It has taken us 18 months to develop an espresso capsule that lives up to our promise of Iconic Flavour. At first glance coffee capsules are simple - you just push a button right? Not so fast! The basic principles of brewing coffee still apply. 

This article explores the idea of strength and how to get the best experience from your capsule. If you just want to learn how to brew your favourite cafe coffee, check out our coffee capsule brew guide - but for those that want to geek out, read on!

Strength vs flavour

Before we get into it, we need to address the elephant in the room - capsules are small. At 5.3g of coffee, they contain around one-quarter of the coffee used to make a double shot flattie in your favourite cafe and they are brewed on a machine that costs a fraction of the price of a commercial-grade espresso machine. They have to work hard.

How extraction works

Strength seems to be an important factor in the world of pod drinkers -  our eyebrows were raised by a 12/10 strength rating we saw recently. A lot of capsule coffee tries to overcome the challenges by roasting the coffee very dark, creating an illusion of strength by making the coffee taste more powerful - but not in a good way! This explains why so many capsules taste (and smell) burnt and rubbery. 

Our goal was to produce a capsule that tasted like Allpress Espresso Blend - sweet, balanced and complex. Our focus was great flavour, not strength. 

So less coffee = less strength? Kind of.

In any coffee brewing process, we are putting ground coffee beans in contact with hot water. The coffee is full of soluble flavour producing compounds that are extracted at different stages of the brew. The amount of extracted solids suspended in the liquid (Total Dissolved Solids or TDS) is the true measure of strength. 

Roasting the coffee darker does not directly increase strength - it can increase body and makes the coffee flavour more bitter creating the illusion of strength but it sacrifices great flavour in the process.

You can increase the TDS (strength) of your coffee by brewing for longer but, again, at the sacrifice of great flavour.

What happens during your brew…

First 15ml - In the early stages of brewing we are extracting the acids. These are important - they give us all the syrupy, fruity, jamminess but if we under-extract we will be left with a sour, lip-puckering brew. Not good.

15 - 25ml - As the extraction continues we start to dissolve the sugars and bitter compounds - somewhere in here we hit the sweet spot - the perfect balance of sweet, sour and bitter which is where we find optimum flavour. Yum.

25ml plus - If we continue to brew further we start to extract undesirable flavour compounds which cause overwhelming bitterness and a burnt rubbery taste. Also gross. The “lungo shot” is commonplace in capsule coffee and we strongly recommend you don’t brew like that.  

How to find the sweet spot

This sweet spot is directly linked to the amount of ground coffee in the capsule - we cannot change this. We crammed in the maximum amount of coffee (5.3g) and will taste great at a certain brew volume. Luckily for you, we have done most of the hard work for you. All you have to do is program your espresso shot to the right volume. 

Your Allpress capsule will taste best brewed as a 25ml shot. This extraction will give you the perfect balance of caramel sweetness, crisp apple acidity and complex bitters. Most Nespresso compatible machines brew at the same pressure (19 bar) so a 25ml shot should take somewhere between 15 - 25 seconds.

The rule that contradicts everything we just said…

"But I don’t want to use two capsules though!" Understandable.

If you want to make a flat white but only want to use a single capsule you have two options. Make a smaller flat white (AKA a Piccolo) or use over-extraction to your advantage.

By brewing your espresso shot to 40ml you will increase the bitterness of your shot which will cut through the milk better while the sweetness of the milk brings the drink back into balance. The perfect single-shot flat white. Check out our complete guide to brewing your favourite cafe coffee.

It’s very easy to program your capsule machine to brew a 25ml or 40ml shot - just follow our guide for how to reprogram your coffee capsule machine.