Firstly, welcome, everyone, to the new M5 Espresso Lab Blog. It is my hope that this page can be used to talk about new coffees and roasters I'm bringing into the shop, new techniques for brewing, and other coffee-oriented news.
For my first post, I've decided to hone in on the most striking feature of our bar - the black two group Slayer espresso machine. Anyone who's taken a good look at the bar in most coffee shops will recognize that this is a fairly uncommon piece - in fact, ours at M5 is the first in Cincinnati. Slayer is a relatively young company in the world of coffee, and sets itself apart for a number of reasons. Firstly, the majority of espresso machine manufacturers are Italian, and their designers come from an engineering background. The same minds who brought you any number of Italian sports cars also bring you machines from Faema, La Marzocco, La Spaziale, Nuova Simonelli, etc. Slayer is different. Our Slayer was designed in the USA by Jason Prefontaine - a lifelong coffee roaster who found himself frustrated with the limitations of every commercial espresso machine on the market. He was not on a quest to create some feat of engineering - he simply wanted a high quality cafe machine that would bring out the body and complexity of filter coffee in a shot of espresso.
In order to understand the Slayer, you must first understand the basic mechanics of a standard, dual boiler espresso machine. Finely ground coffee is loaded into a portafilter basket - this basket has thousands of tiny holes, which, when hot water and 9 bars of pressure are added to the coffee bed, will allow espresso to flow through into the cup below. Standard machines (such as the La Marzocco Linea) have one boiler dedicated to espresso, and one at a higher temperature dedicated to steam. These machines are fairly simple - they operate at one, consistent pressure all the time, and the pump can simply be turned on or off. In more recent history, baristas discovered that allowing the coffee to "bloom" or preinfuse made for greater consistency and flavor from shots. Many companies responded to this by adding a preinfusion setting on their machines, which would briefly activate the hot water pump, flushing the coffee bed at full pressure, shut off, and then begin the normal ~25-30 second extraction.
While this standard "preinfusion" certainly helped, Prefontaine felt that it could be pushed further, and thus set out to develop a machine with a longer, low pressure preinfusion. On our Slayer at M5, our shots preinfuse for nearly 20 seconds, allowing the coffee bed to expand and release Carbon Dioxide, increasing the viscosity and body of the espresso and suppressing much of the acidity that many people associate with lighter roasted coffees. This is a result of the Slayer allowing the barista to dial in their coffee grind much finer than on a traditional machine. Smaller particle size results in greater extraction yields and a huge increase in flavor - espresso on a Slayer is not the red hot, bitter liquid many people have become accustomed to - it's sweet, refined, and exceedingly palatable.
Our goal at M5 is to showcase every part of our coffees' journeys from farm to roaster to the cafe. The Slayer allows us to highlight the beautiful flavors our roasters and farmers worked together to cultivate, and is just one step in chain of elevating your coffee experience.