Ensuring Accurate Spice Measurements: Addressing a Key Source of Error in FoodSens Gen 4 Testing

How a simple timing issue can affect your Scoville Heat Unit results and how we’ve fixed it.

We are committed to providing not only cutting-edge analytical tools but also the support and knowledge to ensure you get the most accurate and reliable results possible. Sometimes, that means listening closely to our users, learning from their experiences, and making improvements.

We want to extend a sincere thank you to one of our astute clients, whose meticulous work recently highlighted a potential source of irreproducibility in Scoville Heat Unit (SHU) measurements. Their findings allowed us to investigate, understand the root cause, and immediately implement a crucial update to our guidelines.

This blog post will break down the issue, the science behind it, and the simple step you can take to ensure your readings are always consistent.

The Issue: A Delay in Starting the Test

The FoodSens Generation 4 is designed to be simple: insert the sensor, apply a drop of your sample, and press “Start” on the companion app. However, we discovered that if there is a significant delay between applying the sample and pressing “Start,” the reported Scoville Heat Units can be artificially high and inconsistent.

In other words, if the sample is left sitting on the sensor for even 30 seconds before the measurement begins, the final result may not be reliable.

The Root Cause: The "Sticky" Nature of Capsaicin

Why does this happen? It all comes down to the fundamental chemistry of the molecule we’re measuring: capsaicin.

Capsaicin is an organic compound that is highly lipophilic (fat-loving) and has a strong tendency to adsorb onto surfaces. When a chili sample is placed on the sensor’s sensing zone, the capsaicin molecules immediately begin to move out of the liquid sample and bind to the sensor’s surface.

The longer the sample sits idle, the more time capsaicin has to “enrich” or accumulate on the sensor. When you finally press “Start,” the device is measuring this pre-concentrated layer of capsaicin rather than the true concentration present in the original liquid sample. This leads to an elevated and inaccurate signal.

The Data: Quantifying the Impact

Our client’s testing provided clear data demonstrating this effect. They measured the same sample multiple times, varying only the delay before starting the test.

At a 10-second delay: The sample measured approximately 6,000 SHU.

At a 30-second delay: The measurement jumped to approximately 9,000 SHU—a 40% increase.

At longer delays (60-120 seconds): The readings continued to climb before eventually plateauing as the sensor surface became saturated.

This data classic absorption curve is a textbook example of molecule adsorption over time, confirming the root cause.

The Solution: An Immediate Update to Best Practices

The fix for this potential error is very simple: Speed.

To ensure the most accurate measurement of the capsaicin in your sample—and not the capsaicin that has stuck to the sensor—you must initiate the reading immediately.

Our updated official best practice is:

Apply the sample and press “Start” on the app within 5 seconds.

We have already updated our electronic Instructions for Use (IFU) to make this critical timing explicit. Updated physical manuals will be included in all future product shipments.

Best Practices for Perfect FoodSens Gen 4 Results

To recap, here is the correct workflow for measuring Scoville Heat Units:

Insert the capsaicin sensor into your FoodSens Gen 4 device.

Prepare your liquid sample.

Place a drop of the sample onto the sensor.

Immediately pick up your device and press “Start” in the app—aim for within 5 seconds.

Wait for the measurement to complete.

By following this protocol, you eliminate this variable and ensure your results are reproducible and truly representative of your product.

Looking Ahead: A Commitment to Continuous Improvement

This feedback has also sparked internal discussion about potential hardware and software enhancements, such as an “auto-start” feature triggered by sample application. While we must carefully consider any changes to avoid unintended consequences, it is a testament to our commitment to innovation and user-driven design.

Have Questions?

If you are a FoodSens Generation 4 user and have any questions about this update, your device, or your results, our support team is always here to help.