A guide to roasting for coffee capsules

Kahwei Yoong
December 15, 2021
roasting for coffee capsules

Coffee capsules have taken the sector by storm in recent years.

Quick, affordable, and widely accessible, they offer a convenient option for those looking to make coffee at home and in the office.

Rapid market growth, helped along in no small part by Covid-19, has also led to a surge in quality. Specialty roasters from Roastworks to Colonna now offer their own range of capsules as they look to capture a share of the $4 billion global market.

However, capsule machines have a unique extraction method that demands a certain style of roasting. As such, it’s important for roasters wanting to offer their own range to consider not only the coffee they choose, but the way in which they roast it.

To understand more about roasting for coffee capsules, I spoke with the founder of Difference Coffee, Amir Gehl.

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The popularity of coffee capsules has risen significantly in recent years

The growing popularity of coffee capsules

Over the last few years, coffee capsules have become a staple across many homes and offices worldwide.

The National Coffee Association has been tracking single-cup consumption behaviour since 2006. Among other things, they found that ownership of a single-cup machine in American households jumped from a mere 10% in 2012 to more than 40% in 2019.

Amir is the founder of Difference Coffee, a company that serves specialty coffee in the form of Nespresso-compatible capsules. He tells me that the popularity of coffee capsules is all thanks to its convenience.

“It is the fastest way to brew a consistent cup of coffee with perfect extraction, assuming it was manufactured correctly,” he says.

The simplified coffee-brewing process combined with consistent quality in quality and taste, as well as diverse choices, it is not surprising to find that coffee capsules sales soared during the pandemic.

In the midst of extended lockdowns and widespread disruption to out-of-home coffee consumption, capsules offered consumers an opportunity to recreate favourite coffee shop drinks from the comfort of their homes.

In particular, Nespresso and Keurig, two of the leading single-serve coffee brands, reported exceptionally strong performance during this period.

Nespresso announced a $170 million investment in its production centre in Switzerland, while Keurig reportedly acquired 3 million new users.

This growth has not gone unnoticed among specialty coffee roasters. Although traditionally on the periphery of the specialty market, many businesses have started to introduce their own take on the capsule model.

In addition to adding another revenue stream, Amir says they allow roasters to appeal to different groups of consumers, especially those who prioritise convenience.

As more and more specialty roasters offer their own coffee capsules, freshness has become a key concern

How to maintain the freshness and quality of capsules

Freshness is a cornerstone of the specialty sector. Defined as the original, unimpaired characteristics of coffee, it also tends to be used as a broad measure of quality.

As soon as coffee is roasted, it immediately begins to lose its freshness. This process only accelerates when the coffee is ground.

Because capsules contain ground coffee that often spends a considerable time on the shelf, many claim they don’t offer the same freshness as whole bean.

However, Amir explains that the capsule materials can help preserve the freshness and quality of their capsule coffee.

“There are many capsule bases and lids that can be used to put coffee in,” he says. “Some are high barrier, some are low barrier, and some have no barrier.

“You should certainly be looking for a capsule base and lid that offer a high barrier solution. That’s the only way you will preserve freshness.”

High barrier materials, such as aluminium, reduce the risk of exposure to oxygen, heat, moisture, and light. These four externalities can all have a negative effect on the freshness of coffee, causing its flavours and aromas to degrade over time.

In particular it limits oxidation, a process by which oxygen replaces the CO2 as it leaves the coffee. Oxidation tends to result in unpleasant, rancid-tasting coffee, which can dissuade customers from making repeat purchases.

In addition to high barrier materials, Amir says that it’s important to prepare the coffee capsules in a controlled environment, such as by nitrogen flushing.

Nitrogen flushing involves using nitrogen to remove any residual oxygen inside the capsules before sealing. Because it’s an inert, odourless gas, it doesn’t affect the coffee’s characteristics, but can extend its shelf life by several months.

Roast profile is an important factor to consider when offering coffee capsules

Additional factors to consider

Preserving the freshness of coffee capsules is clearly a priority for those who offer them. However, there are several other factors that are also worth considering, including roast profile.

Amir advises against using an existing espresso or filter roast for capsules. Instead, it’s better to create a specific roast profile.

Similarly, adjusting the grind size for capsules is also crucial since it will affect the extraction of coffee.

He tells me that issues with flow rate and extraction can be common when creating capsules.

“The number one tip I could possibly share is that you really want to make sure that you’re profiling for the coffee to be quite soluble.

“This doesn’t necessarily mean you have to make it really dark. You can still preserve the taste of coffee with a much lighter roast but you just need to experiment with your roast curve, end temp and everything else to make sure that it gives an acceptable level of solubility.”

Amir recounts how he once had to discard some 40 kilos of Esmeralda Geisha coffee when he first started developing the product.

“There is no formula to what it needs to be. It is trial and error, in the same way that it is for any application that we do. When you profile coffee for filter or espresso, you should also profile coffee for capsules.”

Indeed, a study on single-serve coffee capsules concluded that while there are some general rules for the development of capsules “fine-tuning of parameters for successful capsule coffee extraction remains specific to production line and type of coffee.”

Additionally, roasters should be mindful of the type of coffee system that they are producing for. Coffee extraction varies between different capsule machines, so adjusting parameters like dosage or grind size will be required.

All coffee packaging, from capsules to bags, should have a minimal environmental impact

While the need for convenience will continue to drive the future of capsules, Amir says that sustainability of packaging will also play a crucial role.

With a growing compostable packaging market and increasing environmental awareness, we can be optimistic for a future where the consumption of coffee, including capsules, will become more and more sustainable.

At MTPak Coffee, we are dedicated towards helping specialty coffee roasters transition towards sustainable packaging.

We offer a range of high quality packaging solutions made from recyclable, compostable and biodegradable materials, which lowers your carbon footprint and at the same time, keeps your coffee fresh for longer.

For information on our sustainable coffee bags, contact our team.

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