Brewing Guide - Espresso

How we Roll…

One of the hardest brews to perfect and always a moving target with so many variables in play, but also one of the most rewarding when done right.  

There are many factors involved in producing a good cup of espresso and it's not all about the machine.  In fact, the best advice for anyone who is looking to make improvements in their coffee making is to purchase a grinder, or a better one!  We are constantly seeing evolutions of grinders paving the way for better extractions, more consistent grinds and we don’t see this stopping anytime soon.

So you want to make espresso like us?  Read on!

Fresh Roasted Coffee

Seems obvious but if you don't start with a great fresh product then it doesn't matter how good your coffee equipment is.  Store your fresh product in a cool dry place and squeeze out any air; no fridges, no freezers please!

Equipment

We like to single-dose using a grinder with minimum retention, currently this is an EK43, of recent fame.  This may change, but for the moment it does the job well, very well.  We also use VST baskets as a rule, currently the 20g size so we can get a larger double shot while still maintaining our expected extraction yield.  We have various scales knocking about, but you can bet your grandma we will be weighing our ins and outs to achieve the best, consistent results.  However, we also use an on-demand grinder for our house blend, but we dial-in twice a day before and during service and adjust the grind constantly to take into account humidity and temperature changes.

*A Note on Grinder Adjustment

Grinder adjustment should be checked each time you make a coffee.  The grinder adjustment along with the coffee tamp determines how quickly the coffee is extracted i.e. how quickly the water flows through the coffee.  Think of it like grains of sand - very fine grains restrict the water flow, large particles cause lots of gaps so the water flows through the coffee quicker (see coffee extraction below).

The Tamp

Once you have your ground coffee in your filter basket, it's time to tamp.  The correct tamp pressure is 10 -15 KG.  Practice with a combination of grind and tamp to achieve your 25 to 35 sec extraction (see below).  You can always use a set of bathroom scales to calibrate your tamp, the key though, is consistency.  

*Do you even nutate bro?!

This is a question of eternal debate here at Rave HQ, and a point of contention between all of us. Nutation during tamping will affect the grind you use, effectively forcing you to use a coarser grind to achieve similar extractions as your non-nutating brethren.  Whatever you choose, stay consistent and stick with it.  

Coffee Extraction

No matter whether we’re using an on-demand or our single dose grinder, we are aiming to get our coffee from puck to cup in 25-35 seconds.  With the advent of refractometers, lighter roasts and less fines in the grinds, we’ve found that the time is less important than previously thought (our extraction window used to be 25-29 seconds, quite a liberal jump!).  As mentioned earlier we use precision engineered VST 20g baskets using 20.5g (to within a one bean tolerance) to produce a beverage weight of 42g, no more triple rizzies up in here!  

If your extraction is too slow (over extracted) i.e takes more than 35 seconds throw it in the sink with a look of disgust, rinse your cup and adjust your grinder particle size larger/coarser.  Don’t waste your taste buds on a shot that isn’t even in the ballpark.

If your extraction is too fast (under extracted) i.e takes less than 25 seconds adjust your grinder particle size smaller/finer.  Again, don’t waste your taste buds, throw it away and wait to hit the targets, then taste and adjust.

Just a quick note - if you are using pre-ground coffee, well… shame on you, go and buy a grinder, a burr grinder at that!  I’m joking, kind of, well not really…

The reasoning behind it is this:  You cannot dial in your grind to take into account freshness, temperature, humidity or the pressure capabilities of your machine.  There is no perfect universal espresso grind, not to mention that once ground the coffee will stale very quickly.  This will render any attempts at a decent shot nigh on impossible.  We’ve all been there, but it’s not an ideal situation…Invest in a decent burr grinder as soon as possible.

So there you have it, hopefully by now you understand how we brew espresso, and maybe you’ve picked up some tips along the way.  

Next up, how to steam milk.  Coming Soon