When I picture coffee in my head I see the gooey, caramel coloured stream of espresso flowing through the spouts of a portafilter on an espresso machine, this can be referred to sometimes as the ‘mouses tail’ in the coffee industry. I have been calling it this since I first learnt about coffee 13 years ago. Among many factors for achieving this, the biggest is getting the grind setting just right. I see making coffee as a culinary art and like being a chef you can have the best ingredients, but use them in a way that can destroy them.
Although grinders can sometimes be the bane of my life, they are the most important thing to making a beautiful cup of coffee. The correct grind used for espresso most commonly will result in the 30ml shot taking 20 – 30 seconds for the water to extract through under pressure, from the time of pressing the button, so includes the pre-infusion. I say this is the perfect cooking time for espresso and will hopefully create a finished shot looking like a small guinness with a thick, reddish, golden bright crema sitting on top, this is the oils from the coffee.
The grind for espresso is very fine in texture, if you rub the grind between your fingers, it feels oily & leaves a little residue but also has a sandy texture. It does clump slightly as it comes from the grinder. I love the feel of tamping coffee, this is when you compress the coffee down in the portafilter, it should feel slightly spongey with some definite movement in there, to compact it. If it is too coarse it will not feel like this.
If the grind is too fine it will result in an over extraction taking longer than 30 seconds & over cooking the flavours. Too coarse results in under extraction, under 20 seconds, under cooking the flavours. So this is how the grind effects the espresso but the grind setting is also as important for all the other coffee brewing methods too. (Watch this space for a section of my website explaining in detail how to use each brewing method.)
As a standard rule the longer the extraction time (how long the coffee is left to infuse with the water) the coarser the grind, for example – the grind for espresso, being the finest and takes approx 25 seconds. A Cafetiere/french press being the coarsest (very gritty, dry grind) takes 3-4 minutes to extract.
I did the 2 day brewmasters course in Chelmsford a few years ago at the SCAE Speciality Coffee Association of Europe depo, We looked at the things to consider when making the perfect brew, we didn’t just rely on our own personal tastes but proved it with science also. This is a bit different from how strong or weak we like our coffee. I have my refractometer to test the extraction (earlier blog touches on this). Giving a reading of how many Total Dissolvable Solids are in the liquid (TDS Reading). The average coffee drinker will not need this information. All you really want to know is does it taste good, is it to your liking? To find your perfect coffee you need to be prepared to experiment, have fun experimenting with your grind, this will mean you need a good grinder, which you can easily adjust and gives a consistent grind. Different coffees will require a slightly different grind.
Things to consider with the extraction of your coffee –
- Good coffee for the method you are using it for e.g. is it a blend or a single origin, is it a light or dark roast?
- Freshly roasted coffee, can also be too fresh & gassy 1 weeks – 3 months is good
- Well stored away from – air, light, heat and moisture
- Freshly ground
- Correct grind setting for the brewing method you are using
- Water quality. Hard or soft?
- Water temperature
- Correct amount of coffee to water
- Turbulence – Stirred enough
By looking at these points and altering them accordingly, you will find your perfect grind and brew in no time.
