How To Brew The Ultimate Espresso
Espresso.
The magical method of percolation that involves passing water through a fine metal filter, commonly known as a portafilter and basket. The marvel of the espresso machine lies in their ability to apply high pressure to force water through a tightly packed bed of coffee, which leads to proper percolation and a perfectly balanced extraction. When the coffee is ground finely, as it is for espresso, extraction happens quickly. The smaller the coffee grounds, the greater the surface area, which streamlines the flavour extraction process. The high pressure in espresso machines also helps water penetrate the inner cell walls of the coffee grounds, capturing elements that gravity alone would struggle to reach. The end result? A rich and concentrated embodiment of coffee, with a unique body and texture that can't be replicated by any other brewing method.
However, achieving a truly exceptional espresso requires mastering the art of good extraction. While it may sound simple, espresso poses a challenge due to its intensity. A well extracted espresso boasts a harmonious combination of aromatic and taste compounds; bitterness, acidity and sweetness.
When extracting espresso, acids are released first (which is why under- extracted espresso tastes sour.). Sweetness comes next, characterised by a good body, aroma and a chewy texture. Finally, the slow-dissolving bitter compounds make their appearance providing balance, but beware, they will over power the cup if the shot is over-extracted. The aromatic qualities of espresso are an essential part of its uniqueness, and they largely stem from the coffee roaster and coffee farmer rather than the barista. While it's nearly impossible to manipulate the espresso shot to achieve a specific aromatic profile, the taste profile can be adjusted to enhance the perception of those aromatics. For example, the barista can dial up the acidity to bring out citrusy aromatics of a Kenyan or Colombian coffee.
HOW TO BREW MIND BLOWING ESPRESSO
Now is the part you have been waiting for; how to brew mind blowing espresso like a boss. But before we dive in there are a few non-negotiables that have to be addressed before we get to the recipe. There are a few pieces of essential equipment that if you haven't got already, you're going to need. It's like when a recipe calls for rosemary and you omit it because you don't think it really needs it (or you can't be bothered to go to the supermarket and get some) - believe me, it needs it!
DIGITAL SCALES
Similar to a burr grinder, you simply can't achieve espresso greatness without a set of scales. The coffee scoop or spoon way of measuring out your coffee is a relatively typical error that most people make. If you get it wrong by only a few percent, it can have a massive impact on the entire cup. It's not a good idea for a number of reasons. The weight of a spoonful of coffee beans will vary with each spoon since coffee beans are very light and you will never pick up the same number of beans in a scoop at once. Dose control (we'll talk about this a bit later on) is essential. A spoon cannot be measured in terms of volume using a consistent scale, as different spoons will hold different amounts; 5g or 7g or maybe more. So if you continue down that road, the amount of coffee you use each time will vary greatly depending on the spoon you use. So do yourself and your coffee a favour, and get some scales.
TIMER
Regardless of the brewing method you use, the length of time it takes for the water to flow through the coffee is one of the most crucial factors in producing a flavourful cup. For this reason, you're going to need to know how long your coffee will take to brew. Yes, you can just use the stopwatch function on your phone, but the easiest way is to invest in a digital scale with a timer built in - it's simpler and more convenient.
NEEDLE DISTRIBUTOR
Named after its developer John Weiss in 2005, the Weiss Distribution Technique (WDT) was created to address the issue of grinders generating excessive clumps. WDT serves as a distribution method specifically designed for making espresso. By using a needle distributor, the barista stirs the coffee within the portafilter. This stirring action effectively disperses any clumps and ensures a uniform density of coffee throughout the puck, reducing channeling and improved, consistent extractions.
A good way to think about it is to imagine a river. Now place some rocks in that river. The water can’t flow through those rocks and has to pass around them. This is exactly the same for brewing espresso. If your portafilter has ‘coffee rocks’ in it, the water isn’t going to be able to penetrate and is going to find it’s way around them, finding the path of least resistance. This causes channelling, under and over extraction and an unbalanced shot. Distributing your coffee properly before tamping will reduce this enormously.
WEDGE DISTRIBUTOR
This tool, when combined with the WDT technique will help you on your way to achieving consistency when prepping your portafilter. The wedge shape evenly distributes and flattens the ground coffee into the basket before you compress it with your tamper.
TAMPER
The coffee is then levelled and compressed by using a flat tamper. When the coffee bed is not level, the water will flow through the path of least resistance, resulting in both over-extraction and under-extraction occurring on different sides of the bed during the brewing process.
PUCK SCREEN
Although it’s not essential to use a puck screen to get outstanding espresso, it does help. Especially if you are suffering with channelling. The puck screen evenly distributes the water flow, leading to a more balanced shot. Ensure you buy a stainless steel screen and be aware that they come in a variety of sizes so it’s crucial to match the size of your screen with your portafilter.
THE RECIPE
First we have to start with your dose. I recommend a dose of 18g - 20g. The exact amount you use will depend on the size of your portafilter basket. A little side note here, some baskets (like the VST baskets) will come with a reference on them to indicate how much coffee should be used. If the basket is overfilled, you'll notice that the portafilter won't lock into the group head. On the other hand, it's important not to under-fill the basket either, as this creates excessive headspace above the coffee, resulting in a soggy cake and inconsistent flow rate.
Like I said in the previous chapter about grinding, it's impossible for me to say on what setting you need your grinder, or how fine or coarse you should be grinding at. This all comes with knowing your bean, knowing your grinder and knowing your espresso machine.
As a general rule of thumb, the ideal consistency for espresso is fine and powdery. The grounds should have a smooth texture with a consistent particle size. They should have a uniform appearance without any large or uneven pieces. When you touch the coffee grounds, they should feel slightly gritty and powdery, similar to sand. If you rub the grounds between your fingers, it should leave behind a slight oily residue.
Now you've nailed your dose, the next element is portafilter prep.
You've surely hear of the military adage,
"Proper Puck Preparation Prevents Piss Poor Performance"?
Not a truer word can be said. Spend time preparing your portafilter and reap the rewards of a beautifully extracted cup. First up is distribution. When the coffee is ground and falls into your portafilter, more often than not there will be some clumping. We need to get rid of these clumps and we achieve this by distributing the coffee grounds evenly throughout the basket.
Anthony Douglas, winner of the 2022 World Barista Championships (WBC) believes that the Weiss Distribution Technique is the most effective distribution method to use.
"It's the best distribution method that I have used because it's the only
technique that evenly distributes ground coffee from top to bottom, as well as
side to side. I've experienced the best results with this method."
To begin with, it's important to consider the type of tool you are using, specifically the size and length of the needles. I recommend using thin needles, no wider than 1mm to ensure the grounds are evenly distributed. Additionally, its crucial that all the needles reach the bottom of the portafilter basket in order to achieve consistent distribution throughout the entire basket. If the needles are too short, only the surface of the puck will be affected, potentially leading to channelling and uneven extraction. It is possible to overdo the distribution by being too aggressive. It's always best to use a funnel or guard when distributing as not to spill any grounds and stir in a controlled manner to achieve optimal and repeatable results.
You've de-clumped your the grounds in your basket so they're a uniform size, so what happens now? You're going to need to slightly flatten the mound of grounds ready for tamping. If you tamp straight into the distributed grounds theres a chance, as you depress the tamper, some of the grounds fall out of the basket. This will alter your dose and ruin all the prep you've done so far. You'll eliminate this by using a wedge distribution tool. This tool will flatten and distribute the grounds around the basket, leaving you with a flat surface on which to tamp onto. Tamping is a critical final step that involves compressing the coffee grinds into a uniformly distributed puck.
During extraction, water naturally seeks the path of least resistance, making it essential to tamp the grounds thoroughly and evenly to achieve a well-balanced extraction. The tamping process prevents water from easily escaping through the group head, allowing it to absorb the coffee's flavours before exiting the group head spout. A.K.A coffee extraction.
To consistently achieve a balanced extraction, it is important to maintain consistency in your tamping technique. The evenness of the tamp is always more important than the force applied.
When tamping, it is crucial to have proper form. Begin by positioning your tamping hip towards the counter. Keep your wrist straight and your elbow bent at a 90-degree angle, as this posture enhances control and prevents wrist strain injuries. Hold the tamper as if you are grabbing a doorknob, ensuring your thumb and index finger touch the base. This grip provides two points of contact with the tamper base, promoting a level bed of coffee grounds. When beginning the tamping process, apply pressure gradually, starting with approximately 15 pounds. This gentle pressure helps shape the coffee grounds into a cohesive puck. Once the puck is formed, increase the downward force to create a compact and robust puck. Applying around 20 pounds of pressure is about industry standard. Remember, technique matters more than sheer force, as excessive force can strain your wrist and potentially lead to over- extraction as you’ll have compacted the coffee grounds too much.
Before your muscle memory takes over, you can learn to apply the correct amount of pressure by standing on a bathroom scale while pressing down on the counter and watching your weight decrease. Alternatively you can invest in a calibrated tamper (like the Concept Art Technic Dynamometric Tamper). When you have decided on the right amount of pressure for you, simply lock the central screw in place and tamp your puck. When you reach the desired pressure, the tamper will automatically trigger a click release to let you know this pressure has been achieved.
As you lift the tamper, employ a twisting motion to ‘polish’ the puck. However, take care not to twist while pushing down, as this can disturb the packed coffee.
Finally, examine the puck closely, ensuring there are no gaps or loose spots, and wipe away any stray grounds that may have spilled around the edges of the portafilter. (I like to refer to this final step as 'blessing' the coffee before it goes into the espresso machine to create a 'heavenly' shot of espresso!) It also worth noting there that not all tampers are the same size and range from 49mm to 59mm. I would advise measuring your portafilter basket first before purchasing your tamper. Once you've got the diameter of your basket, look for a tamper that is slightly smaller to it will fit inside. For example, if your basket is 54mm, you'll need to look for a 53mm tamper.
Now comes extraction.
The Main Event.
The Centrepiece.
The Showstopper.
Firstly you want to run some water through the group head to maintain water temperature and give your group head a quick clean. 2 seconds will be fine, but if your machine has been sat idle for a while, give it about 8 seconds. Next, place your perfectly prepared puck into the group head, grab your scales and cup and place them underneath the spout.
Zero off your scales, prime your timer and go, go, GO!
As the extraction commences, a magical transformation occurs. The espresso flows gracefully from the spout of the portafilter into the waiting cup. This black gold cascades smoothly, forming a steady stream, while a rich, velvety layer of crema begins to form on top of the surface of the espresso. The air is saturated with the rich aromas of freshly brewed coffee, this intense fragrance fills the space, captivating the senses.
What you are aiming for here is a ratio of 1:2 over 28 to 30 seconds. Lets assume you have ground 18g of coffee into your portafilter. You then want 36g of espresso in your cup. Notice how I’m talking in grams and not millilitres. That’s because volumetric measurements like millilitres are pretty much useless when it comes to coffee, especially espresso, for one reason…
CREMA
The foam that sits on top of your espresso that is related to how fresh the coffee is. It is some of the carbon dioxide that was trapped inside the coffee beans during the roasting process that has been extracted and is now sitting on top of your drink.
The fresher the coffee is, the more crema you are going to have. So if you are looking for a fixed volume of 50ml, with a very fresh coffee, more of that volume is going to be gas and less liquid, compared with another coffee that has been rested longer. This is why I recommend weighing out your shots, because this way you will really understand how much liquid has been pushed through the portafilter, and is one of the most critical elements to control if you want repeatable espresso. You will be surprised by how much different a few grams more liquid will make when pulling a shot of espresso. For example, going from 32g to 36g might be the difference between a weak, sour espresso to one thats more balanced and more complex in flavour. This is why it’s so important to use scales when making espresso. Such a small change can have a massive impact.
TROUBLESHOOTING
So what happens if you’ve done all of the above but your espresso gushes out of the spout like a waterfall, or drips out like a leaky tap?
The first thing to check would be your grind size. As a general rule, if your espresso shots are running too fast you need to grind finer. If it’s too slow, then you need to grind coarser. After making a change to your grind size, it’s important to purge a few grams of coffee left from your previous grind size. This could be as little as 5g, but as much as 20g depending on your grinder.
When timing your shots there are two schools of thought; starting the timer as soon as the pump kicks in, or starting it when the first drips of coffee appear. In my opinion, the timer should start as soon as the pump kicks in as this will also take into account the pre-infusion phase of espresso.
What is pre- infusion?
“It is the continuous introduction of water at a low pressure (3 bars or line pressure, for example), until static pump pressure is applied to the brewing process. The goal of this continuous flow of water at a low pressure is to fully saturate the coffee puck prior to beginning the brewing process.”
If you are finding that your shots are still too fast even at the finest grind setting of your grinder, you can slow them down by slightly increasing your dose. Just be sure to increase your output weight to keep the 1:2 ratio. And remember that your grinder isn’t ‘set and forget’. Differences in coffee bean type, age, temperature, humidity can affect the timing of your shots, so you will have to make small adjustments to match the change in conditions.
For example in the coffee shop, the first shot I pull in the morning (typically at yesterday evening's settings) will be different to the shot I pull at lunch. This is
down to the temperature of the coffee beans in the hopper, the ambient heat from the grinder, the temperature of the coffee shop increasing, and a whole list of other things. So its' important to remember that you should always be measuring your shots to keep your espresso consistent.
CHANNELLING
Channelling can significantly harm your coffee extractions. When water is pressurised, it naturally seeks the path of least resistance, which in espresso brewing is the water passing through the coffee grounds. Ideally, with a uniform grind size, even distribution, proper puck preparation, and consistent water dispersion, the water should evenly and gradually form a pathway across the coffee puck as it dissolves and washes away the coffee grounds.
However in the real world, any flaws in these areas can create channels. These channels lead to over extraction of the closest grounds and under extraction of the grounds further away. The resulting shot is muddy and unbalanced, exhibiting the characteristics of both under and over extraction. The ultimate way of monitoring channelling is to use a naked or bottomless portafilter. This type of portafilter eliminates spouts, providing a clear view of water through the puck. A perfect shot will show the first drips of coffee forming evenly across all the holes. From there, you might see a few drops of espresso, or multiple streams for a brief moment before they converge into a continual funnel of deliciousness coming down from the centre. However, if you’ve got an off-centred stream, gaps in the holes, spurts of water, or premature blonding in one section of the basket you’ve got a problem. This could be uneven distribution of the coffee grounds, improper tamping technique or channelling within the puck.
If you don’t have a bottomless portafilter, you can examine the puck after pulling your shot. Damaged pucks with large craters or even tiny pin holes throughout often indicate channelling.
OH PUCK!
The humble coffee puck. The circular disc of joy that remains after a successful espresso extraction. When everything goes according to plan you’re left with a dry(ish) disk that resembles a hockey puck. When you’ve completed your extraction, give it a few moments for the water to drain then remove the portafilter from your machine. Gently press the surface of the puck - it should feel spongy, yet firm to the touch. Next, knock the puck out onto your counter, and if it stays intact, you’ve hit the dose bullseye!
If your puck feels as hard as a rock then you’ve dosed too high. A rock hard puck indicates insufficient expansion during the shot, resulting in a shorter extraction time. This can also place unnecessary strain on your espresso machines gasket and shower screen, which is definitely not ideal. On the other hand, if your puck is watery and lacks structure, you’re dosing too low. An insufficient dose will leave you with a wet, sloppy and soupy looking puck, which may not taste horrendous, but will be messy and leave you with a lot more clean up to do!
To sum everything up, make sure (if you’ve not got them already) you’ve got your digital scales, timer, needle distributor, wedge distributor and tamper. Ensure you are paying close attention to your puck preparation, making sure that the grounds in your portafilter are evenly distributed and you are using proper tamping technique.
My recommended dose is 18g using a 1:2 ratio, but play around with what tastes perfect to you. You might find that 20g in, 40g out is more to your liking (remember to make sure your portafilter basket will take 20g though!) Or you might want to change up the ratio to 1:1.5 or even 1:3. Experiment and see what you enjoy the most.
IS IT THE MACHINE? OR IS IT YOU?
First you want to check the temperature of your espresso machine. If your machine has a display, it should read between 198°C and 202°C for your brew boiler and between 255°C and 272°C for your steam boiler. If your machine doesn’t have a display, or if you are using a single boiler machine, the pressure gauge should sit between 1.25 to 1.75 bars of pressure. Next, you need to test that your machine can build adequate pressure, and to test this, put the blind back flushing disc into your portafilter and lock it into the group head and engage your pump. Check the needle on your gauge and make sure it sits between 8 and 10 bars while the machine is building pressure. You also want to make sure that the needle is rising smooth and steady. Lastly is the flow rate of your espresso machine. You are looking for around 250ml of water in 25 seconds. Simply remove your portafilter from the group head, place a measuring jug underneath and run the pump to ensure your flow rate is correct.
If your machine passes all of these tests then that shows that your machine is just fine. So what happens now? A poor shot of espresso can come down to the coffee you are using, what grinder you have and what recipe you are following.
Your espresso is only going to be as good as the coffee you are using. When buying beans, look for beans that are 5 to 10 days off roast, don’t buy pre-ground, or coffee that doesn’t have a roast date on the bag. In regards to your grinder, ensure you have read chapter 3 on how to prepare your grinder for espresso.
Lastly, your technique makes a difference. Try to eliminate as many changing variables as possible, by staying as consistent as possible. Measure and use the same amount of coffee each time. Be consistent with your tamping and distributing technique, and aim for the output to brew between 25 - 30 seconds.