LINK Coffee Roaster

About LINK Coffee Roaster

Nucleus Link Sample Roaster

OVERVIEW

The LINK, manufactured by Kaffelogic in New Zealand, is a commercial sample roaster that can also be an excellent coffee roaster for home if you are accepting of its capacity of 100 grams of green coffee, typically yielding roughly 85 roasted grams.  That is about enough to brew 50 to 55 ounces of coffee.  While it is possible to roast a little more, it is really designed to function accurately in the 50 to 100 gram range and it does so very skillfully. Whether you’re a seasoned coffee taster, a farmer seeking direct feedback, or a curious enthusiast, the Link offers a unique roasting experience. This precision hot air roaster was developed largely by Sam Corra who was, among other achievements, a former Australian Barista Champion. LINK is built upon the physical framework of the Kaffelogic but beyond physical appearance they are wholly different products. Sam developed the 205+ included profiles.

As of this writing we have done about 100 roasts and we use it here whenever we need to roast samples.  We have also used it to roast some coffee for home.  What follows next is some general information about the LINK and some observations and pointers from using it on a first-hand basis. This roaster has been designed for light to medium roasts; it is not suited to dark roasting.

As detailed below, there are two applications that can be used with the LINK. One is an app for smartphone and/or tablet; the other a software program with other capabilities. Link App determines the profile that you will select for the roast. This is the only app that you really need since profile selection and other functions can be entered directly into the roaster manually. Link Studio software is a download from the Nucleus website and while it is optional, it adds a good number of enhancements to the process.  The roaster is connected to a PC or Mac computer via a type C USB cable. Thereafter, there is two way communication - but more on that later.

Coffee and modern technology come together to bring you The Nucleus LINK roaster. It is a highly innovative coffee roaster that offers both precision and flexibility for small batches of beans. At its core, the LINK aims to be a mobile sample roaster for home and professional roasters. The technology behind this roaster proves a commitment to quality, which can be noted from its presence at roasting and brewing competitions worldwide.  At last year's Specialty Coffee Association's event, a presenter roasted nearly 100 samples on two of these roasters for a cupping event the next day.  This attests to the reliability of the roaster as well as its speed doing back-to-back roasting.  On average, roasts reach first crack at about 6 minutes followed by development time of 45 to 70 seconds.  Cooling then takes about 4 minutes.

According to LINK, roasts can be cupped right away without additional time to degas and settle in due to LINK profiles.  We can neither attest nor dispute their claim, however, we have cupped a significant number of LINK roasts within hours after roasting and they seem to be fine for the purpose.

The LINK roaster comes with a really cool 'military grade' case that holds the roaster base, roast chamber, measuring cup (metal), density tube (metal), coffee sample tray and USB type C cable.  Every piece bears the LINK logo with the exception of the roasting chamber which has the Kaffee Logic logo on its top. That chamber is very effective at separating chaff during the roast.  Virtually all of the chaff is carried upward in the chamber from the roaster's fan and it is trapped inside the chaff collector section, which is easily removable for cleaning.  The entire case is fitted with high density foam with cutouts for each component.  Theis case is made for travel and portability.  The intent, in part, is to provide coffee growers with the ability to roast coffee on their farms, at varying altitudes, so that they can evaluate and adjust their production accordingly.  

Before you read further, we have to say that it sounds way more complicated to use this roaster than it is in practice. In fact, once you get used to determining density for your coffee, the roaster is very easy to use.

KEY FEATURES

• Customizable Roasting Profiles: The Link empowers you to tailor your roast to perfection. Through the LINK App, you can choose from a wide range of profiles, adjusting for simplicity or complexity. Density tube integration, process selection, and variety customization are at your fingertips.

• Travel Companion: The Link’s military-grade, water-resistant travel case ensures that you can assess coffee samples anytime, anywhere. Take it to origin, roast directly at the farm, and provide direct feedback to farmers for improved coffee quality.

• Precision from the Start: Each roast begins at room temperature, with the internal bean temperature matching the ambient roast temperature right from the beginning. This results in a more even roast, lower sample CO₂ levels, and an opportunity to taste the full potential of your coffee earlier.

• Adaptive Profiling: The core profiling system adapts to your current location, ensuring smooth operation regardless of external conditions or elevation. With over 205 core profiles available through the Link Studio software, you have the flexibility to customize your preferences and monitor modifications throughout the entire roasting process.

SOFTWARE

There are two software programs available for the LINK that work in tandem, though both are not required for successful roasts. The "LINK Nucleus app" is available for Apple and Android phones and tablets.  It is used to determine which profile is required when doing a roast and is also used for Fan Calibration. 

LINK NUCLEUS APP

Fan Calibration:  Calibration only needs to be done once if you will be roasting in one place.  Fan speed is adjustable based on altitude and electric supply (110v or 220v) so that there is roast profile consistency regardless of whether you are at sea level or high in the mountains.

Profile Selection: 

Before selecting a profile you are instructed to weigh 50 to 100 grams of coffee using the supplied Dosing Cup. Note: the most accurate roasts will be achieved at the higher end of this scale and to date we have performed all of our roasts using 100 grams.  Separately weigh and tare out the weight of the Density Tube. Once the weight has been noted, place the Density Tube in the sample tray and pour all of the contents from the Dosing Cup into it.  It should overflow.  The cap of the Density Tube is used to level the quantity of beans without force. Then weigh the now filled Density Tube and make note of it. That weight, in grams, will be entered into the app in order to determine the roast profile to be selected. 

Please note:  There were 2 versions made of the Density Tube itself.  Version 1, supplied with our test machine, will weigh more than 58 grams with the cap on it.  Version 2 is lighter and weighs under 58 grams.  You must know which version you have.  This was not well explained in the user manual. 

Once you know the density of the coffee about to be roasted, enter that gram weight and then select the closest processing method from a group of six choices (Natural, Anaerobic Honey, Anaerobic Natural, Washed, Anaerobic Washed and Honey).   Lastly, select the power supply, 110v or 220v.  There is a place to enter the varietal, but it is not being used at this time for other than as a personal note. LINK has plans for that in the future. Once done, you will be presented with a suggested "Profile Pack".

Here is an example:  After measuring and weighing a sample as noted above we determined that the density of a particular coffee was 68.  We open the LINK Nucleus app on our phone or tablet, choose Profile Selector and then New Sample Entry.  You will then be presented with four choices:  Cupping, Omni, Filter, Espresso.  Depending upon your intended use for the coffee you would select of these. One of the main variations is in development time.  Development time begins when you mark first crack and it is an additional percentage of time thereafter.  If your time from start to first crack were 6 minutes (360 seconds) and you chose a profile with 15% development time, that would add 54 seconds from the time you pressed the "first crack" button.

Cupping profiles:  typically presented with two choices based on density.  Profile D has 12% development time, B 15%, C 18%, A 10% and E 20%.  Profiles D, B and C are the most common but there are occasions where the remaining two are useful. 

   
Screenshots from the phone/tablet app

The control panel on the roaster. All roasting functions and profiles can be run directly.

LINK STUDIO SOFTWARE (PC or Mac)

While the LINK app on your tablet or smartphone is intended to provide you with the proper profile for your coffee's density and roast style, the LINK Studio software is somewhat akin to Artisan software with certain exceptions. The roaster is connected to your computer through USB with a type-C connector on the roaster end and a standard connector on the computer.  Once you click the plug icon in the software, a connection is quickly established. That brings up a log window with three tabs:  Logs, Profiles and Firmware. The Logs tab is where your most recently completed roast profiles are stored; the roaster's internal memory can store up to 300 such logs, but they can easily be moved to alternative storage should you need the space. The Profiles tab is where you select from hundreds of roast profiles. Lastly, the Firmware tab indicates which version of the software you have installed and provides the ability to update or re-install the latest version, periodically released.

There are about 40 core profiles and each is available with a version for Cupping, Omni, Filter, etc. Once you make your selection from the drop down menus on the Profiles tab, the information is immediately sent to the roaster and the data displays on LINK's LCD roaster screen. Now that the profile has been sent to the roaster, it is simply a matter of pressing the "play" button twice. The first press confirms the weight of the coffee being roasted and the second press starts the roast. You can now close the log menu and pay attention to the Roast Profile Curve window and especially the Log window which tracks the progress of the roast. As the roast progresses you can see how accurately the roaster follows the profile curve.  Most of the cupping roasts that we do here hit first crack in about 6:00 to 6:15 minutes. When first crack is reached, clicking FC from the Roast Profile Curve window starts the clock for development time.  At its end, cooling begins.

The idea of bringing world competition-level coffee roasting into the comfort of one's home w ith the push of a button is undoubtedly appealing to coffee enthusiasts. With its convenience and promise of high-quality, freshly roasted coffee, the Nucleus LINK is designed to cater to both the experienced coffee connoisseur and those new to the art and science of home roasting.

You may customize your roast to your liking by choosing from a wide range of roast profiles. After utilizing the complementary density tube integration tools, you can connect through the LINK App, select your desired process and variety, and navigate the roasting experience on your mobile device. 

Each roast starts at room temperature, with the internal bean temperature matching the ambient roast temperature from the start. This makes for a more even roast, lowers sample CO₂ levels and accelerates the realization of the complete flavor profile in your coffee.

Fan speed calibration transpires using the most appropriate setting for your current location in which the core profiling system—made up of over 205 profiles—operates smoothly and efficiently, regardless of external conditions or elevation. This, paired with live tracking technology, enables you with the flexibility to customize your profile preferences. With LINK, you can effortlessly monitor and document these modifications throughout the entirety of the roasting process.

The LINK roaster, density tube, dosing cup, sample tray, tasting top with detachable chaff collector, and USB cable can all be kept safely in a waterproof military grade case—all designed and manufactured in New Zealand. This allows you to easily assess coffee samples anytime, anywhere.

The LINK roaster comes with a rugged military grade travel case.

Why the Link?

The Link bridges the gap between science and artistry in coffee roasting. It’s not just a tool; it’s an exploration of flavors, a journey of discovery, and a way to elevate your coffee experience. Whether you’re a coffee professional, a farmer, or simply passionate about exceptional coffee, the Nucleus Link Sample Roaster invites you to unlock the nuances of each bean.

SPECIFICATIONS:

• DIMENSIONS: 
  • 4.75" (W) x 4.75" (L) x 17.75" (H)
     
• MATERIALS: 
  • Powder coated steel roast unit with plastic fittings (Nylon PA66)
  • Aluminium roast chamber
  • Double layer borosilicate glass hopper
  • Plastic (Nylon PA66) moulded body parts, & replaceable silicone seal

ROASTER IS NOT WATERPROOF.

Link User Manual (as of 2/29/24)

Please note the LINK roaster is shipped separately from coffee and other included items. Everything ships from the US East coast.