Follow us on social

Essential Journal

  /  Food & Drink   /  From Bean to Barista and Beyond

From Bean to Barista and Beyond

As it turns out, there’s a whole lot of science behind that morning coffee. La Marzocco task some of the recent Out of the Box roasters with explaining the delicate processes behind some of the humble bean’s boldest flavours

It’s safe to say that La Marzocco, the leading voice in espresso machines since 1927, know a thing or two about a good cup of coffee. They know that, like their machines, a good cup of coffee is the final product of innumerous unseen and intricate processes. Speaking to a few of their roastery partners from across the country, La Marzocco get the lowdown on the subtle science behind everyone’s favorite pre-work/post-work pick-me-up. EJ

Nathan Retzer
Quarter Horse Coffee, Birmingham

Tereza Vertatova
Curve Coffee Roasters, Margate

Scott James
Coaltown Coffee Roasters, Ammanford

Nicole Ferris
Climpson & Sons, London

Rob Butterworth
Butterworth & Son Coffee Roasters, Suffolk

First off, tell us a little about your roastery.
Nathan Retzer, Quarter Horse Coffee, Birmingham: We’re a small roastery located in Birmingham City Centre. We’ve been in business for seven years, and we’ve been roasting for over four years. Our roastery and café space has been featured in magazines and newspaper articles as one of the top 20 cafes in the UK, and one of the best outside of London.  

Scott James, Coaltown Coffee Roasters, Ammanford: We’re based in Ammanford, South West Wales, at the head of the valleys and the base of the black mountains. We’ve been in production for five years and have grown to a team of 30. Our ambition is to bring a new industry to our town and other post-industrial towns across the UK with the new black gold: Coffee.

Nicole Ferris, Climpson & Sons, London: We’re an independent specialty coffee business with a roastery, two cafés and market stall, based in Hackney, East London. Previously a butchers, Climpson & Sons gained its first concrete home in Broadway Market in 2002, after Ian Burgess saw the opportunity to grow from a market coffee cart, to a cafe in the centre of a thriving and vibrant community. Once Ian decided he would give roasting a go in 2005 there was no going back, and we have been roasting for ourselves and other businesses for a long time.

Tereza Vertatova, Curve Coffee Roasters, Margate: We’re a pretty small team of just three people working in the roastery and another five working in our café, all based by the sea in Margate. We set up the roastery just three years ago and opened the café a year and a half ago. We focus on sourcing a small number of different single origin coffees with exciting and distinct flavour profiles. Our main goal is to get people to think and feel differently about coffee, move away from the perception of it as an everyday commodity, and really appreciate both its origins and the hard work and determination of the people behind producing it. Every coffee has a particular story and we want to celebrate it.

Rob Butterworth, Butterworth & Son Coffee Roasters and Tea Smiths, Suffolk: Based in Bury St Edmunds in Suffolk, the heart of East Anglia, we’ve been roasting since 2011. Our very own Howard Barwick placed third at the UK Barista Championships and we achieved the best espresso in issue 4 of Caffeine Magazine, all within our first 12 months of roasting. Our Head Roaster Tom Howes has added another dimension to our unique packaging by adding his much sought after illustrations to the labels. Check out his insta

Outside of the roast, what are the other elements that can impact a coffee’s flavour? Can you perhaps pick one element and offer detail around the effect it has?
Nathan: Process is something that can really change the cup. For two years, we have been getting in the same coffee from El Salvador that is processed in three different ways: Washed, Honey, and Natural. With the washed process, the coffee is more nutty, sweet, and clean. The Natural is very jammy and fruity, with a heavy body. The Honey process gives you a sweet, light fruit flavour while keeping the clean cup taste. It is amazing to try when you think everything else about the coffee has remained the same.    

Scott: Ensuring coffee is stored correctly is a huge contributing factor to the cup’s flavour and clarity. There is a lot of contention in regard to the best practise, but keeping your beans in an airtight container away from direct sunlight and away from moisture is your best bet. 

Nicole: Like cooking, following a recipe will give you amazing results. You wouldn’t guess the ingredient quantities baking a cake, would you? In coffee, it is no different. You need quality, fresh ingredients and a scale to measure them to get the best results. For a cafetiere, for example, we aim for 60g of coffee to 1L of water. For best results, freshly grind your coffee and weigh it out. You then want to add water – preferably filtered. Time is an important consideration too. You don’t want to overcook or undercook your cake, after all. The time also relies on the grind size: If you need to cook for less time; the texture of your coffee can become coarser. If you need to cook for a little longer, make the coffee finer.

Tereza: Oh, there are so many elements! Most of them really happen at the farm level. With roasting, we’re only uncovering and bringing out the best of what is already in the beans. Farm management, plant nutrition, and good harvest practices are where it all really starts. One of the elements that comes to mind now is agroforestry. For example, in Guatemala (and many other origins) most coffee is shade grown, meaning that the coffee plants are grown under a canopy of shade trees. These are often a mix of local trees like Gravilleas and Challums and fruit trees such as mangoes and bananas. These provide protection from winds and direct sunshine, and combined with high altitude, this allows cherries to mature slower and develop more sweetness, complex acidity and flavour which translates into the beans too. At lower altitudes, providing shade for coffee growing is often used to mimic cooler climates found at higher altitudes, and it is believed to have a positive impact on sweetness, acidity and body in the final cup. Agroforestry is also great for environmental reasons, it will allow us to diversify the plants grown in an area and create a polyculture, and it will often provide a habitat for local fauna.

Ripe cherry selection during harvest is also absolutely essential. Fully ripe red cherries will have the most sweetness and the best flavour in the cup. And good post-harvest processing and drying practices are also important in order to avoid any defects. The list goes on!

Rob: It’s pretty difficult to pick just one element beyond roasting, as espresso machine, grinder and water filtration all pay a massive part. If I were to pick one element that may get missed, it would be the freshness of roasted coffee. It’s a major factor in the flavour: too fresh and the flavours won’t have developed properly, and roasted coffee that has been exposed to the elements for too long will become stale and lose its flavours.

Do particular beans and how they are roasted lend themselves to particular serves? Are certain roasts from certain farms better suited to filter rather than espresso methods, for example?
Nathan: I think in general you need to roast coffee for espresso a little bit differently. The extraction process for espresso means you need to develop a bit more of the sweetness that is in the bean. You can also go a bit darker in the roast, as the roast flavour doesn’t come through in espresso in the same way it does in filter coffee.

Scott: For us, having a clear understanding of how our coffees are best prepared is important, so roasting for espresso or filter is a huge factor. Some coffees benefit from a slightly longer profile. This improves solubility without sacrificing the flavour notes in the cup and allows the coffee to sing through milk. More delicate coffees, on the other hand, need a little less heat.

Nicole: We roast to emphasise the coffee’s inherent sweetness and highlight the terroir. The more developed a roast is (i.e if too developed), the more it may taste overly bitter or burnt. If a roast is underdeveloped, it will give more earthy, vegetal flavours. Our aim is to develop the coffee to find the sweet spot to showcase the coffee for what it is. This requires a lot of knowledge about how you roast (and you can learn the basics at our brand new Home Roasting Course, as it happens), as different coffees react differently in the roaster. No coffee acts the same, so our roasters are highly skilled in the science and art of roasting. 

To highlight the bright acidity found in African coffees, for example, a lighter roast used for a filter coffee may generally be the best way to deliver these delicate, tea-like flavours. An espresso roast, on the other hand, may be more developed in order to promote more body and sweetness and to ‘cut through’ the milk if required.

Tereza: Yeah definitely! We think that most coffees can be roasted in a lot of different ways, each allowing to bring out certain characteristics. But certain beans will naturally be richer in body (which tends to be a characteristic favoured in espresso), whilst others might be fruit-driven and super high and complex in acidity (such as Kenyan coffees, which we would usually roast for filter). There are a lot of coffees that we roast for both brewing methods, and find it fun and interesting to explore the variety of flavours that can be brought out from one particular coffee. With every roast we do and taste, we try to learn more and understand a particular coffee better. We’re always aiming to bring out maximum sweetness and complexity without adding any ‘roasty’ or ‘ashy’ notes from pushing the roast a bit too far.

With our espresso roasts, we focus on full body and sweetness whilst taming the acidity, as it can be really highlighted in espresso extraction. With filter, we tend to let the bright, fruity and floral notes really shine whilst being supported by a good amount of sweetness. But there always has to be balance with acidity, bringing a nice brightness and liveliness to coffees without being overpowering or turning sour.

Rob: I’m sure many roasters could debate this forever! Kenyan beans, for example, have oodles of citrus acidity which some roasters love to showcase (often to the detriment of the coffee itself, depending on who you ask). Others may choose a roast profile that softens the acidity and allows the consumer to drink more at the sacrifice of the cup (again, depending on who you ask). I think every roaster has their own style, and consumers vote with their wallet to some extent. It’s a really interesting dynamic when you think about it.

For more from La Marzocco UK & Ireland head to