Watery Espresso: 11 Reasons Why and How To Fix It

Watery espresso is a fairly common problem when brewing espressos. Fortunately, it is fairly easy to troubleshoot this issue even as a beginner barista.

Some of the easy solutions to solve a watery espresso are to tweak your grind size, check your tamping pressure or change the brew ratio.

That said, after pulling espresso shots for the past 7 years, I’ve come to realize that there are more reasons why your espresso tastes watery.

In this post, I will share and deep dive into 11 reasons why is your espresso watery and how you can prevent watery espresso.

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At a glance: Watery Espresso (11 Reasons Why And How To Fix It)

What Is A Watery Espresso?

A watery espresso, as the name implies is when your espresso looks and taste diluted. 

Physically, you cannot see the three layers that make up an espresso. Namely, the Crema, Body, and Heart. Instead, espresso with watery consistency looks thin and the crema layer is almost non-existent.

In terms of taste and flavor, a watery espresso will taste like a weak and mild espresso with no depth of flavor. At times, it has a sour flavor profile which is unpleasant.

All in all, a watery espresso is not suitable for direct consumption or used as a coffee base for espresso-based beverages. 

11 Reasons Why Your Espresso Is Watery

While it is easy to identify a watery espresso, fixing the problem requires some troubleshooting. 

Here, I will share a comprehensive list of the factors causing your espresso to have a watery consistency. 

1. Under-Extraction

The main reason why your espresso is water is because of under-extraction. 

Under-extraction happens when you do not allow enough contact time between the water and the coffee grounds. In other words, the water passing through the coffee grounds is not extracting enough aromatic compounds and coffee oils from the coffee grounds. 

This result in more water component in your espresso than coffee compounds. And with a higher ratio of water in the espresso, the flavors of the natural acids present in the espresso will be less pronounced.

That said, under-extraction stems from a combination of reasons such as poor extraction pressure and coffee grind size being too coarse.

2. Stale Coffee Beans

If you are using old coffee beans which have most likely gone stale and rancid, the resulting espresso will be watery.

This is because of a chemical process known as oxidation.

When you expose coffee beans to the surrounding air, the oxygen present in the air will slowly react with the aromatic compounds in the coffee beans. Prolonging the exposure will eventually cause these volatile aromatic compounds to escape, resulting in flat-tasting coffee.

Do keep in mind that the oxidation process starts right after the coffee beans are out of the roasting drum. So, it is essential to store your coffee beans in optimum conditions to slow down the oxidation rate.

Ideally, you should use coffee beans that are 2 to 3 weeks from the roast date and finish them within a month.

Author’s Note: Optimum storage conditions for coffee beans are air-tight, low humidity, cool, and away from strong light sources. 

3. Coarse Coffee Ground Size

Coffee beans’ grind size can be a tricky aspect to master.

In this context, grinding your coffee beans too coarsely will result in watery-looking espresso. This is because the large sizes of coffee grounds create too much space between them. As you brew your espresso with it, you will quickly notice watery coffee from the machine.

So during espresso brewing, high-pressure hot water can easily pass through the bed of coffee grounds in the portafilter with barely any resistance.

As a result, this will shorten the time of contact between the water and coffee grounds. Too much water will be flowing through without sufficient time to extract the coffee’s natural acids and oils that form the espresso.

In other words, the espresso extraction time is too fast here!

4. Low Water Temperature

As we all know, the extraction of aromatic compounds and coffee oils from coffee grounds requires water. In the context of espresso extraction, it demands hot water within the range of 92^oC to 95^oC.

Using water temperature which is not hot enough will result in a lower extraction rate of the flavorful acids and coffee oils.

This is because higher-temperature water has higher extraction energy in comparison to cold water. For this reason, you often see cold-brew recipes involving a steeping time of up to 24 hours. Cold water needs a longer time to extract all the flavor compounds from the coffee grounds.

Fortunately, most modern espresso machines come with built-in PID temperature control that allows you to manually set the brewing temperature. All you need to do is to make sure to warm up the espresso machine’s group head by flushing it once or twice with the hot brewing water.

5. Incorrect Tamping Pressure

The coffee puck’s tamping pressure is another tricky factor to address. However, it is one of the more probable factors causing watery-tasting espresso shots.

If you tamp too hard, you may risk over-packing the bed of coffee grounds. Water from the espresso machine will not be able to seep through the coffee grounds.

Tamping too lightly on the other hand will cause the coffee bed to be structurally loose. As a result, these regions will be prone to water channeling.

Author’s Note: If you are unsure what 15 pounds of pressure feel like, press your tamper on a weighing scale. Familiarise yourself with the force that will give you 15 pounds of pressure. 

6. Wrong Tamper Size

Using the wrong tamper size is a sure way to get a watery espresso. 

Picture this. 

You have a portafilter of 58 mm in diameter filled with fine coffee grounds. And subsequently, you use a 55 mm wide coffee tamper to level and pack the coffee puck. 

Doing so causes uneven pressure distribution throughout the coffee puck. The area which is in contact with the surface area of the tamper will be densely packed. Conversely, the outer ring of the coffee bed will be loose and structurally weak.

As a result, high-pressure water from the espresso machine will easily seep through the weak outer ring of the coffee bed. The espresso you get will look like a watered-down coffee.

So make sure you get yourself a tamper size that matches your portafilter’s diameter.

7. Imbalanced Coffee Bed

Getting the right tamping pressure with the right tamper size is not all. The tamping of the coffee puck also has to be even and balanced. 

Uneven tamping of the coffee puck will cause two probable outcomes. 

First, the unbalanced tamping will not pack the coffee puck in the portafilter evenly. This means certain parts of the coffee puck will be much denser. As a result, when the high-pressure water hits the bed of coffee grounds, the looser sections will allow water to pass through easily.

Secondly, the coffee puck level will be uneven with one side slanted to the other. During espresso brewing, the extraction will be uneven and the thicker side will have a higher resistance. On the other end, high-pressure water can easily penetrate through and this will cause the espresso to be watery.

8. Incorrect Brew Ratio

Brewing your espresso with the wrong brew ratio will also cause your espresso to be watery.

The industry-wide consensus for espresso brewing is to use a brew ratio of 1:2. This means for every gram of coffee ground, it should yield 2 grams of espresso. 

On top of that, the process of brewing a standard espresso should be between 25 to 30 seconds. 

In summary, for 18 grams of coffee grounds, you should ideally yield 36 grams of espresso in 30 seconds. 

And so, if you are dosing too little coffee grounds into your portafilter, it cannot provide enough resistance during espresso brewing. As a result, water can easily break through the coffee puck and contribute to the watery taste of your espresso.

9. Wet Portafilter

A wet portafilter is a lesser-known culprit that will cause your espresso to look watery.

Dosing fresh coffee grounds into a portafilter that is wet will cause some parts of the coffee grounds to get in contact with some of the water droplets. Consequently, these spots will harden and become a weak point of the coffee bed even after proper tamping.

When the high-pressure water from the espresso machine gushes onto the coffee puck, the hardened spots will cause cracks in the coffee puck.

These cracks will open easy pathways for the water to flow through the bed of coffee grounds. And as a result, the espresso will look watery as too much water flows through the bed of coffee.

With this in mind, always wipe your portafilter dry before dosing in fresh coffee grounds for your next brew.

10. Low Extraction Pressure

Generally, espresso brewing requires an extraction pressure between 7 bar and 9 bar. However, coffee aficionados may argue that 9 bar pressure is the absolute pressure to pull an espresso shot. 

Low extraction pressure may stem from a number of causes:

1. Coffee grounds are too coarse resulting in water channeling.  

2. Espresso machine not generating sufficient pressure.

3. Insufficient tamping pressure leading to a loose puck. 

Hence, if you notice the pressure meter on your espresso machine dwindling below 7 bar fairly quickly, I’d advise you to first check and tweak your coffee grind size first.

If fine coffee grind size and proper tamping do not solve the problem, you may have to check your espresso machine’s pump system.

11. Poor Quality Espresso Machine

Unfortunately, not all espresso machines are built the same. 

Cheap espresso machines are usually associated with poor quality. And that is not all.

Cheaper espresso machines have difficulty maintaining optimum pressure and temperature for espresso brewing. With fluctuating pressure and temperature, the resulting espresso extraction will be imbalanced and sometimes watery.

Ultimately, you get what you pay for. That said, as you progress to a certain price point, the return on investment diminishes.

So, I do recommend mid-range espresso machines to start with. These espresso machines usually have decent-quality parts that ensure constant pressure and temperature throughout the brewing process.

Author’s Note: Between an espresso machine and a coffee grinder, I’d highly recommend allocating more budget to the coffee grinder. With a coffee grinder that gives consistently good grind size, you still can get great-tasting espressos with a budget espresso machine. The same cannot be said

How To Fix Watery Espresso?

Knowing the 11 probable reasons why your espresso is watery, it is now fairly easy to fix this watery problem.

Before brewing your espresso, here’s a simple step-by-step checklist on troubleshooting watery-tasting espresso.

Other Possible Ways To Troubleshoot Watery Espresso

After you complete the steps above, all that is left is the coffee grind size. So, to determine if you should grind finer or coarser, you should first brew one test shot. 

If the espresso is flowing out too quickly, you should tweak your grinder to a finer setting. Conversely, if the espresso flow seems slow, you should alter your grinder setting to a coarser setting.

A good guideline for proper espresso brewing is to achieve a yield ratio of 1:2 within 25 seconds to 30 seconds. This means for a double shot, you should aim to get 36 grams of espresso within the time range of 25 seconds to 30 seconds.

Barista Tip! Make small changes to your coffee grinder setting each time. It is easier to achieve the sweet spot for your coffee beans with this method. 

FAQ On Watery Espresso

Why Is My Espresso Shot Thin?

The main reason your espresso shot is thin is due to the coffee grounds are too coarse. Using a coffee that is too coarse will allow water to flow past easily without resistance. This results in an espresso that has a higher water-to-coffee ratio that looks thin as it lacks coffee flavor compounds and oils.

How Do You Fix A Watery Espresso Puck?

To fix a watery espresso puck, you should try using a coarser grind size and/or a lighter tamp. This is because finer coffee grounds tend to retain more water which eventually leads to the watery-looking espresso puck. Furthermore, the resulting espresso will taste sour and bitter.

What Causes Soupy Espresso Puck?

Having your grind too fine is the main cause of soupy espresso puck. This is because fine coffee grounds have a higher tendency of restricting the flow of water. Subsequently, the high water retention at the espresso puck causes it to look soupy and murky. The espresso liquid that manages to make it through will most likely have an undesirable sour taste.

How Can I Make My Espresso Thicker?

You can make your espresso thicker by using a finer grind size. With finer coffee grounds, less water will be able to pass through the bed of coffee during espresso brewing. However, be cautious as using coffee grounds with are too fine will restrict too much water flow resulting in no espresso.

Closing Notes

That concludes the case of watery espresso. If you are a home barista or a beginner barista, I am sure one of these steps will help you solve your watery espresso problem.

After all, no one likes watery coffee. 

I’d highly recommend you tweak one parameter at a time. With this method, you can keep track of your changes and how it affects your espresso’s consistency.

Nothing is worse than having poorly extracted espresso in the morning. Not only the coffee grounds will be wasted, but bad coffee will also ruin your day. 

If you find this piece of article informational, please do share it with your fellow friends. baristas and home brewers! 

Happy brewing!