The Lowdown on Long Blacks

Australians love a good milk based coffee, there’s no two ways about it. In their annual coffee report, Square has listed the top 3 coffee orders in the country to be the Flat White, Cappuccino & Latte. Baristas are more in tune to the quality of milk than ever, and with more elaborate latte art designs showing up on social media, we don’t think that this trend is going to slow down any time soon.

This begs the question, where’s the love for black coffee drinkers? With Long Blacks accounting for just under 10% of coffee orders, we want to spend some time with you in understanding why this quiet little menu item should appear more on weekend brunch spreads and barista dockets at your cafe.

Breaking it down

What makes a long black? Simply put, a long black consists of hot (not boiling) water with a double espresso extracted on top. This creates a drink that’s still strong and flavoursome, and more easily enjoyed than it’s undiluted cousin, the espresso.

You might be asking, why would we want to do that? Ever had a shot of cordial before you water it down? Enough said. Even though it’s only made up of two ingredients, it does take some skill, practice & finesse to get things right.

How we do it at Gabriel Coffee

  • A ceramic cup with roughly 150ml capacity - a regular dine in for the folks tuning in at the cafe.
  • 80 grams of water @ 75 degrees (yes seriously, we’ll get into that below) - this can be hot water from the machine topped with cold water OR water from a temperature programmable kettle.
  • Double espresso extracted on top, served immediately.

Taking care of your tastebuds

At most cafes, boiling water coming straight from the machine checks in at over 90 celcius, regardless of takeaway or dine in, it's a pretty scary thought.

A study by the US National Library of Medicine found that almost all participants concluded that anything over 65 degrees was considered to be ‘too hot’ and that the ideal temperature was between 60-64.

Not only does a scalding hot coffee mean you might get burnt, but the excess heat may also have an effect on the flavour compounds from the espresso you extract!

We dive into this further by running some basic taste tests relating to when cool water should be added to a long black and how it affects flavour.

Team tests

Our Head Trainer Josh prepared 2 long blacks for a blind comparison with some of our team members. Since we've established that a long black should not be boiling hot when served, having an understanding of how we as coffee drinkers may perceive flavours differently in a long black depending on how it was prepared presents an interesting case for how you should prepare coffee at home or for your customers at a cafe.

In this exercise, Cup A had cold water added to boiling water before extraction, whereas the water was added after extraction in Cup B. The crema on both cups were then stirred to ensure visual consistency before being served.


After waiting for a couple of minutes, the temperature had cooled to roughly 65 degrees before tasting. The results of the test shocked those of us who have been massive proponents of adding cold water first before extracting espresso.

Firstly, we expected there to be a noticeable difference between cold water before and after the shots were extracted. In Cup A (cold water added after extraction),  we did notice that the samples tasted nicer at the start but lost some sweetness and flavour as it cooled after several minutes.

In Cup B (cold water added before extraction), samples stayed tasting nice for much longer as they cooled, retaining more aromatics, brightness and juicy body.

What this suggests is that with Cup A, when espresso is extracted over the too-hot water, even for a short period of time before cooling with cold water, it will increase the speed in which aromatics evaporate off. We understand that this is a basic sensory test, so to know for certain we would probably need some very fancy, high tech lab equipment, but we can surmise there is a strong correlation of high temperature and flavour drop off.

We also performed a test with a control cup, boiling water straight from a machine with a fresh espresso extracted on top. In a nutshell, this confirmed our initial suspicions, being far too hot to sip let alone identify particular flavours. As it cooled, many aromatics were lost and the mouthfeel felt somewhat dry.

Our Top Tips

We at Gabriel Coffee we recommend adding cool water before the espresso, this is especially the case if you are brewing with our Single Origin coffees. It provides a more palatable and delicate experience, and is a great way to train your tasting abilities.

But try it for yourself, before you start brewing your next long black, we want you to have a think - when do you add cold water? Is it before or after extraction? Try doing a side by side tasting for yourself or with your team and understand what differences there are and how this can up your black coffee knowledge and skills.