How Many Bars of Pressure is Good for Espresso?

I’m an espresso enthusiast and want to brew the best drinks every time. That led me to write this guide on the ideal pressure for brewing espresso.

We will cover:

Let’s dive in.

What Is the Ideal Pressure for Espresso?

9 bars is the ideal amount of pressure for brewing espresso [1]. Many folks also consider 7–11 bars of pressure optimal as well. However, most espresso machines will utilize 9 bars of pressure. Even if they specify they can use more.

Let’s check out 

• <7 bars: under-extracted; super sour
• 7–9 bars: Mild flavor & a bit sour
• 9 bars: sweet spot; balanced flavor & excellent starting point
• 15 bars: stronger-tasting drink, but not too bitter
• >15 bars: over-extracted drink; excessively bitter

You’ll over-extract your drink if you use more than 15 bars of pressure. Doing so will result in a bitter-tasting drink. Fewer than 7 bars of pressure will result in under-extracted (sour) coffee.

Also, if you go under 7 bars of pressure on your machine, you won’t get crema, the golden foam on top of espresso. You need at least 7 bars of pressure for crema to form on top of your espresso shots, which is why many “espresso-style” devices don’t create proper espresso.

You may like the way over- and under-extracted drinks taste. I don’t recommend either, but I do recommend experimenting. Get a pressure gauge for your espresso machine and tinker with your steam application.

You can’t experiment with different bars with espresso machines in many scenarios. Most devices will have internal restricting valves that prevent them from brewing more than and under 9 bars of pressure. It’s a safeguard to prevent over- and under-extraction.

You can adjust your machine’s brew pressure, though. Doesn’t matter whether you’re using a home or commercial machine. You’ll need to find your machine’s rotary or vibrating pump and adjust the screw until it reaches the pressure you want.

You’ll need a pressure meter for this. Some coffee makers will have pressure gauges built in. But most will require you to buy a separate one.

What are we talking about when we say “bars”?

What is a BAR?

A BAR (barometric pressure) refers to the number of atmospheres of pressure the espresso machine exerts on coffee grounds. It’s a metric unit commonly found on scuba tanks and home and commercial espresso machines.

If you’re from a country using imperial units, consider BAR as pounds per square inch (PSI). 

9 bars of pressure, for example, would mean that the machine would force pressure at 9 times the pressure of the atmosphere. Earth’s atmospheric pressure is 1 BAR.

Let’s check out a comparison of different machines that produce espresso and how much pressure they use.

Different Types of Espresso Machines & Their Pressure Capabilities

Now we’ll talk about the following types of machines and the pressure used:

• Espresso machine: Traditional way of making espresso.
  • Manual: Requires manual input w/ every step of espresso making.
  • Semi-automatic: Automates temperature regulation & pressure application.
  • Automatic: Automates shot timing, temperature, & pressure.
  • Super-automatic: Automates everything.
• Capsule makers: Add a pod to a machine & let it brew.
  • Nespresso: All models produce espresso; some produce black coffee.
  • Keurig: Mostly produces black coffee.
• Stovetop coffee makers: Uses steam to brew an espresso-style drink.
• Coffee percolators: Uses boiling water to brew concentrated coffee.
• AeroPress: Uses air pressure to force hot water through coffee grounds.

All espresso machines use 9 to 20 bars of pressure. This goes for manual, semi-automatic, automatic, and super-automatic espresso makers. Some niche semi-automatic models will use 15 to 20 bars, often producing a more potent drink.

Semi-, super-, and regular automatic espresso machines will automatically apply pressure. Manual espresso machines use a spring piston or direct lever to create pressure.

All Nespresso machines use 19 bars of pressure. However, the higher pressure doesn’t result in a bitter-tasting drink. I couldn’t find why they use 19 bars of pressure instead of 9 other than their typical marketing spiel.

I’d imagine they need 19 bars of forge because they’re penetrating aluminum capsules.

The 19 bars of pressure go for Nespresso Original and Vertuo line machines. The former machine produces espresso. The latter makes black coffee and espresso drinks.

Other than the Keurig Rivo, all Keurig models use less than 1 bar of pressure [2]. Meanwhile, the Rivo uses up to 15 bars of pressure. The rare Keurig machine that’ll give you actual espresso.

Most moka pots use 1 bar of pressure to brew concentrated coffee. Models like the Bialetti Brikka will use up to 2 bars of pressure. Coffee percolators will also use 1–2 bars.

Despite the low pressure, moka pots and coffee percolators produce drinks comparable to espresso for a fraction of the price. They don’t include steam wands to create milk-based drinks, but they’ll make robust and flavorful coffee.

And due to the lack of pressure from Keurigs, moka pots, and coffee percolators, you won’t have crema. An essential component that makes espresso what it is.

An AeroPress will use 0.35–0.70 bars when using the plunger to force hot water through the coffee grounds inside the device. This device also produces an espresso-style drink that’s not espresso. Due to the lack of pressure and crema.

Pressure isn’t the only factor affecting your espresso drink’s taste.

Other Factors That Affect the Taste of Espresso

Other factors that’ll impact your home and commercial machine’s espresso’s taste include:

• Bean variety: The type of coffee bean used will have an impact on the flavor.
  • Arabica beans are the best for espresso, as they have a complex flavor profile with a good balance of acidity & sweetness.
  • Robusta beans tend to taste more bitter.
• Roast level: Lighter roasts will have more acidity & fruity flavors, while darker roasts will have more of a bitter & chocolate(y) taste.
• Grind size: If the grind is too fine, the espresso will come out too bitter. If too coarse, the espresso will come out weak.
• Extraction time: The ideal extraction time for espresso is around 25–32 seconds [3].
  • If the extraction time is too short, the espresso comes out weak & watery. If too long, the espresso will come out bitter & over extracted.
• Water quality: The ideal water for espresso is filtered or bottled water with a low mineral content.
• Brewing equipment: A high-quality espresso machine will produce the most consistent & flavorful espresso.

There’s also ensuring your machine’s clean. If your device has accumulated coffee bean oils on components, you’ll have funky-tasting coffee. Clean and descale your machine often.

And there’s bean storage. If you don’t store your beans in an airtight container, they could taste stale because of becoming oxygenized.

Now that you know everything affecting your espresso’s taste, let’s brew some drinks.

How to Make Espresso at Home

Follow these steps to make a great-tasting espresso at home.

1. Choosing the Right Espresso Machine

Consider the following factors when shopping for a home or commercial espresso machine:

I won’t explain all the criteria in this post. I did that in a separate guide. Use all what I mentioned to help guide you on finding the best espresso machine.

2. Grinding the Coffee Beans

Grind your beans to a fine grind that’s finer than table salt. If you don’t want a grinder, consider using easy-serve espresso (ESE). They’re pods filled with pre-ground espresso grounds.

Not all espresso machines will support ESE pods, though. Check the product description to see what it supports.

3. Measuring the Coffee & Water

Fill your machine’s water reservoir and measures out the following amounts of coffee grounds based on what you’re brewing:

• Single shot: 6–8 grams per 1–1.5 fluid ounce.
• Double shot: 15 grams per 2 oz.

A solo shot of espresso is 1–1.15 fluid ounces, hence, you’ll need to add 6–8 grams of finely-ground coffee. And doppio (double shots) requires double the amount.

If you’re using a manual espresso machine, you must measure and boil the water in a separate water-boiling device (e.g., kettle).

4. Brewing the Espresso

Those using manual and semi-automatic espresso machines must time their shots. Those using the former machine will use a piston or lever to apply pressure and squeeze espresso from your grounds. The rest of the machines require pressing a button.

From thereon, wait for the water boiler to heat and spray water over your coffee grounds. Then wait for your espresso cup to fill.

5. Enjoying Your Espresso & Cleaning Your Machine

Once finished brewing, enjoy your drink. If you want a drink like a cappuccino, grab a cup of milk and use a steam wand to create microfoam over it. Otherwise, add your espresso shot to one of a million drink combinations.

Different Bars of Pressure Compared

The following sections will compare different bars of pressure and what their resulting drinks would taste like.

1. 9 Bar vs. 15 Bar Espresso

9 bars of pressure is ideal for pulling espresso shots. Some espresso machines will use up to 15 bars. Will that make a difference in your espresso?

It doesn’t make a difference. Most espresso machines have an internal restricting valve. This valve prevents devices from brewing above 9 bars of pressure and over- and under-extraction.

2. 15 Bar vs. 20 Bar Espresso

20 bars would brew a much more bitter drink than 15 bars. However, most espresso machines have safeguards intact to prevent them from brewing more than 9 bars of pressure.

What Is Espresso?

Espresso is a strong, concentrated coffee made by forcing hot water through finely-ground coffee beans. It’s served in small shots and has a thick, creamy layer on top called crema. The crema is tiny air bubbles and coffee oils, giving espresso its unique flavor and aroma.

You could brew espresso shots in one of the following ways:

• Ristretto: Concentrated espresso shot.
• Doppio: 2 espresso shots.
• Lungo: A watered-down espresso shot.

Furthermore, you could make one of the following drinks with espresso:

Most of these drinks require a milk frother or steam wand to make macro- or microfoam. For instance, cappuccinos will need microfoam, which steam wands produce.

Most capsule machines, stovetop coffee makers, percolators, and AeroPress devices won’t have any means to froth or steam milk. Requiring you to buy separate milk frothers.

FAQs

Read on to find frequently asked questions about applying bars of pressure to espresso makers.

Conclusion

Home and commercial espresso machines brew the best-tasting coffee at 9 bars of pressure. However, you’re also in the safe zone if using 7–11 bars of pressure. 7 bars is the minimum for brewing crema on espresso.

Other types of machines (e.g., Nespresso) will use varying bars of pressure. Each will affect your coffee drink’s taste in different ways.

Need help finding a good espresso machine? Check out all our recommendations.