It is possible to make a perfect coffee-quality espresso at home with a little trial and error. Here are tips from a barista for those who own an espresso machine.
The coffee beans
Buy your coffee beans from a specialized supplier who knows the age of the beans and where and when they were processed and roasted. Fresher beans make a better espresso, which should be viscous and full-flavored with a good crema. Bad coffee will be thin and flat. Always buy whole grains. Fresh grain should be stored away from light and heat at a constant temperature. It is not necessary to store grains in the freezer. A cupboard away from a heat source will suffice, but use them within three weeks. Make sure the beans are stored in an airtight container.
Your bag of coffee beans should have a roast date on the back. The beans should be used between four days and three weeks after roasting for optimal flavor. You don't have to be a professional to make a good espresso.
It is essential to grind well because it controls the extraction rate, which in turn affects the flavor. If the beans are ground too fine, a burnt or "ashy" flavor can result. If ground too coarsely, the espresso will taste watery and thin, as the water will pass through too quickly without extracting all of the coffee's aromas and oils. Paul describes the perfect texture for an espresso grind as "like flour with a little salt or sand". The ground coffee should clump together a bit when you squeeze it (but not too sticky). For filter coffee, the ground particles should look more like breadcrumbs. It is therefore important touse a coffee grinder electric or manual with grinding adjustment.
Clean and dry
Make sure there is no moisture (or old coffee beans) in your filter and porter basket. If the coffee comes into contact with moisture, it may start to extract too soon. Use a tea towel to wipe down the parts.
Serious baristas should invest in a tamper to compact their coffee evenly in the basket. Fill the basket about three-quarters full with ground coffee. Tap the basket on your bench to "collapse" the coffee and ensure the basket fills evenly. Add more coffee and let it settle until it is full, but not too full.
Pack the coffee: Paul grips the tamper like a doorknob and leans on it from above with a straight arm, "a weight of about 15 kg is ideal. If you turn the basket over after tamping, the coffee should stay in place.
After tamping, the basket should be about four-fifths full. If the coffee is too hard against the shower wall of the machine, you may get an uneven extraction; too far and the espresso may taste like coffee grounds. Paul uses the analogy of a watering can: water poured from too high a height will hit the ground (the coffee) with too much force and turn it over, producing coffee grounds.
your machine by running water through it before making your espresso.
Make the espresso.
Different baristas use different rules to ensure consistent, well-balanced espressos. Some, like Marco De Sousa Rosa, the 2017 French champion, advocate weighing both the dry coffee and the final wet espresso. According to De Sousa Rosa, a good "brew ratio" is about two parts dry coffee to three parts wet espresso. So 20 grams of dry coffee grounds should yield a final espresso of 30 to 40 grams, depending on your taste.
Paul's rule is to go by volume: "30 ml in 30 seconds". Espresso cups typically range in size from 60 to 90 ml, but Paul's ideal dose is 30 ml. If your machine takes longer than 30 seconds to produce a 30 ml shot, your grind is probably too fine and may taste burnt.
(Note that Paul recommends playing with your grind before anything else, you can also try changing the extraction rate by varying the amount of dry coffee you use. Less coffee will result in faster extraction and vice versa).
Signs of good coffee
Initially, the machine will deliver drips before a steady stream of espresso. The fresh coffee will be slightly viscous and almost seem to rise due to the oils in the beans.
Your 30ml espresso should have a nice creaminess on top. This is the lighter, fluffier substance on the surface. The crema looks like tiny bubbles and is reddish-brown or nutty in color and dissipates after a minute or two. The absence of cream is a sign that your coffee beans have passed the test.
Previously a tester of household appliances, I discovered a passion for coffee and the Barista world 6 years ago. I now spend my spare time sharing my experiences with my community. I hope you will find some nuggets on my blog 😃