"Welcome to Five Senses Coffee"

It’s safe to say that in our industry, Australians are refocusing their attention on the intricacies of classic brewing methods. I recently returned from my year in North America, inspired and ready to tackle brewing parameters, only to find I’m not the only one with new drinking habits. Just like espresso, black coffee results are often based on subjectivity; there are so many factors that we can attribute to a quality cup. With the Extract Mojo ™ system (EM) now available, we jumped at the chance to take a more calculated approach to our brewing explorations.

The EM utilises a refractometer which is calibrated specifically to measure the % TDS (Total Dissolved Solids) in coffee. Once we are able to measure this number accurately, and combine it with water and coffee weight, we can then calculate our extraction yield. These two numbers (% TDS and extraction yield) are very important when it comes to standard brewing parameters. Based on widely accepted research and Gold Cup standards, we are aiming for an extraction yield between 18-22%, with a %TDS range of 1.15 – 1.35 for optimum brewing results, better known as the ‘sweet spot’. Basically, anything outside the ‘optimum’ box will, in theory, show signs of under- or over-development. There will always be exceptions to the rule, but for the most part, this particular calculation is spot on.

What exactly does this mean? This information allows us to continually calibrate our brewing devices and grinders to achieve the best possible extractions. For example, if I am attempting to make a French press coffee (plunger), I would enter the amount of water I intend using and the EM software will calculate the exact weight of coffee needed. Once I’ve completed my brew, I can measure the resulting %TDS to see how close I am to the desired extraction yield. The software will chart my results on a coffee-brewing control chart in real time, making it easy (with experience) to see what adjustment is needed, often starting with particle size. Bottom line — less trial and error and more calculated results. It would certainly be a worthwhile experiment to trace the results as a particular coffee ages too.

The more chance I get to play around with the EM, the more I realise how many experiments could be validated by this piece of equipment. It really could be an invaluable tool for any café trying to create an exciting and dynamic black coffee programme. Continually changing origins and brewing methods would require regular calibration, so having an EM on hand would come in very handy.

Keep an eye on this space over the next couple of months as I take a closer look at some of the more popular brewing methods coming back into fashion.