“If you could build the perfect manual coffee grinder, what would you do?”
Over the last year we asked this question to thousands of coffee enthusiasts around the world. The detail and depth of answers that we received blew us away. Using a coffee grinder marks the beginning of many people's day and it turns out that in many cases, it wasn’t a pleasant one. One gentleman told us that his wife had trouble gripping the grinder and rotating the tiny knob because she has arthritis. A professional barista complained that the manual grinder he uses at home couldn’t produce a consistent grind because the burr is only supported in one location. The inconsistent grind resulted in his coffee becoming over extracted and bitter.
As we asked more questions a community began to build around the goal of building the best manual coffee grinder. Each answer was different but when we looked at the results in aggregate, patterns started to emerge and the features to focus on became clear.
This is the story of how we approached the problem of building a coffee grinder with the assumption that we knew nothing and emerged with a coffee grinder that incorporates the desires of thousands of coffee enthusiasts in one package.
The Current State of Manual Coffee Grinders
The idea to build a coffee grinder started in our kitchen while we were experimenting with different brewing methods and learning the nuances of brewing coffee. The first thing we learned was that a burr coffee grinder produces a more consistent grind than a blade coffee grinder. A burr grinder crushes the beans into a consistent particle size while a blade grinder randomly chops the beans as the blade whizzes.
We purchased one of the best selling manual coffee grinders on Amazon and ran into a number of problems the first time we used it. The beans would slosh out of the hopper and spill, turning the handle was awkward and setting the coarseness level was a game of chance. We persevered for a couple days but each morning while making our coffee we would talk about how we could improve the design.
Our patience finally broke when we had the coarseness setting at the perfect level for an Aeropress coffee and then our roommate changed the setting to make a french press. Our setting had been lost and there was no going back!
We wondered if anyone else was experiencing the same problems as us so we went to Amazon and began reading reviews.
After reading hundreds of comments, it was clear that we were not the only ones frustrated with these coffee grinders. We built a landing page called CrowdCoffee and started commenting on Amazon comments inviting people to help us build a new coffee grinder. Our idea was that we could use crowdsourcing to determine what features people may want in a new coffee grinder and challenge our assumptions by gathering feedback from fellow coffee enthusiasts.
Team Handground is Born
We made it a goal to leave comments on Amazon comments each day and one by one our team began to grow. We also started an Instagram account and began to share pictures of our progress every day. When people joined we asked them about their relationship with coffee and why they wanted to be a part of the project. The underlying theme across the answers was a passion for coffee and the desire to create something new.
Working with Team Handground, we used a “prototype, feedback, iterate, repeat” cycle at each step of the design process. We conducted surveys and tested our assumptions to identify key features and rule out useless ones. These surveys were designed to guide our team through the decision-making process, introducing as little bias as possible and developing a coherent story about why we were considering each feature.
We constantly worked to improve our surveying techniques in order to receive the most accurate feedback possible. The questions we asked were aimed at past experiences instead of asking people to predict what they think they would do in the future. We even went as far as conducting "visualization" exercises to put members in the mindset of making their morning coffee, thinking about where their hands are, and what markings would be easier to use or measure with. While it is not as good as having a prototype in your hands, 58% of respondents reported that the visualization was helpful.
The result of this effort is a feedback loop that has the power to harness thousands of opinions and distill them into a coherent, decisive step forward.
What Features Would Make The Best Coffee Grinder?
We had a lot of ideas on how to create the best coffee grinder, but we wanted to challenge our assumptions by asking Team Handground for feedback on each feature.
Each section below represents a feature we considered incorporating into Handground, including the resulting score from votes by Team Handground and the final result on whether or not that feature made it into the production version.
Consistent Particle Size
Theory: Create a consistent grind by stabilizing the axle that the inner burr is mounted on.
Result: Yes - Handground has a triple mounted axle that prevents the inner burr from wobbling.
Most manual burr grinders on the market offer little consistency from grind-to-grind. This is particularly true when users want coarse grinds for French Press, Chemex, or Cold Brew. To make a good cup of coffee, you need a consistent particle size so there is an even extraction of coffee when hot water passes through the coffee grounds.
The root of this consistency problem has notoriously been an unstable axle that allows the inner burr, which is attached to one end of the axle, to wiggle while grinding. This occurs because most axles are only mounted in one location. The back-and-forth movement of the burr allows coffee grounds of different sizes to fall between the burrs and into the catcher.
To address this problem Handground uses a stainless steel axle that is mounted in three locations, along with ceramic burrs to produce a consistent grind.
Airtight Hopper to Store Beans
Theory: Since our hopper holds 100g and a typical cup of coffee only uses 25g, an airtight hopper would allow you to store beans in it without risking them going stale.
Score: 2.5 / 5, where 5 is "Very Important" and 1 is "Not Important"
Result: No - Most people have dedicated storage for their coffee beans, so a sealed hopper is not an important feature in a coffee grinder
Feedback from Team Handgound:
Easy Coarseness Adjustment Ring
Theory: Create a twistable ring to make it easy to select from preset coarseness settings
Score: 4.3 / 5
Result: Yes. Handground has a coarseness adjustment ring with 15 settings at 185 micron intervals
Many members of Team Handground want to use their manual burr grinder for more than one type of brewing method. However, most hand-crank coffee grinders make this very difficult because they offer no reliable way to adjust the coarseness setting. The traditional, “screw-and-lug nut” coarseness adjustments of most manual coffee grinders offer no point of reference, so measuring your grind setting is near impossible.
Inspired by the lens of a DSLR camera, we designed a rotating ring in the center of the grinder to easily adjust the grind coarseness. With a simple twist, users can adjust the coarseness, observing the numbers on the ring with respect to an arrow on the hopper to know exactly what grind setting they are using.
Dots vs Numbers to Indicate Coarseness Setting
Theory: We originally launched Handground with dots on the coarseness ring, but members of Team Handground kept suggesting we change to numbers so it is easier to communicate grind settings.
Score: 47.7% Dots / 53.3% Numbers
Result: Numbers
After much debate, numbers won the vote on the basis that it is easier to communicate a number than a dot position when you are sharing what setting you used when preparing your coffee.
Side Mounted Handle
Theory: The top mounted handle on most manual coffee grinders is awkward to use while a side mounted handle affords a more natural motion.
Score: 69% Side / 31% Top
Result: Yes. Handground is the only portable manual coffee grinder to feature a side mounted handle.
Some of our biggest improvements weren’t just mechanical, they were ergonomic. We heard complaints that the current designs of manual burr grinders made grinding coffee slow and difficult.
One of the most obvious factors that make grinding difficult is the awkward motion required to operate most manual coffee grinders because their handles are mounted on top. We suggested mounting the handle on the side and Team Handground overwhelmingly agreed.
The beauty of a side-mounted handle is not only that it makes grinding easier and more comfortable, but also that it speeds up the grinding process by making it easier to grind at a higher speed.
Creating a side-mounted handle was easier said than done. The key to making this work is a well-designed gearbox to transfer energy from the side-rotating handle to the vertical axle, powering the ceramic burr to crush the coffee beans.
Creating our own custom gearbox was a huge challenge, but we were able to get it done with the help of Team Handground. Their introductions led us to the help we needed to design a durable, long-lasting gearbox that could withstand the pressures of crushing even the smallest, most dense, lightly-roasted coffee beans.
2:1 Gear Ratio for Faster Grinding
Theory: The side mounted handle gives us the opportunity to use a 2:1 gear ratio to speed up grinding
Score: 3.9 / 5
Result: No. This idea was good in theory but once we created a prototype we learned that it would be too difficult to turn the handle and grind beans.
Feedback from Team Handground:
In this case, we had to create a physical prototype of our idea before we learned it wouldn’t work. When we began designing the gearbox that would connect our side-mounted handle to the axle, we wanted to increase spin ratio to make grinding faster.
Using extra gears in the gearbox, we wanted to create a positive gear ratio that would spin the burrs faster with every turn of the handle. Team Handground thought it was a great idea too, but only after testing the prototype did we learn it was too difficult to grind beans with an increased spin ratio.
Finish Options: Plastic vs Brushed Metal
Theory: A brushed metal finish is more appealing than a plastic finish but it may be too expensive to diecast the components from aluminum.
Score: 92.2% Brushed Metal / 7.8% Plastic
Result: Handground has three finish options: Black or white plastic, and brushed nickel that is electroplated over the plastic components to achieve the brushed finish while keeping the cost down.
We asked the community to estimate how much they think the grinder should sell for, while also asking them how much they spent on their last piece of coffee equipment. This way we could get an idea of their expectations while also understanding how much they spend in reality.
Full die-cast aluminum parts were considered for the grinder, but after calculating the costs we discovered that this process would cost considerably more than electroplating (almost 2x the part cost for those components). This would have pushed the end retail price out of the range that Team Handground expected to pay for the grinder, while the end price after electroplating fell within the estimate.
It was important for us to incorporate both the expectations of Team Handground and the reality of their actions. We decided to offer the plastic finish as well because its end retail price fell in line with how much the community is actually spending on coffee equipment.
Measurement Marks on The Hopper
Theory: Adding measurement marks to the hopper will make it easier to approximate the amount of beans for your brew method when a scale isn’t available.
Score: 75.6% Yes / 24.4% No
Result: Yes. Handground has 7 staggered measurement marks on the side of the hopper
It is important to control every variable with precision when brewing a cup of coffee. This includes the ratio of coffee to water, which is why a scale can be so important. But when considering the reality that a scale is not always available, measurement marks make sense. They provide the ability to approximate how much coffee is being ground to more easily brew a better cup of coffee.
Grip Over The Hopper
Theory: A grip over the hopper would make it easier to hold and add an aesthetic touch to the overall appearance of the product
Score: 61.2% Without Grip / 38.8% With Grip
Result: No. The consensus was that it would be better to see the beans inside of the hopper than have the grip covering them.
Other considerations for a grip were made but in the end a clear and clean hopper won the overall vote. This also fell in line with the objective to keep the overall cost down. When we asked the community which factors most influence their purchase of coffee equipment, cost was the number one factor.
Handground Design Competition
With a complete list of features from the community for the new grinder, we launched a design competition. We chose to do a competition instead of working with one designer so we could compare between many different aesthetic approaches.
The key to our successful competition was a strict set of design constraints, like the side mounted handle and coarseness adjustment ring, that the designers had to work within. As the submissions came in, we worked with Team Handground to give feedback to each designer to help guide the overall look and feel of each design.
In total there were 184 design submissions and the winning one was from industrial designer Joaquin Herlein of Argentina. The full story about the competition can be found on the 99Designs blog here.
The design featured on the left is what Handground looked like when the design competition ended. The design on the right is the final Handground design that made it to production.
Handground Precision Grinder
Better Grind, More Flavor
Bringing Coffee People Together
While Team Handground started as a way to create the best manual coffee grinder, it has grown into a movement. It’s a community of people who aren’t just passionate about coffee, but passionate about improving the coffee world.
"This is probably a once in a lifetime deal for most people,” -CrowdCoffee Welcome Survey
"I think it will be interesting, I have never directly participated in the design process before on any level.” -Coffee Experiment survey
"It intrigues me to know that I could be part of the next generation of coffee drinkers.” -Coffee Experiment Survey
We created the best manual coffee grinder we could thanks to Team Handground, but this is just the beginning.
Join Team Handground below and let’s create something together.
