Time to Replace Your Coffee Machine? Maybe Not Just Yet!
As coffee aficionados, we all know that perfect espresso is more than just a drink—it’s an experience. But what do you do when that beloved espresso machine starts delivering lackluster shots? Before you jump to conclusions and start browsing for a new machine, there’s one crucial tool you should consider: a refractometer.
A refractometer measures the Total Dissolved Solids (TDS) in your coffee, offering you an inside look at how well your machine is extracting the rich flavors and aromas from your coffee grounds. By understanding your TDS levels, you can make informed decisions about whether your machine really needs to be replaced, or if it just needs a little TLC.
The Story of a 6-Year-Old DeLonghi Magnifica
Take the case of a 6-year-old DeLonghi Magnifica, a reliable fully automatic espresso machine that’s been churning out cups for years. Over one month, 30 samples of coffee were brewed and analyzed for TDS, Brix, and Index of Refraction. Here’s what we found:

The average TDS for these samples was around 1.7%. To put that in perspective, a well-made espresso should have a TDS between 8% and 12%. A TDS of 1.7% indicates that the coffee being produced is much more diluted than it should be—think more along the lines of strong drip coffee, or Americano, rather than the robust, concentrated espresso you expect, let alone something coming close to a ristretto.
Why a Refractometer is Your Secret Weapon
Before you decide that your machine is the culprit, consider this: several factors could be causing that low TDS reading, and a refractometer can help you pinpoint the issue.
Here’s how:
- Grind Size Consistency: If your coffee grounds are too coarse, they won’t extract properly, resulting in a weaker brew. A refractometer can confirm if this is the case.
- Water Temperature Precision: If your machine isn’t hitting the right temperature, it could be under-extracting your coffee, leaving you with a less-than-satisfying cup.
- Brewing Technique Optimization: Are you using the right amount of coffee? The correct water volume? A refractometer helps you adjust these variables for optimal extraction.
By providing concrete data, a refractometer can save you from unnecessary expense and frustration, allowing you to fine-tune your current setup for a better brew.
Why Buy a Refractometer Before Replacing Your Machine?
Here’s why investing in a refractometer might be the best move you make:
- Accurate Diagnosis: Before blaming your machine, a refractometer gives you the tools to identify if the issue lies with the machine or with factors like grind size, water temperature, or brewing method.
- Cost Savings: A refractometer is a fraction of the cost of a new espresso machine. By tweaking your current setup based on accurate TDS readings, you could extend the life of your machine and improve your coffee quality without the hefty price tag.
- Empowered Brewing: With a refractometer, you become the master of your espresso. You can experiment, adjust, and perfect your brewing process, turning your kitchen into a mini coffee lab.
When Should You Really Consider a New Machine?
If after using a refractometer you find that no matter what adjustments you make, your espresso consistently falls below the ideal TDS range, it may indeed be time to consider an upgrade. A new machine can offer better pressure control, more consistent temperatures, and other features that contribute to the perfect shot of espresso.
However, by investing in a refractometer first, you might discover that your current machine still has a lot of life left in it. And when the time does come to buy a new machine, you’ll have the knowledge and tools to get the most out of it right from the start.