Mug shot: The magic unpacked

Misunderstood: the elusive double ristretto.
Misunderstood: the elusive double ristretto. Photo: Matt Holden

It started with a fairly innocent tweet - Can Sydney make a magic? While it didn't quite provoke a twitterstorm, it did cause a couple of tweeps to speculate on what ''a magic'' might be, which in turn earned a couple of grumpy barista rebukes along the lines of, "Oh, no. Not this again. For the last time, a magic is a …''

Well, for the last time: a magic is a double ristretto - about 45ml of syrupy espresso - topped up with milk in a 150ml tulip cup (or is that 120ml?)

A magic is a little less milky, a little more coffee-ish than a latte. It's what New Zealanders call a flat white (although some New Zealanders say a flat white is a double espresso, not a double ristretto). The story goes that it was dubbed the magic at Ray in Brunswick some time back in the early 2000s: it's Melbourne's gift to the coffee world. Just as tasty is the piccolo - a single espresso shot topped up with milk in a 90ml glass.

Part of what makes a magic - or any milky coffee - so magic is the creamy mouthfeel of well-textured milk. In theory, texturing milk is pretty straightforward, says Australia's reigning barista champion, Matt Perger, of the St Ali Family: all you're doing is heating the milk and introducing air to create very small bubbles of fat and protein, called microfoam.

The skill is in knowing when you've stretched it enough, and in getting the right mix of textured and flat milk in the cup.

Heating the milk also causes suspended lactose - a sugar - to dissolve, which is what makes the milk taste sweet. We don't perceive suspended lactose as sweet but we do perceive dissolved lactose as sweet.

Perger says the balance of temperature and flavour in textured milk is found between 60C and 63C - any hotter and you start to denature the milk, any cooler and customers complain. But Perger says milk tastes sweetest at around 45C - lukewarm!

What about the double ristretto? According to Perger, once you've dialled espresso shots into your coffee machine and grinder, you can't make a ristretto; you'd have to start over and dial in a finer grind. Baristas fudge it - either by packing more coffee into the portafilter, or pulling the shot short, effectively under-extracting the coffee - not always great to drink black, but it works a treat with milk. Bring on the magic.