The Cutting Edge: Inside your coffee grinder
Words by Kyle Ramage, Black&White Coffee Roasters
The burrs are arguably the most important part of your coffee grinder and Kyle Ramage, US Barista Champion 2017 and co-owner of Black&White Coffee in Raleigh, North Carolina, has had over 10 years experience on the technical side of these integral pieces of coffee equipment.
I’m going to try and give you a basic breakdown of what’s going on inside a coffee grinder, specifically the ones you see at your local cafe every day.
Firstly, let me just give you the lay of the land. I worked with Mahlkönig which is exclusively a flat burr manufacturer. There’s only a few major coffee burr manufacturers in the world. MKT (Mahlkonig Technologies) which is kind of a hodgepodge of Ditting and Mahlkönig grinder products which are in a ton of super automatic machines as well as of course the grinders that are branded by those two companies. Then there are two major companies in Italy that make burrs for most of the other coffee equipment brands. These names are only known to people deep within the industry, but they make burrs for the Nuova Simonelli Group and Anfim. Mazzer makes most of their own discs. Innovation in grinders takes place at this level of production, as the focus has been on disc technology over the last 10 years and how the discs in the grinder impact flavour.
There are two main styles of burrs. Conical and Flat. Functionally conical and flat burrs are designed to do the same thing, essentially they turn big bits into smaller bits. All I know is what I’ve experienced and in my experience, conical discs tend to make a grind profile that is a bit different and in my opinion, not as good as flat discs. If you look at it as a mountain of grounds, it would be a quite broad mountain of particle distribution sizes. Meaning that there is quite a big difference between the smallest and biggest pieces even within the median grind profile. This does some really interesting things for extraction. It makes extraction a little bit uneven, but it makes it flow really consistently, which is super interesting. They are pretty forgiving on coffees. So back in the day when I really got into coffee in 2007/2008, conical burr grinders were everything, right? If you didn’t have a conical burr espresso grinder you were not about the coffee life! What I learned is that they do they work really well for a darker roasted coffee, that you don’t really want to extract with super high TDS (Total Dissolved Solids), but you really want those thick and viscous ristretto, old school, full crema shots. That’s where they excel and they can make really great espresso for milk beverages.
Flat disc grinders on the other hand, tend to make coffee that is a bit more transparent, meaning the coffee is a little bit more vibrant, has a little bit more clarity to its extraction style. This is really seen in the market in two main manufacturers. Both of them kind of stumbled upon this flat burr revolution, in my opinion, by accident. Basically as the trend in coffee moved towards clarity and vibrancy, flat burr grinders became more in vogue. So then there are a further two styles of flat burrs; The ones made for the Nuova Simonelli (NS) Group grinders that have done a lot of work with coatings (we will focus on that a bit later when we talk about materials) and then there’s Mahlkönig. In my experience with the discs in the NS grinders and the Anfim grinders they make coffee that’s an interesting hybrid between the two disc styles. They still have quite a wide particle distribution, which makes the coffee flow in a really pretty way, but it’s significantly more uniform than a conical burr grinder, so they produce shots with a very consistent flow rate.
A difference between a Mazzer Robur or any big conical grinder and then an EK43 for espresso, even if you’re just like looking anecdotal evidence, the more consistent the grind profile or the more consistent all the particles are inside, the more consistent extraction you’re going to get. So your shots will have a little bit more vibrancy and there’ll be more transparency of the coffee flavours. Which can be a good thing for coffee competitions but it may not be the desired effect for the café space. Uniform does not necessarily equal better, it just equals more consistent. So that also has knock on affects on usability in the café in my opinion.
Mahlkönig grinders tend to be more finicky when it comes to heat management and grind settings, because of the fact that they are physically more uniform in particle distribution. So this means it takes a little bit more care and a lot more attention to detail to manage a grinder that has more consistent particle size distribution. Basically, when you’re moving the mechanism to change the grind up and down you’re actually moving it pretty far from the original particle size, probably a lot further than you think, so it could be a little bit more finicky to keep in check. I like the EK43 (originally designed for commercial bulk grinding), but they’re also super finicky for that same reason; the more uniform the grind, the more difficult they’re going be to use. Because you have to get the setting exactly right for each coffee. Whereas with the Mazzer Robur, there’s a lot more give and a lot more room to play with to get a good result. It’s like cars. If you look at the street cars that we drive everyday and are very used to driving, they’re really soft and squishy and really easy to use, because they’re designed to be driven everyday. But a race car or even a car that isn’t designed for comfort, are much more difficult to drive, much more harsh, crazy intense and a lot more feedback to the driver. So the same is true of coffee grinders, the more you get to the ragged edge of what’s possible, the more difficult they are to control and use.
Grinders, especially commercial ones, have large electric motors. That’s actually how I affectionately referred to myself when I was selling grinders, an electric motor salesman. The EK43 is quite well known for having a massive one, because it really wasn’t designed for café service, it was designed more for a small commercial grinding solution. The burrs really are the star of the show but if you attach great burrs to a bad motor you’re going to have issues. The width of the burrs will impact the speed too, as the more surface area you have, the more coffee can go through at one time.
Then we get to burr material. Does it make a difference? In my experience, absolutely! There is a lot of research being done and that will be released soon, so I don’t want to give away information that isn’t mine, but yes absolutely burr material makes a big difference. Maybe not necessarily in particle uniformity but in my experience in flavour, which is all I honestly care about. Whatever the laser particle analysing machines tell me is somewhat useful, but what matters is what’s in the cup at the end of the day, right? I did a lot of data collection which was much more qualitative, and in terms of flavour, I’ve been a big advocate of cast steel discs from the very beginning. I am not an advocate of coatings at all. Every coated disc (nitride for example) that I’ve used in my opinion it tasted worse than their uncoated counterparts. And we got into this quite a lot with Anfim. My sample set was only like 30 or 40 shots, but the shots yielded about half a percent lower extraction than when we used the non-coated discs. The other thing to consider is that coated disks are like five times the price so yeah that answers that question for me.
The way I think about material for burrs is the same way I think about choosing a chef’s knife. You know when you go to the shops and they have those stainless steel knives and they’re just really smooth and they’re reasonably priced and then you take them home and everything in the world sticks to them, especially cheese when you’re trying to chop it or anything really, just sticks to side of the blade. And then if you think about the high end knives, especially from Japan, you will see those surfaces are a little more rough, and not quite as mirror finished. The more mirror finish a metal has and the smoother it is, the more chances you have for things to stick to it. In my experience with burrs, the rougher the non-cutting edge of a disc, the breaker parts of a disk are, the more easily the coffee is going to flow through and not get stuck in the shoot, which is going to give you a lower heat retention in the grinder and going to give you a little bit easier throughput for the machine which tends to help with a little bit higher extraction.
I still keep up with the with the Mahlkönig crew, we do a lot of testing for them here in our cafés. We have three cafés here in North Carolina and interestingly enough we have just pulled two of our Peaks from our flagship store and we opened them up to have a look at how they were coping. One of the machines had 100,000 shots ground and the other one had 140,000 shots of espresso on one set of Peak cast steel discs. And they are still in perfect condition. We are very impressed with how long they’ve lasted and the quality they produce.
In terms of what is new on the market, I’ve had the chance to test both the Mahlkonig E80 and E65 Grind by Weight. The E80 is like the Peak, but better, it has a more powerful motor, better internal fans, significantly better user interface. I was really happy with how that’s turned out. They have a 3 second grind time for an 18 to 20g espresso, it’s pretty rad! We chose cast steel discs for the grinder, which is a upgrade you have to pay more for, but the flavour has just been insane. Then the other machine that is in our café that has been freaking rock solid has been the E65. This is the machine that I was working on back when I worked there about 4 and a half years ago, it’s a grind by weight solution. You can clip the portafilter in, it weighs the portafilter, tares the scale and and grinds the coffee straight into the basket to within a 10th of a gram and is just super rock solid consistent. I’ve also loved the new interface. From what I understand they worked with an app developer on this particular one and it’s just been amazing how they were able to utilize very logical things to make it a very easy to use menu, very easy to adjust the timer for the grind, very easy to use everything, which has been fantastic. And also maybe not super relevant but some super cool light stuff. I work in live audio production too, and lights and colour help that process a lot, so they’ve brought this sort of haptic style into the grinder. When it’s grinding it’s green and when it’s done it’s white, which makes it a multi-level communication device which is easy to understand, I’m impressed they’ve thought that far ahead. I think this is going to be the future of how we measure all our equipment, how easy all of our espresso machines and all of our grinders are to use and work with, because now we all have smart phones in our pockets that are super intuitive and logical to use.
We love hearing about new coffee brewers and Gareth Newton from Koffie Seriously got in touch recently with a new take on an old style of brewing.
It is based on the cupping principle, there is no filter. We watched James Hoffman's video on the ultimate french press method and it got me thinking about immersion brewing.
I also had an awesome cupping experience and these two important lessons in coffee inspired us. Why aren't we drinking coffee the way we taste test it? I had experimented with Jezve coffee and appreciated more age old forms of coffee brewing. But we wanted an easy way to brew that meant you could put your ground coffee and water into a singular vessel, allow it to brew, and then pour a clear and flavorful cup of coffee. And so the drawing and prototyping began. And after much trial and error we came up with this design. While it is simple, it works!
The concept is that after you break the crust the brew naturally settles and after 4 minutes (the entire brew time is 6 to 8 minutes depending on recipe) the brew has reached sufficient clarity to pour. With the "James Hoffmans french press method" the French press sieve serves to remove any sediment near the end of the pour. The shape of our brewer has been refined so that there is a weir effect. It is slow coffee, and it is easy and forgiving when it comes to grind size but still lots of fun to experiment with. We prefer a 1:13 ratio but a 1:17 may be preferred by those who want a cup with more flavour clarity over strength.
It is getting HOT.
One of Mel's favourite Red Espresso® products is the Spiced Chai Latte powder, but she still needs the caffeine kick as the heat makes her feel a little sluggish in the afternoons (we've all been there right?!). So we wanted to experiment with the Dirty chai, throwing an espresso shot into the mix. We are always interested in the way a method has an impact on flavour so we decided to test out two different styles of iced chai latte, blended and straight up.
We discovered that with the blending option, you need to add slightly more spiced chai powder to balance out the dilution from the crushed ice. Also the texture is obviously very different, so if you want something creamy and viscous, go straight up and if you want something light and easy going, go blended.
3 Cupping Spoons (ie 6 teaspoons) Red Espresso Spiced Chai Instant Latte Powder
1 x espresso shot, a lighter roasted, fruity coffee pairs well in our experience
125ml milk (dairy or alternative, dealers choice)
1 cup ice
2 Cupping Spoons (ie 4 teaspoons) Red Espresso Spiced Chai Instant Latte Powder
1 x espresso shot, same as above
1 cup ice
Although Indonesia is the fourth largest producer of coffee in the world, their coffees are not as widely known or as popular in South Africa as one would expect. Last week, we had the chance to taste 12 Indonesian coffees at a special cupping session organised by the ITPC and hosted by Origin Coffee Roasting in Cape Town. And, because coffee is always about community, we were very lucky to meet two fantastic coffee professionals from Indonesia, Muhammad Aga and Resianri Triane, who had travelled from their home country to cup, share and discuss all things Indonesian!
It was wonderful to be around the cupping table again!
All the sessions were fully booked with many of the Cape’s coffee roasters, barista trainers and coffee traders turning out to taste a little bit of Indonesia. The same fun was had in Johannesburg the week before at Father Coffee.
You can read all about the coffees here, but the ones that seemed to impress the palates consistently across all the sessions were the Sakupura Tengger Natural, the Giri Senang Anerobic from West Java, and Enrekekang Toduri yellow honey.
We tasted some crazy flavours like black tea, woody, herbal notes and quite savoury with mostly a lot of body, gentle acidity and a long finish.
Aga, ably assisted by Hayley Arendse, also pulled espresso shots on the Victoria Arduino Black Eagle and San Remo F18, which were delicious as straight espresso and with varying amounts of milk. It was a great day shared with new coffee friends and old ones that we have't been able to see during Covid, tasting some new coffees and learning more about Indonesia and its coffee people.
A huge thanks must go to Anggun Paramita and Ammar from the ITPC, to Joel Singer and the Origin Team, and Father Coffee Team for hosting coffee professionals from around the country, to Electrical Industries, Morrico Imports and Exports and Equipment Cafe for the hardware across the two venues, and of course to Aga and Triane for sharing their knowledge and expertise on their home countries coffee and its people.
For many years on the world stage the Geisha/Gesha varietal has reigned supreme, but this year there were three competitors in the Top 6 who used this little known and ancient coffee varietal called caffea eugenioides.
The farm responsible for cultivating this strange varietal in modern times is Inmaculada Coffee Farms. It has just become one of the most famous coffees on the planet, because World Barista Champion Diego Campos used it to take home gold at the 2021 competition!
The tiny cherries of the eugenioides tree. Pic from Inmaculada Coffee Farms
Below is the story of the eugenioides varietal that is grown at Inmaculada Coffee Farms, specifically Las Nubes:
Just one cup of this coffee was enough to inspire a journey to South America to discover this species for ourselves. Legends and speculation buzz about this coffee. For starters, this is not even the same species as most of the coffee encountered on the market today. Coffea Eugenioides is considered to be one of the parents of modern Arabica coffee. Eugenioides is a very difficult coffee to grow, yielding only 150 grams per tree of unmilled coffee. It contains about half the caffeine of Arabica coffee, which causes the coffee to have almost no perceived bitterness. The defining characteristic of this coffee is its wild, almost unbelievable sweetness. It has a compelling lack of citric acidity that we are so used to in a coffee, presenting a whole new perspective on what coffee can be. Interestingly specialty coffee has honed in on just one species, Coffea Arabica, as the species that has become synonymous with specialty coffee. Over 100 species of coffee have been described, and Eugenioides is hailed as a progenitor of modern-day Arabica.
An abandoned coffee specie that challenge what we know as coffee today, and unlike anything we've ever tasted. Coffee Eugenioides is one of Arabica's unique and tasty parents. This natural processed Eugenioides was rescued and cultivated by Finca Inmaculada in Pichinde Colombia situated at 1900-2000 MASL on the easternmost part of the Northern Andes. Eugenioides got its own unique brand of flavors. This is truly a rare coffee and worth the adventure. Indigenous to the highlands of East Africa, including the Democratic Republic of Congo, Rwanda, Uganda, Kenya and western Tanzania. It has a really low caffeine content, so there isn't bitter cup of this coffee. It's so sweet and easy to drink and has a completely amazing flavor— that sweetness combined with knowing you're tasting something unique makes it better.
The Eugenioides variety is a medium tree with small leafs and beans.
Flavors of Cereal Milk, Papaya, Bubble Gum, Cake Batter, Sticky Rice, & Cap'n Crunch Crunchbenies invade your palate as you know you are tasting a miracle in the making.
Strawberry Yogurt, Confectioners Sugar, Toasted Marshmallow, Guava, Lemon Drop
If you'd like to do a deep dive into obscure coffee varietals (perhaps start a list of what you taste along the way!) then this comprehensive list from SCA provides a solid start point.
Recipe developed by Vernon and Simóne, who are Vegan Lifestyle Bloggers from The Leaf Eaters in collaboration with red espresso®, everyone had so much fun making this tasty drink using red espresso® and almond milk.
Matcha has been used for centuries in Japan as a superfood for its powerful antioxidants and amino acids that help boost immunity, energy and concentration.
The matcha latte mix from red espresso® is the perfect blend of exceptional grade Japanese matcha with just a hint of organic coconut blossom sugar for sweetness.
We used our matcha superfood mix to make a delicious strawberry café-style ice drink using almond milk infused with the amazing green matcha, and topped off with some decadent foam.
You can use store bought vegan strawberry milk or use our creative method below of creating your own. This is the type of ice drink you’ll love as much as the kids do. We’ll have to admit, it totally brought out the kid in us.
Today is International Coffee Day and all over the country coffee lovers are celebrating their favourite beverage and brew methods! So it is very apt, that on today, of all days, we get to welcome a brand-new piece of coffee brewing technology to the world, from none other than one of the global leaders in coffee... Nespresso!
The Godfather of capsule coffee, Nespresso has continued to make great coffee accessible to people in a convenient, time efficient and simple way. So without further ado....(drum roll please!).... We bring you, the Nespresso Vertuo Next!
We're not very good at keeping secrets here at the Coffee Mag HQ, because, well, it's just too damn exciting for us not to want to share the latest and greatest new coffee innovations with all of you! But this time, we were very restrained, and we spent a good few hours in the Coffee Mag test kitchen un-boxing, experimenting and marvelling at everything that is the Nespresso Vertuo Next.
Firstly, this model is designed beautifully. It is typically Nespresso in its minimalist features - literally only one button and one lever on the entire unit. It looks almost predatory on the kitchen counter - we love it!
Secondly, after filling the water reservoir and doing a simple rinse procedure, you’re ready to brew.
And boy, did we get spoiled!
Not only did we receive 3 packs of various sized capsules. Unlike previous models of Nespresso capsules, these Vertuo ones come in various sizes, which the machine automatically detects and knows how much water to extract your beverage with.
3 different sizes, for 3 different sized beverages!
Then we received a beautiful selection of samples (so pretty!)
So many choices!
Finally, we got an awesome recipe pack with which to create a brand-new beverage: The White Chocolate & Coconut Fortado!
White Chocolate & Coconut Fortado anyone?
So what did we do? We made them all, of course!
Getting ready to extract our first ever centrifugally brewed coffee!
The Vertuo system introduces Centrifusion™ technology and a new range of coffee capsule sizes that together allow for different coffee styles. At the touch of a button, the intelligent system reads and recognises the unique barcode on each capsule, adjusting the flow and volume of water, temperature, infusion time and capsule rotation to extract a high quality dark, full-bodied coffee, finished with a silky and generous crema.
Nespresso South Africa currently has 3 models in the Vertuo Next range, the Nespresso Vertuo Next, the Vertuo Next Premium and the Vertuo Next Deluxe in sleek and modern colours. All of the machines have the simple one touch button and feature the Centrifusion™ technology.
“By introducing Vertuo in South Africa, we are expanding at home coffee options for South African coffee lovers and delivering a range of large coffees without compromising the taste or extraordinary quality expected from each cup of Nespresso. Coffee lovers will be able to discover new sizes, whether that is a 230ml Signature coffee mug of their favourite coffee or the Carafe (535ml) for an even bigger Nespresso taste sharing experience.” says Francisco Nogueira, Business Executive Officer for Nespresso Middle East & Africa.
The Colombia, from the Master Origins series.
Then we made this.....
and we got this....
The White Chocolate & Coconut Fortado!