Out of the BoxRatio Six
The Ratio Six comes in three colour choices: brushed stainless steel with black accents, matt black, or white with black accents. Our test machine is the white version.
We really encourage companies to embrace 100% environmentally friendly and fully recyclable / compostable packaging, and Ratio does well here overall, though there is too much plastic bags used, when they could have gone compostable bags. We give them an 8 out of 10 for packaging materials.
The shape of the Ratio Six is similar to the typical auto drip coffee maker following the Technivorm / Melitta model of the 1960s, with a visible reservoir on one side, and the carafe on the other. It does strike a more unique shape because of the angle of its carafe side: instead of straight vertical lines, the handle side of the carafe and filter holder are angled. Looking top-down on the machine, it’s not an oval rectangle shape like most brewers, but more shaped like a teardrop – more narrow on the carafe side, and wider at the reservoir side.
The Ratio Six is designed to work either parallel to your kitchen wall, or perpendicular from it, with the carafe side extending towards the end of the counter.
The entire main body of the Ratio Six is painted steel (or plain stainless steel in the non-painted version of this brewer), as is the top cap that goes from the reservoir to the carafe area. Even the reservoir lid is stainless steel. There’s very few gaps too: the base and lower water tower area are a very tight two piece affair that have such tight tolerances, you can barely see the gap where the base meets the water tower. The reservoir is BPA-free plastic on the exterior, with borosilicate glass tubes in the middle of the reservoir for water travelling up inisde to the machine’s dispersion screen over the carafe and filter holder.
There is only one control button on this brewer and it is a soft-touch button (it registers your finger like a smartphone screen does) on the carafe end of the brewer base. There are three indicator lights that flow as white strips during operation: a bloom light on the left, brew light in the middle, and finished brew light on the right. All three will flash if you try starting the machine without the carafe in place.
On the opposite side of the base from the control button is the plug for the brewer, which does have a nice L bend to it to make it less conspicuous.
The machine’s dispersion screen is… huge. It looks about 40-50% the size of the entire flat basket filter area of the filter holder, which means a wide reach for that brewing water. Its concave design is all metal as well.
Dispersion Screen
This screen is big, almost half the diameter of the brew basket filter area.
The carafe is steel inside, with a plastic and metal outer shell and handle. Basically, all the black parts on our test machine carafe are plastic, and all the white parts are painted metal. It is an insulated carafe, but most likely not vacuum insulated, because it’s pretty thick between the inner chamber and outer wall, and weighs almost a kilogram (935g) without lid or filter holder.
The absolute max volume is 1.3 litres of water which is almost overflowing. When you brew 1.3litres (the max batch size), up to 100ml of that water stays with the ground coffee, resulting in about a 1.2l finished brew.
The filter holder is removable and slots very nicely into the main carafe. Like the carafe, all the white parts are metal, and all the black parts are plastic. Its styling and lines match the carafe for a nice silhouette. That silhouette is vertically straight opposite the handles, but angled on the handle side. The filter holder is double walled too, but based on its weight, is not insulated.
On top of the filter holder is what we call the “heat retention collar”. Its purpose is to create a more closed brewing environment and to elevate the filter area’s heat as quickly as possible at the start of the brew, maintaining that brewing heat throughout the brew. It slots nicely onto the filter holder, and has a rubber flexible collar at the top.
When the entire carafe side is assembled – carafe, filter holder, and heat retention collar – it can be a bit finicky to slide into the machine, as the flexible rubber upper collar can get caught up on the machine’s dispersion screen. There’s two ways to overcome this. Either slot the assembled carafe and parts into the machine on an angle, or just take the filter holder and heat retention collar, put it under the dispersion screen and press up to compress the upper rubber collar. With that in place and pushed up, slide the carafe underneath, and place the filter holder into the carafe.
Also included in the box is a plastic drip tray, and the carafe’s screw-on serving and insulation lid. The plastic drip tray’s purpose is to hold the spent filter holder once you remove it from the carafe after the brew is complete. The lid is then attached to the carafe to maintain the coffee’s temperature for hours.
Not a fan of this lid design.
Overall, the Ratio Six is a mix of reassuring quality and… a bit cheap. It is reassuring because the tight tolerance metal construction, the weight of the carafe, the well crafted metal lid for the reservoir, the soft touch button, the glowing lights, and the super quiet operation all seem high quality.
Then you come to the carafe screw on lid which seems it could benefit from better design and better materials. The lid looks like one that could be found on a $50 Target special coffee brewer. The equally cheap plastic drip catcher for the filter holder is the only other component I felt was a bit cheap by comparison to the rest of the machine.
Fortunately though, Ratio spends the money on this brewer where it counts most. Glass tubes for the hot water to travel through the machine in, is nice. The unibody metal skin screams high quality and is solid, unlike the ultra-thin metal skin over plastic that Breville uses for their appliances (as an example). The dispersion screen looks industry leading. The soft touch single button operation is slick. Under the hood, a 1400W heating system gets things moving quickly and smoothly with the pulse-delivery action of the near perfect brewing water temperatures.
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First UseRatio Six
The Ratio Six is a beautiful looking machine; everyone who has been by my test bench when it was in operation remarked on how good the brewer looks. The next thing everyone notices is what I ended up coining “the carafe stack”.
The Carafe Stack, in Place
To brew with the Ratio Six, you have to have the carafe, then stack the filter holder on top of the carafe, then stack the heat retention collar on top of the filter holder. It’s part of the visual look of the brewer, but each part is also integral to how well the brewer performs in terms of in-the-cup results. The problem is, the carafe stack is not very user friendly.
It took me some time to get used to inserting this stack into the coffee brewer. The top rubber collar of the heat retention collar would frequently get jammed up in the protruding dispersion screen, and sometimes the rubber lip would fould over itself, hampering part of the dispersion screen’s water flow the few times I failed to notice it. One could just brew without the heat retention collar in place (and in the full review, I’m going to explore that more); but it serves a purpose and you want to use it.
Ratio’s owner Mark Helweg, told me two ways to insert the carafe stack. One is just to tilt everything at about 15 degree angle on the handle side when inserting it. The other is to separate the carafe from the filter holder and heat retention collar, and to put the latter two items (stacked together) under the dispersion screen and push up to compress the top rubber collar. This gives you about 1.5cm of space to slide the carafe underneath the filter holder, into place on the machine. Then lower the filter holder / heat retention collar stack onto the carafe.
I found the former method (angled insertion) easier to do, and the latter method too annoying to do. Your mileage may vary.
Clearing the Dispersion Screen
Tilting makes the soft rubber collar of the heat collar clear the protruding dispersion screen.
In operation, everything is dead simple with this brewer. Add water to the reservoir, add a flat basket filter paper to the filter holder, give it a gentle rinse under hot water, then add your ground coffee (75-80g max for a 1.3l brew). Insert the carafe stack and press the soft touch button. Everything is extremely quiet with only the sound of gurgling water travelling up the inner glass tubes inside the reservoir.
You can go away and do something else for 10 minutes, reassured this machine will deliver near perfect temperature water pulses out of its extra wide dispersion screen to the bed of coffee during an 8 minute brewing time. After that, come back to an exceptionally well brewed carafe full of coffee.
But, this is when I ran into my second issue with the Ratio Six, and again it’s related to the carafe lid, and the carafe design itself. It’s not very good at pouring coffee.
The lid is chunky and the ‘action’ on pressing down the lid button isn’t very reassuring, nor does it offer any tactile feedback confirming the pour spout is open. When you pour, forget trying to do a slow pour; coffee will dribble out everywhere, including down the side of the carafe. I found the best way to pour with this carafe and lid is to hold it at 90 degrees over your cup, then try to gently press down on the lid lever button. Coffee comes out really quick, but generally all into the cup, and not down the side of the carafe.
I didn’t find this hold hard to do, but my wife did. Your mileage may vary.
The carafe interior design is less than ideal too. The best carafes have a completely even wall design from the interior bottom to where the spout is. The Ratio Six has a pronounced lip near the top, shrinking the upper diameter of the carafe. This is a kind of “step” for the liquid to jump over before making it to the spout and pouring out. Because of this, getting the last bits of coffee out of the carafe is not easy to do, and often results in a mess. This photo demonstrates the lip issue.
Inside the Carafe
Hard to make out, but there's a pronounced lip for coffee to overcome to pour out of this carafe.
Longer Term UseRatio Six
I’ve got about 10kg of coffee through the Ratio Six brewer, and here’s the things I’ve learned so far.
The Bloom Process
One of the key features on the Ratio auto drip brewers is their bloom process. The “bloom phase” means introducing a small volume of brewing water to saturate the bed of coffee, then pausing the water delivery for a calculated time. Once that time is up, the machine continues delivering the rest of the brewing water to complete the brew process.
The Ratio Eight is a lot more complex with things like a pressure sensor to detect the difference between air pressure and water pressure inside the machine. It does this to make a good estimate on how much ground coffee you’ve added to the filter. Based on what it calculates, the Ratio Eight sets a specific volume of water to use in its bloom process, usually 2 times the weight of the coffee it detects in the basket.
The Ratio Six doesn’t have these additional complex mechanisms, and instead has a pre-programmed bloom phase delivering about 150ml to the filter basket, then pausing for around 30 seconds before continuing the brew. This amount and timing is based on doing a full batch brew of 1.3l of coffee, but it’s less than ideal if you’re doing a half batch (700ml) or less. This is one of the tradeoffs Helweg made to get the Ratio Six into the price point he wanted.
Bottom line? The bloom function works great for 800ml or greater on the Ratio Six. If you’re doing 500ml brews, not so good.
All in all, brews a fantastic cup of coffee.
On the Showerhead
A signature element of the Ratio brewers is their wide dispersion, concave shaped water showerhead above the bed of ground coffee. “The Ratio Six has a much wider showerhead than most automated coffee makers and our built in bloom cycle has been designed and tested to have a big impact on the finished coffee.” Helweg told me.
The Ratio Six’ showerhead is the culmination of years of prototype testing and modifications Helweg and his design team have done to their brewers. As he says “it’s now as good as it can possibly get”, and it shows in the overall extraction rate and saturation levels of the bed of coffee.
It definitely is a pride-point of the machine. And in practice, the dispersion screen works very well, with water coming out of all the holes and over the full diameter of the screen.
Water comes out of every hole in the dispersion screen, in timed pulses.
Flat Bottom Filters
One big difference between the Ratio Eight and the Ratio Six is that the latter is designed to use flat bottom paper filters. Ratio is owned by Helweg, who also owns Able Brewing, the makers of the iconic Kone permanent filters for Chemex and V60 brewers, so it seemed a weird choice.
“We had a lot of internal discussion about what our filter would be on the Six.” Helweg said. “Do we lean into our system, what we think is the best filter overall (The Chemex filter paper, or the Kone permanent filter), but no, what’s important is that people brew delightful coffee, have pride in their ownership and such, so we did some consumer research. Based on what we learned, including what we learned from SCA (Specialty Coffee Association) research of filters, we felt flat bottom filters would do the job well.”
Helweg also referenced a test the SCA and Breville did in 2019, putting conical filters against flat filters to test the impact on flavour and overall cup quality. Their results was that flat bottom filters enhance coffee depth and notes like chocolate, nougat, and other rich sweet-savoury flavours, where conical filters were better for citrus and bright flavour presentation.
Adding coffee to the Ratio Six's flat bottom filter paper.
Part of it is that Helweg always saw the Ratio Six as a batch brewer – intended to be used more often at its maximum brewing volume – and in that scenario the Ratio Six worked better overall with flat bottom filter paper. The Ratio Six is also a “closed brewing environment” with the filter area almost entirely sealed off by the heat retention collar design. By contrast,the Ratio Eight is an open brewing environment, and has its own brewing demands. Helweg felt the flat filters worked better in that closed environment.
It is interesting though that Ratio Six units sold in Europe come with a filter basket designed for Melitta style #4 cone filters.
With all this said, Helweg told me something that’s a bit of a scoop: Able Brewing is working on a flat filter design that can be used in the Ratio Six brewer (and other flat bottom filter coffee brewers).
Adding the flat bottom filter paper to the Ratio Six filter holder. Make sure it's snug in place.
Forget the Chemex
The Ratio six, like the Ratio Eight, practically begs to be used with a Chemex 8, 10, or 12 cup brewer: the shape just lends itself to using this tried and tested coffee brewer. And when you see photos of the Ratio Eight, at first glance, you think it is used with a Chemex. But it is not.
Ah, the dream - using a Ratio Six with your own Chemex. Not to be.
Both the Ratio Eight and Ratio Six are built with a magnetic sensor in the base where the carafe sits, to detect the carafe being in place. If you put a standard Chemex on it, the machine will not operate.
This is for protection, as well as a “pause and pour” feature. Protection from the machine operating and spewing out heated water everywhere when the carafe isn’t in place. The Six and Eight models also have a sort of “pause and serve” feature (you should never do this) in that, if you press and hld the soft touch button, it temporarily stops the water flow to the filter area, allowing you to remove the carafe, pour some coffee, then place it back on the base to continue brewing.
Back to the Ratio Eight and thinking it used Chemex brewers: Ratio makes a glass carafe that looks very similar to the Chemex, so it can use Helweg’s other company’s product: the Able Brewing Kone Filter. But the Ratio carafe is different: it has a magnetized base as part of its design, so it triggers the brewer’s carafe sensor properly.
The Ratio Glass Carafe with Kone Filter and magnetized bottom for use with the Ratio Six.
You can buy this carafe as an optional item (currently listed as pre-order) at Ratio’s website for the Ratio Six.
This might not please people who already own a Chemex and would like the option to use it with this machine. I suggested to Helweg that Ratio should sell (or include in the Ratio Six box) a metal disk that can trigger the sensor for people to use with their own Chemex brewer or other device, like a V60 and glass carafe.
About that Heat Retention Collar
I’m going to cover the heat retention collar a lot more in the full review of the Ratio Six, including some pros and cons of using it vs not using it, but for now, you should know using the heat retention collar is optional with this brewer.
But you probably should use it. The heat retention collar will better maintain the brewing temperature throughout the Ratio Six’s brewing cycle. The primary benefit is from the initial brewing phase: because it helps retain more heat, the start of your brew – as the coffee absorbs and dissipates the initial heat energy from the brewing water – gets up to full brewing temperature sooner with the heat retention collar in place and in use.
The heat retention collar fits on top of the filter holder, and has a soft, flexible upper collar for compressing against the underside of the dispersion screen area of the machine.
Warranty
Helweg is proud that the Ratio Six has a full five year warranty. He also wants customers to know there is a robust after-sales service available for the Ratio Six (and the Ratio Eight). “Warranty service is not a profit zone for us.” Helweg said. “We want our customers to be lifelong Ratio owners. We engineered the Ratio Six so that it should reliably provide trouble free service for at least 10 years (with normal descaling), and could possibly be a generational product, one you pass down to someone else.”
In this age of one year warranties, this is a refreshing take, and a bit reminiscent of Baratza’s phenomenal after-sales service (though Ratio beats Baratza on the warranty length).
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ConclusionRatio Six
If you’re all about doing a 250ml pour over day in, day out, the Ratio Six is not a brewer for you. Let’s just get that out of the way.
The Ratio Six is a small batch brewer. That’s its main modus – to deliver “batch” coffee, as in a litre or more so several people can have a cup – and to do it nearly as well as the best manual pour over techniques can deliver. If you live in a household with two or more coffee drinkers, and both of you demand a quality cup of coffee, this brewer is intended for you. If you want more than one big cup of coffee over a 1-2 hour period and don’t want to sacrifice (too much) quality, this is the brewer for you.
The Ratio Six is not without issues: it’s quite expensive, the carafe and lid could be better designed, and it would be better if the bloom stage was more programmable. But the positives of the brewer are numerous too.
It has a fantastically stable temperature delivery. The bloom works well for doing 800ml or more of coffee. The carafe really does retain coffee heat for a long time with an acceptable degradation in cup quality. The dispersion screen is one of the best on the market, for even saturation of the coffee grounds. I’m even sold on the flat bottom filter design considering you would use this brewer to do a litre or more of coffee. And the Ratio Six is a very unique looking, “work of art” for the counter.
In our full review, we’ll dive deep into temperature measurements, brew volume differences to taste, parts longevity and durability, blind cup comparisons to other auto drip coffee makers, a ton of usability discussion, and more. For now, this SCA-certified brewer is something we’d recommend to anyone who wants a high quality coffee for more than one person in a household. At $350, it’s not cheap, but if you amortize that over the 5 year warranty, taking into account a lot of $100, $150 brewers will fail within that time with daily use, this machine becomes a much greater value.
The Ratio Six is available via Amazon for $365. (this is an affiliate link; by using it, you are helping this website)
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