño is the perfect complement to your espresso hobby.
Ristretto, Lungo, and Espresso: The variations
Aside from the standard 1:2 ratio, there are two common variations often confused with the Doppio:
Ristretto (1:1 to 1:1.5): Same amount of coffee, but less water. 18 g coffee → 18–27 g espresso. Shorter, more concentrated, less bitter, but often more acidic. The ristretto is not a "stronger espresso," but a different balance of flavor compounds. Those who drink a very small, very intense espresso in a traditional southern Italian café are in this range — there, less coffee is often used, but with a short pull, which produces a similar concentration.
Lungo (1:3 to 1:4): Same amount of coffee, but more water. 18 g coffee → 54–72 g espresso. Thinner, more volume, often more bitter because extraction runs longer. Not the same as an Americano, where hot water is added to finished espresso.
The coffee amount stays the same for all variations. What changes is only the water amount — and with it the brewing time and taste. If an espresso tastes too sour, a little more water (toward 1:2.5) can help. If it tastes too bitter, a little less (toward 1:1.8).
Café Crème (Switzerland): Switzerland's most-consumed coffee beverage isn't a lungo — even though it comes out similarly large in the cup. The difference lies in the recipe: with Café Crème, you brew with 12–15 g coffee in a double basket and a 1:8 to 1:10 ratio, the grind is significantly coarser than espresso. From 15 g of coffee, around 120–150 g comes into the cup in 25–30 seconds. If you prepare a Café Crème as a lungo — same grinder setting, just more water — you get overextracted, bitter coffee. A good Café Crème needs its own grinder setting, ideally a second grinder. Everything about the history, brewing recipes, and the question of whether coffee cream is really necessary is explained in our detailed Café Crème article.
The key data at a glance
Double espresso: 16–20 g coffee, 32–40 g into the cup, 25–30 seconds. 1:2 brewing ratio as a starting point. Usually tastes better than the single because extraction runs more evenly. Contains approximately 120–140 mg caffeine.
Want to understand your brewing time better? Then read our article Espresso Extraction Time: When Does Brewing Time Really Start? — including the +3-second rule for vibration pumps.
And if your espresso doesn't taste good despite the right amount: Take a look at how to adjust your grind size correctly and what you can do if your espresso tastes too sour.
