A Souper’s Guide to the Oxo Rapid Brewer (ORB)
or An ORBer’s Guide to Soup?
The Basics
Soup is a coffee brewing method that pushes the water through a puck but where the coffee is ground coarser than for espresso such that no or very little pressure builds up during the shot (generally less than 1 bar) yet the flow rate is high. In addition, the puck is soaked as gently as possible at the beginning of the shot in order to avoid compressing the puck, which helps overall extraction and obtaining a high flow rate.
Grind
Generally speaking, you want the grind to be somewhere between pour over and espresso. Going coarser tends to increase clarity at the cost of body / texture. Going finer tends to increase body / texture at the cost of clarity.
You might hear that you want to start with a gap of 450um, or that you want “double a turboshot” or “half a v60”. These are all fine reference points if you’re familiar enough with your grinder to know what that means.
Note: Asking how many clicks on a specific grinder is usually not very beneficial. There are too many other variables for someone to be able to reliably tell you what to set your grinder at. These include: differences between individual grinders of the same model, the origin of your beans, the roast level of your beans, etc.,
If you’re not familiar enough with your grinder or you haven’t yet dialed in your particular bean for a v60 / turboshot, the best way, in my opinion, is to coarsen the grind until water drips through the bed while you’re filling the water. Then, tighten up the grind until it just doesn’t drip until you rest your hand on the plunger.
That tends to be an excellent starting point for a wide variety of beans and should give excellent flavor and clarity, if not your particular preference of body / texture. But this is really just a starting point: the whole range of grind settings that allow for gentle soaking and then a relatively fast flow rate produces interesting soup. It just changes character and brings out different characteristics of the coffee: experiment!
Soaking
This concept is similar to the idea of “pre-infusion” from espresso or perhaps “bloom” from pour over. Essentially, though, before we begin fully extracting the shot in earnest, we want to wet the bed thoroughly… no pun intended.
After filling the water reservoir, quickly screw on the pump and begin to slowly, gently, and consistently press down on the plunger. You will know that the soak is complete when the bottom of the screen is coated evenly with coffee.
An ideal soak would:
- Require very little pressure
- Require a single press (or less) of the plunger to evenly coat the screen
- Coat the screen either simultaneously or in a donut pattern (i.e. an outer ring that fills toward the center)
The most common culprit for not accomplishing any of these 3 criteria is grinding too finely.
My personal experience and the feedback I’ve had from helping others seems to suggest that it’s always better to be too coarse and adjust finer to target your desired body than to start fine and try to fix issues by other means.
As a reference for what I mean when I say gentle, I try to grind coarse enough to where the weight of my hand on the plunger is enough to drive the soak.
Finally, I noticed a phenomenon where people often want to rush the end of the soak. I would encourage you to be patient and consistent and wait for the plunger to fully depress with gentle pressure. Then you can really drive the flow and finish out the extraction.
Dosing / Ratio
The ORB seems to be very comfortable in the 15g ~ 30g range. Some people have gone as low as 10g or as high as 40g and reported excellent shots, but the norm seems to be 20g ~ 22g (especially after Lance Hendrick’s SOUP Guide where he recommends 22g).
As for the water ratio, people have reported success with everything from 1:2 to 1:8, but a good starting point is 1:4.
The workflow of the Rapid Brewer is such that you tend to use all of the water that you add to the reservoir. Most of it will pass through, but some water will be retained in the coffee grounds. Therefor, the coffee:water ratios are often expressed as the input ratio – that is, the amount of coffee added to the basket vs the amount of water added to the reservoir.
This differs from what you might be used to with an espresso machine which is typically output ratio – that is, the coffee added to the portafilter vs the amount of water that ends up in the shot glass. Terminology has not yet been nailed down, but this might be considered the yield. When dialing in a new coffee or comparing brews with other people (especially if they use a different type of machine), it will likely be more useful to compare the output ratio / yield.
Also, as a quick note, the water reservoir tends to rapidly cool the water. So using water that is just off the boil is a good starting point as well.
Beyond the Basics
Filters
Many, if not most, people tend to use paper filters with the ORB.
A bottom paper filter can help catch fines and give a profile closer to pour over. A top filter (not necessarily paper) can help distribute the water for more uniformity.
The stock basket has a rather strange geometry with a 64.5mm inner diameter (ID) at the top and a 62.5mm ID at the bottom. There is also a chamfer (or taper) at the bottom that narrows to 58mm.
If you want to simplify things, you can use a 2.5 inch diameter filter for both the top and the bottom. There are 2.5 inch circle punches available that people have had success with on chemex filters or, for an even simpler source, aeropress filters are 2.5 inches.
You can also opt to use 58mm paper filters on the bottom and they’ll cover the screen perfectly.
Finally, if you prefer to get some exact, custom filters you can use an adjustable circle cutter.
If you find that the top of your puck is often lop-sided or has holes dug into it, the most likely cause is from pouring the water to fill the reservoir. A simple solution is to get a 58mm puck screen and drop it into the water reservoir, then pour on top of it. It’ll break up the flow and leave the top surface undisturbed!
Espresso Baskets
A common request that people have is to use an espresso basket in the ORB. This can be done quite easily with a 58mm basket, as most sit perfectly on top of the stock basket. However, you’ll need an additional O Ring or Gasket to prevent leaking. Some commonly purchased ones are:
- 70mm O Rings - https://www.amazon.com/dp/B07CVL598T
- Mason Jar Lid Gasket - https://a.co/d/8yxAzqU
Either one will work fine. This video can help clarify how everything fits together if you’re having trouble visualizing it.
Alternatively, if you prefer to use a 51mm or 49mm basket and own a 3D printer, here is an adapter that interfaces with the stock O Ring above the threads of the water reservoir.
The biggest problem with this arrangement, though, is that you can’t see the bottom of the espresso basket when performing the soak. To alleviate this, there are 3D printable open bottom ORB Baskets available here and here
Buffer (aka Custom Water)
People are often either shocked at the acidity that can be present when souping or they expect to get blasted with acidity and find it lacking. Assuming that you’ve followed the initial advice regarding the grind and soak, then light (and even some medium) roasts should be have vibrant, juicy acidity.
If you find that acidity to be more like battery acid than pleasant and sparkly, then your water may be too soft and you’ll need to add buffer to your water.
On the other hand, if you find that the coffee is rather flat and lifeless, then your water may be too hard and the alkalinity is buffering out the natural acidity of the coffee.
To remedy both of these solutions, you can mix your own water. This is a huge topic that you can explore much more deeply on the EAF wiki / discord, but I want to give you a baseline to explore to get started. A ten-thousand foot view of water alkalinity can be broken down into GH, KH, and the GH/KH ratio.
GH is the General Hardness of your water and is a measure of calcium and/or magnesium ions that are present. Generally speaking, and this is a vast over simplification, you can interpret higher amounts of GH with more compounds being extracted from the water. (This is not really true at all, but is repeated often and is a close enough mental model, despite being inaccurate)
KH is the Carbonate Hardness of your water and is measure of carbonate and/or bicarbonate ions that are present. KH is directly responsible for reducing the intensity of acid notes in the resulting cup.
When making water for coffee, the water is described in terms of GH/KH as parts-per-million (ppm). A common light roast recipe is Holy Water which is 60/23. That is, a given volume of Holy Water will have 60ppm magnesium/calcium ions and 23ppm carbonate/bicarbonate ions.
Common sources for GH are Magnesium Sulfate / MgSO~4~ (aka Epsom Salt) and Magnesium Chloride / MgCl~2~.
Common sources for KH are Sodium Bicarbonate / NaHCO~3~ (aka Baking Soda) and Potassium Chloride / KHCO~4~.
Finally, when dealing with any custom water recipes you need to start from a source of water that has 0ppm GH and KH. This can be distilled water (bought at the store or distilled yourself), RO water (store-bought or from home), or zero water (water that has been filtered through a ZeroWater filter or equivalent).
To make things easy for mixing up various recipes, we can create concentrates that will add 1ppm in a one liter with the following formulations:
- (GH) Magnesium Sulfate / Epsom Salt - Mix 2.46g in 1 liter of distilled / zero water
- (GH) Magnesium Chloride - Mix 1.90g in 1 liter of distilled / zero water
- (KH) Sodium Bicarbonate / Baking Soda - Mix 1.68g in 1 liter of distilled / zero water
- (KH) Potassium Bicarbonate - Mix 2.00g in 1 liter of distilled / zero water
Now, to make your custom water recipe subtract the GH ppm and the KH ppm from 1 liter and add that much distilled / zero water to dilute. Using Holy Water again that would be:
60ml GH Concentrate + 23ml KH Concentrate + 917ml Water = 1L Holy Water
Troubleshooting
Shot is Too Sour
Try grinding coarser
Shot is Too Bitter
Try grinding coarser
Shot is Astringent
Try grinding coarser
Shot is Overextracted
Try grinding coarser
Shot is Underextracted
Try grinding coarser
Shot is Unbalanced
Try grinding coarser
Shot is Too Weak
Try grinding coarser … Unless it drips before starting the soak, in which case try grinding a bit finer
If any of the above fails to resolve the issue, then you can try adjusting the water temperature, buffer, or ratio.
The real lesson to take away here is to really try to focus on surfing that no-drip boundary and practicing a gentle soak. That will be the first thing people ask about and advise when asking for help on the EAF Discord, so take some time to explore that. If you’re still struggling after that, then please reach out for help! We would love to help you discover the wonder that is soup!