One of the many benefits of food's new-found popularity is the accompanying interest in specialty coffee – something that the founders of Union Hand-Roasted Coffee have championed from the start. Steven Macatonia and Jeremy Torz are now considered to be the grandfathers of our modern café culture, influencing everything from the way we brew to the way we consume. There's another important aspect to their company, too: Macatonia and Torz have seen first-hand how farmers are affected when the price of coffee falls, and as a result, Union Hand-Roasted Coffee invests long-term in farming communities and pay the farmers a fair, sustainable price. Their tireless work has been now been brought together for a new book, Real Fresh Coffee. Jeremy Torg tells us what to expect, why climate change could change our morning brew, and why as much emphasis should be placed on speciality coffee as on fine wine.

When did you realise you were so passionate about coffee?

We discovered our love for coffee in San Francisco in the 90s, where we first encountered fresh speciality coffee in the café culture revolution that was then taking place there. The taste was so striking and evocative, and the smell of freshly roasted coffee lingering in the air woke an ambition to learn to roast our own coffee.

What are all the elements of a great cup of coffee?

There's no one-size fits all method. There are lots of stages in the process, from weighing, to grinding, to extracting, and each stage of brewing changes the final cup in different ways. For simple ways to improve your coffee at home, whatever brewing method you use, consider weighing your coffee to ensure the ratio of coffee to water is balanced, and use filtered water to remove any impurities which could affect the brew. Make sure your water is just below boiling (about 94°C) to avoid burning the coffee and spoiling some of the flavours.

Where do you drink coffee when you're in London?

Anywhere that serves Union Hand-Roasted Coffee! Seriously though, Taylor St Baristas and Gail's are great outlets that care about what they do. The Baristas at Taylor St craft well- made brews, both espresso based and some great filters, whilst Gail's consistently proves that a café can offer amazing food as well as world-class coffees. We like to seek out independent cafes that offer good quality, balanced and well-roasted coffees.

How do different growing conditions affect the beans?

That's an incredibly broad question, but in simple terms coffee quality is directly affected by climate, access to water and the micronutrients available to the trees. Aside from good growing practices – fertilising, pruning and soil management, the topic on many people's minds at the moment is climate change and how coffee will respond to this. Arabica Coffee is grown in the semi-tropical belt, but has an upper range of 24°C, which if regularly exceeded can significantly weaken the trees and make them susceptible to disease and death. As global temperatures rise, we will see some lower lying areas become less suitable for coffee farming, leading to an overall reduction in the acreage of suitable growing territories. This is currently far in the future, but we are glad to be working with some exciting partners such as Royal Botanic Gardens, Kew and the Ethiopian Coffee Forest Forum to help communities become more resilient in the face of these challenges.

The topic on many people's minds is climate change, and how coffee will respond to it

What inspired you to bring out a book like this?

Union Hand-Roasted Coffee is celebrating its 15th birthday this year, which inspired us to look back at everything we've learnt about coffee. Educating people about great coffee has always been our aim, and this book seemed the perfect way to share some of what we've learnt over the years and help more people fall in love with great coffee. It's more than just a sourcebook. It contains our personal views on some of our favourite coffees, and the relationships we've built over the years and our personal take on the coffee world and how we approach roasting. It's an intimate guide to the world of speciality coffee.

Do you think there's a lack of information available?

Other than coinciding with our anniversary, there's growing interest in the world of speciality coffee. There's a proliferation of boutique coffee shops nationwide, with a growing customer base interested in quality coffee and seeking new things like different brewing methods, taste profiles and origins. This indicates there's an exciting group of customers with an appetite for speciality coffee who are keen to know more.

That being said, you don't need to know anything about coffee to enjoy the book – it's designed to be accessible and interesting for everyone. The world of coffee can seem a little intimidating to the uninitiated – much like the world of fine wine – so we wanted to create an accessible guide that everyone can enjoy.

What challenges are facing the London coffee scene? Where do you think it can develop?

The current watchwords for the industry are 'education' and 'experience'. When industries go through booms, it's common for people to try and capitalise on the wave of popularity, and coffee is no exception. We see many people, who after a couple of years working as a barista, want to get further up the supply chain and roast their own coffee. With so much literature (good and bad) out there on the Internet, traditional apprenticeships are declining and it's too easy for people to sell themselves as master crafts people without really having the practical experience, much as reading cookery books won't turn you into a masterchef!

After observing this happening, we realised that there was no easy way into the industry for enthusiastic people who want to learn, so in addition to creating this book, we're shortly going to open a new coffee roasting centre and training academy called Campus.