What Causes My Coffee Machine to Produce Weak Espresso Shots?

There’s nothing quite like a strong, flavorful shot of espresso to kickstart your day. But when your coffee machine starts to produce weaker coffee or weak espresso shots, it can be frustrating and disappointing. Weak espresso is watery, lacking in flavor, and just not satisfying. If you’ve been wondering why your espresso isn’t turning out like it should, you’re not alone.

In this blog, we’ll go over some of the common reasons behind weak espresso shots and give you some solutions to help you get back to enjoying that perfect, rich espresso. Whether it’s an issue with your grind size, water temperature, or something else, we’ll guide you through the troubleshooting process so you can fix the problem and get the best results from your coffee machine.

1. Wrong Coffee Grind Size

One of the most common reasons for weak espresso shots is using the wrong coffee grind size. 

Espresso makers require a fine, consistent grind to produce a strong, rich shot. If the grind size is too coarse, the water flows through too quickly, resulting in a weak cup of espresso. This means that not enough of the coffee’s flavors and oils are being drawn out, leading to a watery espresso.

The Problem

Your grind might be too coarse. This can happen if you’re using a grinder that isn’t set correctly for espresso or if you’re using pre-ground coffee that’s meant for drip coffee or other brewing methods. Another issue is inconsistent grind size, which can be caused by dull grinder blades. 

How to Fix It

To solve this problem, start by adjusting your grinders to a finer setting. If you’re using a burr grinder, make sure it’s set specifically for espresso. It’s also important to regularly check and maintain your grinder. If the blades are dull, consider replacing or sharpening them to guarantee a consistent grind. If you’re using pre-ground coffee, switching to freshly ground beans can make a big difference in the strength and flavor of your espresso shots.

2. Your Coffee Dose is Too Small

Another factor that can lead to weak espresso shots is not using enough coffee. For a strong, flavorful shot, the right amount of coffee needs to be packed into the portafilter. If you don’t use enough coffee, the water flows through too quickly, resulting in under-extraction and a weak, watery shot. Using the right amount of coffee helps make sure that the water takes the correct amount of time to extract all the rich flavors and oils from the coffee grounds.

The Problem

Sometimes you’re simply not using enough coffee. This can happen if you’re eyeballing the amount instead of measuring it, or if your coffee scoop or scale isn’t accurate. If you use different amounts of coffee each time you make a shot, the results will vary, and you may end up with weak espresso more often than not.

How to Fix It

Make sure you accurately measure your coffee dose. A good starting point is to use about 18 to 20 grams of coffee for a double shot of espresso, but this can vary depending on your machine and your taste. Using a digital scale to weigh your coffee can help. Develop a consistent dosing routine, like leveling off the coffee in the portafilter before tamping.

3. Your Machine Isn’t Heating the Water Properly

Water temperature plays a big role in the espresso extraction process. For the best results, the water should be heated to between 195°F and 205°F (90°C to 96°C). If the water is too cool, it won’t extract enough of the coffee’s flavors, leading to a weak shot. On the other hand, if the water is too hot, it can over-extract the coffee, resulting in a bitter taste. 

The Problem

The water temperature in your machine might be too low or inconsistent. This can happen if the heating element in your coffee machine isn’t working or if the machine isn’t calibrated. Over time, the heating element can wear out, leading to temperature fluctuations that affect your espresso. 

How to Fix It

Start by checking your machine’s settings. Many espresso machines allow you to adjust the temperature, so check to make sure it’s set within the right range. If you notice that the temperature is consistently too low, it may be time to have your machine serviced or to upgrade to a new machine with better temperature control. The flow rate of the water through the coffee grounds can also impact the strength of your espresso. A stable pump in your espresso machine helps maintain the right flow rate. 

4. Inconsistent Tamping Pressure

Tamping is pressing the coffee grounds evenly into the portafilter to create a uniform surface. This step is important because it affects how evenly your water flows through the coffee during extraction. If the tamping pressure is too light, water can flow through too quickly, leading to under-extraction and a weak shot. If the pressure is uneven, the water will find paths of least resistance, creating channels in the coffee puck, which also results in uneven extraction and a weak, watery espresso.

The Problem

The problem is tamping too lightly or unevenly. This can happen if you’re not applying consistent pressure or if you’re new to making espresso and haven’t developed the right technique yet. Inconsistent tamping can also happen if you’re using a tamper that doesn’t fit the portafilter properly or if you’re rushing through the process without paying attention to how evenly the coffee is packed. It’s important to make sure the coffee is evenly distributed in the portafilter’s basket.

How to Fix It

Start by using a tamper that fits your portafilter snugly. This ensures that the coffee grounds are pressed evenly across the entire surface. Apply firm, even pressure when tamping. Practicing your tamping technique will help you develop the muscle memory you need to achieve consistent espresso. Another option is to use a calibrated tamper, which is designed to apply a consistent amount of pressure every time, taking the guesswork out of tamping. This is a great option if you’ve just started making espresso.

5. Your Coffee Equipment Needs Cleaned or Repaired

Regular maintenance helps prevent coffee oils, limescale, and other debris from building up and interfering with the brewing process. When your machine isn’t properly maintained, it can lead to weak espresso due to poor water flow, clogged filters, and worn out parts.

The Problem

One common problem is clogged filters or group heads. Over time, coffee grounds and oils can build up in these areas, limiting water flow and leading to under-extraction. Another potential issue is worn-out parts like gaskets or seals, which can cause leaks or reduce pressure, resulting in weak coffee. Limescale buildup in the boiler or heating element can affect water temperature and pressure too.

How to Fix It

To keep your coffee machine in top condition, it’s important not to skip regular cleaning and maintenance. Start by cleaning the group head and portafilter after every use to remove any coffee residue. Backflush your machine with a cleaning solution every once in a while to clear out any buildup. Descale your machine often, especially if you live in an area with hard water, to prevent limescale buildup. Check your machine for signs of wear, like cracks in the gaskets or seals, and replace these parts if they’re broken.

6. Using Poor-Quality Beans or the Wrong Roast Level

You need fresh, high-quality coffee beans to make strong, flavorful espresso. Beans that are old, stale, or low quality lack the oils and flavors you need to make a rich shot. Espresso requires beans with a robust flavor profile because the short extraction time highlights the intensity of the coffee. Using poor-quality beans leads to poor espresso shots, no matter how well you’ve prepared and brewed it.

The Problem

Coffee beans start to lose their freshness and flavor as soon as they are roasted, and this loss continues over time, especially if you don’t store the beans the right way. Another issue is using beans that aren’t suited for espresso, like the ones that are meant for drip coffee. These beans might not have the intensity you need for a good espresso shot, leading to a weaker taste.

How to Fix It

To make sure your espresso is strong and full of flavor, always use fresh, high-quality beans. Look for beans that have been roasted recently, ideally within the past few weeks, and check the roast date on the packaging. Store your beans in an airtight container in a cool, dark place so they stay fresh. Avoid buying beans in bulk unless you can use them quickly; they go stale over time. Choose beans labeled for espresso since these are usually roasted and blended to produce the rich, bold flavors that espresso needs. 

Contact Ohio Specialty Coffee Equipment Today

We Turn Watery Brews Into Strong Espresso Shots 

If you’re still having trouble with your espresso machine, our coffee equipment repair experts are here to help. We offer professional repairs to keep your machine in top condition. Don’t let weak espresso ruin your coffee experience—contact us today to schedule a service or get advice from our team of experts. 

Call us today to learn more about how we can help you brew the perfect espresso every time.