Artisan Coffee School

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20/07/2016

Espresso – let’s keep it simple!

Hey coffee friends!

I hope you all feel inspired after reading my last blog and hopefully you got a chance to try out some new coffees as well as some different processing methods. This month’s blog is going to be about the most popular as well as the fastest method of brewing coffee. Yip, you guessed it, ESPRESSO. So let’s get down to it and talk about the basics that so many baristas get wrong.

When I first started my journey as a barista I found it really difficult to get my espresso to taste consistently good and I battled to completely understand its complexities. I knew that I needed to put finely ground coffee into the basket of the portafilter and that I had to tamp the coffee (compact the coffee bed), insert the portafilter, turn on the machine and extract the espresso in a target time of 25 seconds (this was apparently the key number).

I learnt through trail and error that a finer grind would slow down the flow and a coarser grind would make the flow faster, but there were no basics rules to follow that I knew of and that made me seriously frustrated. From then until now I have been busy geekly learning about all things coffee and thought I would share some key points when starting out with espresso.

There are three main pillars to making a great espresso and these need to be followed to ensure a perfect extraction every time. Here they are:

Dose = The amount of coffee we add to the basket (this should always be as accurate as possible by using a scale, such as 20grams)

Yield = The total weight/volume of espresso that is extracted (a scale is required and accuracy is of key importance)

Extraction time = 25-30 seconds. Extraction time is all about the contact time between the ground coffee and water – too short an extraction time and this will result in an under extracted shot, which will be pretty acidic. On the flip side, too long an extraction time and this will result in bitterness. Every coffee reacts differently so extraction times will differ accordingly.

When making espresso we stick to a brew ratio (coffee to water ratio), which we also like to refer to as an Espresso Brew Formula or EBF. It looks something like this:

1:2 EBF (Espresso Brew Formula)

In simple terms, 1 part coffee to 2 parts water (1:2). So let’s create a recipe and begin the process.

RECIPE:

– 20g coffee (freshly ground into the basket)
– 40g espresso (extracted volume/weight)
– Time: 25-30 seconds

You may be wondering, ‘how do I adjust time!?’. Good question! If you were to imagine two glasses, one with pebbles and the other with sand and water was poured into both glasses, which glass would have the water hitting the bottom first? I’m sure we all agree it would be the glass with the pebbles due to the larger gaps. The same concept applies to espresso. So if we added our ground coffee to the basket and tamped (compacted the coffee perfectly level) as per the above recipe, then extracted the desired yield and got a total extraction time of 15 seconds then this would be classified as an under extracted shot, which did not fit into our desired extraction time bracket.

So how can we get our 25-30 seconds? Well just like the sand and pebbles example above, we can adapt that to our espresso. A finer grind will slow down the flow of water, which will add more time onto our extraction resulting in a well-extracted shot. This may take several adjustments to hit the target but once you become one with the coffee it will be like second nature.

By following this formula it will ensure that your coffee to water ratio is consistent, which will result in a cup of deliciousness. The amount of ground coffee must always be consistent, the amount of espresso extracted must also be consistent and time is the only variable. If you find your shot to be a bit on the acidic side then fine up the grind to extend your extraction time, this will bring out a bit more bitterness, which will balance out the flavours.

One point to remember is that every bean will react differently dues to roast degree and bean density but if all the above points are followed as accurately as possible then I can assure you that you will have a great espresso every time!

There are so many points to fine tune when making espresso such as cleanliness, tamping technique and distribution of coffee and I will be talking about that in the next blog. For now, get to your machines and adapt all these steps and discover the beauty of espresso.

Cheers
Dean Mackay

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