One espresso shot: 30ml +/- 5mL made from ground coffee, poured from one side of a portafilter.
Brew time: The time it takes from when the pump starts to when it stops, or from when it starts until you have the desired shot
Is your home espresso machine coffee not hitting the mark? If we can understand just 3 simple variables, we can easily start to create good coffee. Once we control these variables our understanding of our morning cuppa can reach a whole new level.
Time is directly correlated with extraction; however, it is not linear to extraction. What do I mean by this? You could have a 50mL shot that took 10 seconds to extract. The aim is to get the desired extraction within the desired time. However, the longer you brew and the longer the contact time of water to coffee the stronger the coffee will be (think tea brewing).
An espresso shot that is under-extracted will show flavours that are salty/sour and less of the deeper flavours that we enjoy, and if the shot is over-extracted, the result will be overly strong, dry and flat.
So, what’s the perfect recipe for you? This depends on what your drinking! Dark roasts should be brewed using a shorter time, and lighter roasts need a longer brewing time. This is where the fun of coffee comes in. Start experimenting and writing your recipe.
A 20-30 second extraction time is recommended according to the 2017 World Barista Championship Rules and Regulations. We would recommend a 28-30 second window gives the best flavour useful as a starting point. If it's not falling between this range, this is when you will check variable 2 and 3 (Grind and Dose).
Why can’t we adjust the grind, and keep it on that setting forever? Unfortunately, humidity can affect extraction time as coffee absorbs moisture from the air. Baristas will often be changing the grind size multiple times during the day from when they start serving coffee in the fresh morning air, to the heavy humidity that hits in by 8am.
We can’t talk about time, without talking about tamping. The reason for tamping is to provide resistance against the water, which creates the pressure used to extract the flavour. Mind-blowing right! So why is this important? Because if you're tamping your coffee grounds too hard/not hard enough this may be what is causing you're timing to be out. We want to press not too hard, and not too soft. Vague, I know, but just keep this in mind.
If you would like to learn more check out our Espresso and milk training with our cafe specialist. Perfect if your looking to become a barista, want to upskill your team, or just want to elevate your coffee at home.