Behind every good coffee is a good grind.
Grind matters
Quantify yours.
Coffee Grind Lab
SEATTLE, WA, USA
Coffee Particle Size Analysis
About Us
Coffee Particle-Size Distributions Using Laser Diffraction
A good cup of coffee or shot of espresso requires coffee grounds with the appropriate distribution of particle sizes for the brewing method. Manufacturers of coffee grinders tout the quality of their grinds, but quantifying the performance of a grinder is a technically complex process. Coffee Grind Lab offers cutting-edge particle-size analysis to coffee enthusiasts and businesses.
Based in Seattle, WA, USA, Coffee Grind Lab uses a Shimadzu laser diffraction particle-size analyzer with a specialized sample cell to analyze a continuous coffee particle-size distribution between 0.5 and 3000 microns (0.005–3 mm).
Reasons to determine the particle-size distribution of ground coffee:
Determine the shape of your particle-size distribution
The shape of a particle-size distribution is primarily affected by the type of grinder used (e.g., roller, flat burr, ghost burr, conical burr, blade) and the the grind setting. The condition of the grinder burrs, and aspects of the coffee beans (type, roast, and age) can also play a significant role.
Diagnose issues with your grind
Over time (and sometimes straight out of the factory) grinders develop issues that affect the quality of the grinds they produce. Excess fine particles, often associated with worn or inefficient burrs, limit flow through espresso pucks and pour-over filters alike. An excess of coarse particles leads to under-extraction and channeling in espresso, and a weak pour over.
Determine optimum grinding RPM
A number of high-performance grinders now offer variable speed motors, allowing for control of both burr gap and RPM (e.g., Lagom P-64, Kafatek Monolith Max, Levercraft Ultra, Weber EG-1, etc.). The addition of RPM as a variable can significantly affect the particle-size distribution of the grounds produced, with higher RPMs generally increasing the fraction of fine particles for a given grinder setting. Comparing particle-size distributions at different RPMs can help identify the best speed for your grinder.
Convert relative grinder scale to absolute particle-size values
Nearly every coffee grinder uses a unit-less scale on its burr adjustment. Using as few as two to three samples, it is possible to establish a robust relationship between grinder scale and actual median particle size (μm or mm).
Compare grinder or burr set performance
You may be interested to know how your grinder or burrs compare to those of a friend, a new model at the shop, or a commercial grinder at your local roaster.
Add objective data to your reviews or product offerings
There is a thriving online coffee community, and appetite for data-forward reviews of coffee equipment and techniques. If you are a content creator working in this space or a purveyor of coffee equipment, particle-size analysis is a great way to add quantitative and objective content to your reviews.
Just a few samples?
No Problem.
Coffee Grind Lab was established to provide commercial quality particle-size analysis to coffee enthusiasts and small businesses.
Determine the particle-size distribution of your coffee grounds.
#1: GRIND AND BAG YOUR BEANS
Grind and Prep: We need 3-5 grams of ground coffee to perform a particle-size analysis, including leaving sufficient sample for a replicate analysis if necessary.
We recommend that you grind your entire typical dose, and send us only a portion. This will give you the most representative sample of what goes into your coffee, and helps control for variables like grounds retention and burr loading that might bias the sample if you just pulsed your grinder to get a few grams out.
We suggest that you grind onto a piece of paper and then use a knife to “cone and quarter” your grounds in order to get a representative sample. One quarter of your typical dose is sufficient for an analysis.
Bags: We find Ziplock-style sandwich or snack bags to be a convenient way of containing grounds during shipment.
#2: COMPLETE PAYMENT AND INCLUDE YOUR SAMPLE INFO IN THE PAYMENT FORM
Payment is simple and secure. Make sure you provide a valid email to which we can send your results. Confirm that the name used for payment matches the return address on the envelope containing your grounds. If there is a mismatch between shipper and payee, please include a comment on the payment form.
Please note that there are 10 optional fields on the payment form where you can add information about your samples (e.g., grinder model and grind setting). This information will be included in the header of your results PDF. If you plan to submit more than 10 samples, please contact us for bulk intake instructions.
#3: MAIL US YOUR GROUNDS
If sending multiple samples for analysis, make sure that each sample is clearly marked with identifying information (e.g., Sample #1, Mahlkonig #15, etc.). This information, along with any information provided in the checkout form, will be included in your results PDF.
Send your samples to the Seattle address provided in your email confirmation.
You are welcome to use any delivery service to send your grounds. For a single sample, grounds + bag + envelope may weigh less than 1 oz (28.3 g), and if so, can be shipped with a single USPS First Class Stamp.
If you have a PayPal account, UPS and USPS postage can be purchased and printed at home here.
Coffee Particle-Size Analysis
Determine the particle-size distribution of your ground coffee using our Shimadzu laser diffraction particle-size analyzer. Following sample analysis and data quality control you’ll receive your results via email. Results include publication-quality particle-size distributions plotted between 0.5-3000 microns (0.005-3 mm), particle-size statistics, and a table of the raw data points that define particle-size distribution of the sample.