Now that we have decided on the beans we want to run through our espresso machine, we need to know how to get the best out of those beans. If the actual coffee you run through your espresso machine is the most important factor in making the perfect espresso shot, then the grind size runs a close second. Let me start by saying that many factors will affect which grind number you will need every single time you pull a shot of espresso. A few of the variables include: differing espresso machines, different coffee bean blends and roast colors, different espresso grinders, the freshness of the beans, and even the weather. Because the coffee we provide to our customers is so fresh, the freshness variable is minimized. For the purpose of this blog, I will be strictly talking about pulling a double shot of espresso on our fully-automatic La Spaziale espresso machine. When pulling a double-shot of Double Espresso in our tasting room, I use a grind of 3.50 on our office grinder, while Espresso Maximo requires a grind between 4.0 and 4.25. The reason for this is the differing roast colors and the differing origin coffees of the two blends.
In general, an espresso grind should be somewhere in the middle of a drip grind and a really fine, Turkish grind. There is a lot of room in that range of grinds, so a lot of refining and practicing is necessary. You do not want it so fine that the grounds look like powdered sugar. You also do not want them so coarse that you can see large grains of coffee. I always recommend grinding the beans as you need them to ensure you create a thick crema.
How I pack the grounds into the porta-filter is a very important step in the whole process. First, I fill the grounds to be even with the top of the porta-filter. Next, I slide my finger straight across the top of the porta-filter to wipe away any excess grounds. If I end up with some extra grounds, I save them, and use them in my next shot of espresso. With the hand tamper, I push directly down on the grounds and turn my hand roughly 180 degrees to lock the grounds into a nice, solid pack. The industry standard is to push down with thirty pounds of pressure, but it is really all about feel. I always prefer to use a hand tamper as opposed to using the built-in tamper on an espresso grinder. Never load the grinds into your porta-filter and stick the porta-filter directly into the espresso machine without having first pressed down on and turned the grounds into the porta-filter.
On a fully-automatic espresso machine, the perfect double shot of espresso should take about 18-22 seconds. This time allows for the correct amount of extraction from the grounds, and allows time for a thick, heavy crema to develop. When the espresso shot is brewing, the flow of the coffee should look like a mouse's tail. You do not want the coffee flowing out rapidly or barely dripping out of the porta-filter.
Here are a few troubleshooting tips to help make your espresso-brewing experience even better. I am under the assumption that your machine is releasing the correct amount of water for a double shot. A double shot typically yields 2 to 2.5 ounces of coffee. Remember that I am talking about a fully-automatic espresso machine, so these numbers may differ drastically from your home espresso machine. If my double shot is taking less than the 18-22 seconds to brew, and the coffee is flowing out rapidly, then either my grind is too coarse, I do not have enough coffee in the porta-filter, or I am not packing the grounds tight enough into the porta-filter. If the time of the shot is really short (i.e. 5-10 seconds), then it is surely because either the grind is too coarse or I did not put enough coffee into the porta-filter. If I think the grind is good, and I want to add a few seconds onto the brew-time, I will pack the grounds just a little tighter. If my shot is taking way longer than 22 seconds, then either my grind is too fine, I have too much coffee in the porta-filter, or I need to pack the grinds a little looser in the porta-filter. If the espresso shot is taking way too long (i.e. double the ideal brewing time), then first I tweak the grind to a coarser setting. If it is pretty close to the ideal brewing time, then I try playing around with the tightness of the pack.
Hopefully these tips have helped in your mission to create the best possible espresso shot at home or at work. Coming up soon, in my final blog about espresso, I will give a brief tutorial on how to create the ideal steamed milk for lattes and cappuccinos. I will also cover how to make some of the most popular espresso-style drinks. Until next time, stay caffeinated!