Why It Matters: Grinding Your Own Coffee
Introduction
In a recent, yet random deep dive into coffee freshness information, I uncovered an old article from 2012 by Emma Sage, the then Coffee Science Manager of the Specialty Coffee Association of America (SCAA). The title of the article was, “What is the Shelf Life of Roasted Coffee? A Literature Review on Coffee Staling.” While an older piece of text, I found a lot of the information relevant and interesting (I have yet to search for more recent studies or information – hopefully I’ll be able to share fresh information in the future). I was already planning on writing a blog about the effects of grinding your own coffee, and this information seemed to fit well, albeit creating a bit of a wandering path to the desired outcome.
There’s something undeniably convenient about grabbing a bag of pre-ground coffee off the grocery store shelf. It’s quick, easy, and ready to brew. Even Emma Sage offers that, “coffee is what is known in the food science field as a shelf-stable product, which after roasting does not spoil due to enzymatic or microbial processes,” which seemingly validates the idea that coffee can be consumed at any point after roasting. But if you’re willing to dive a little deeper, or if you’re looking to improve the flavor of your morning brew, you’ll find that while coffee is shelf-stable, it is far from flavor or aroma-stable.
It's somewhat difficult to evaluate the flavor of coffee and its relationship to freshness. The Specialty Coffee Association of America (SCAA) water quality handbook states that, “coffee’s flavor potential is constantly changing. As a result, when conducting a chemical or sensory analysis, coffee must be considered a moving target.” We do, however, have compelling research that supports the general claim that coffee tastes better when fresh. We also have comprehensive research on how coffee loses its freshness, from the degassing of carbon dioxide to exposure to oxygen.
There are many ways to improve your home coffee. If you’re looking for the elusive silver bullet to this complex problem, however, grinding your own beans is one of the most important steps you can take (outside of purchasing Canyon Coffee Roasters coffee, of course). The difference in flavor, aroma, and overall freshness is immediate and noticeable.
Grinding your own coffee allows you to unlock more of the bean’s potential, preserve delicate flavor compounds, and customize your grind for your preferred brew method. But just as important as the beans you buy is the grinder you use to prepare them. Not all grinders are created equal, and choosing the right one is a crucial part of improving your daily cup.
Why Pre-Ground Coffee Falls Short
Research has identified several key reasons why coffee loses its freshness, flavor, and aroma. Our reference article by Emma Sage neatly summarizes these reasons when she states that, “overall shelf life of coffee is dependent on the state of the coffee (whole bean vs. grind) and environmental conditions.” Those environmental conditions include, “temperature, moisture, and most importantly, oxygen availability.” Linking the state of the coffee to environmental conditions is the coffee grind, in that when coffee is ground, “the porosity and surface-to-volume ratio increase, which accelerates degassing and staling.” To summarize, temperature, moisture, and oxygen exposure are directly linked to loss of freshness, flavor, and aroma. Grinding coffee accelerates the rates by which these factors take effect.
How much does freshness really matter? Consider oxygen exposure as an example. Ground coffee oxidizes far more quickly than whole bean coffee due to its increased surface area. One study found that reducing oxygen levels in a coffee container to just 0.5% could extend shelf life by as much as 20 times. Another reported that after just one week, tasters preferred coffee stored in a container with 0% oxygen over coffee stored with only 2% oxygen. These findings highlight a clear link between oxygen exposure and flavor degradation—making whole bean storage a key factor in preserving cup quality. Grinding your own coffee allows you to limit oxygen exposure, retaining key compounds that contribute to freshness, aroma, and flavor.
While arguably less scientific in nature, pre-ground coffee also locks you into one grind size, which may not be ideal for your brewing method. Grind size affects how quickly water extracts flavor from the coffee, and using the wrong size can lead to bitter, sour, or weak brews. Grinding your own beans ensures a better match between your grinder and your brewing method.
Choosing the Right Grinder
If I’ve managed to keep your attention this long, and if you’re interested in taking the next step, there are two primary types of grinders: blade grinders and burr grinders.
Blade Grinders
Blade grinders use a spinning blade to chop coffee beans. While inexpensive and easy to find, blade grinders produce inconsistent particle sizes, leading to uneven extraction and unpredictable flavor. Some grounds may be over-extracted (bitter), while others are under-extracted (sour).
Burr Grinders
Burr grinders crush beans between two abrasive surfaces (called burrs), allowing for a more uniform grind size and much better flavor extraction. Burr grinders are the preferred choice for anyone serious about brewing great coffee at home.
Within burr grinders, there are two main styles:
Conical Burr Grinders
Conical burr grinders use a cone-shaped center burr that fits into a hollow, ring-shaped outer burr. These grinders tend to operate more quietly, produce less heat, and are generally more forgiving when it comes to grind adjustment. They’re ideal for most home brewers and tend to be more affordable.
Flat Burr Grinders
Flat burr grinders use two parallel, flat rings to grind beans. They offer incredibly consistent grind sizes and are often preferred by professionals or enthusiasts aiming for precision. Flat burrs can create more heat and are sometimes noisier, but they are excellent for dialing in specific flavors, especially for espresso.
Espresso vs. Brew Grinders
Grinders are often marketed either for espresso or for standard brewing methods (such as pour over, drip, French press, and AeroPress). While some high-end grinders can do both, many are better suited for one or the other.
Espresso grinders require extremely fine and precise grind settings, often with micro-adjustments to get just the right shot time and flavor balance. They usually come with stepless or fine-stepped grind controls for very small changes.
Brew grinders, on the other hand, are designed to handle coarser settings, like medium for drip coffee or coarse for French press. They may not grind fine enough for espresso, or may lack the control needed to fine-tune espresso shots.
If you mostly drink brewed coffee, a conical burr grinder with stepped settings will likely serve you well. If you are pulling espresso, you’ll need a grinder designed specifically for it. If you plan to do both, invest in a high-end multi-purpose grinder—or consider getting two separate grinders to avoid constant recalibration.
Matching Grind Size to Brew Method
Grinding your own coffee allows you to tailor your grind size to your brew method. Here’s a quick guide:
- Coarse – French press, cold brew
- Medium-Coarse – Chemex
- Medium – Drip coffee machines
- Medium-Fine – Pour over (like Hario V60)
- Fine – Espresso
- Extra-Fine – Turkish coffee
Getting the grind right can drastically improve how your coffee tastes. A grinder that offers consistent particle sizes and reliable control over settings will help you hit your target every time.
Buying Whole Bean, Specialty Coffee
Of course, grinding is only part of the equation. The quality of your coffee beans matters too. Most grocery store ground coffee is made from commodity-grade beans and roasted for shelf stability rather than flavor. By buying specialty-grade whole bean coffee, you gain access to a wide range of flavors—from bright citrus to dark chocolate—that are preserved best when ground fresh.
Look for freshly roasted beans from trusted roasters like Canyon Coffee Roasters that indicate roast dates and sourcing information. And don’t be afraid to experiment with different origins, roast levels, and processing methods. Grinding your own beans gives you the control to explore how each of these factors impacts your cup.
Other Ways to Improve Your Brew
This article was written to explore why grinding matters to flavor and freshness. But purchasing a grinder is a serious investment. If you’re not ready to go that direction, I have many other tips for better coffee, including coffee storage, the purchase of quality coffee, cleaning your coffee equipment, and brewing with the correct ratios. To learn more, explore the two articles linked below!
5 Tips to Better Coffee at Home
Unraveling The Secrets of Specialty Coffee
Links to Explore
If you’re convinced and ready to find a great grinder, check out the links below. If you would like specific recommendations, reach out to our team through the Contact Us form on our website. We would love to send you a personalized recommendations based on your preferred brew method and beans. There are many options available and the list is constantly changing. Reach out for the most recent information!
Final Thoughts
Grinding your own coffee is one of the most important upgrades you can make to your brewing routine. It gives you more control, better freshness, and access to a wider world of flavor. But just as important as grinding fresh is grinding well. Choosing the right grinder will help ensure you get the most out of your coffee.
Whether you're just getting started or already making pour overs at home, investing in a quality burr grinder is a decision that pays off in every cup.