Creating better coffee

The LINK roaster is designed upon three main pillars: technology, practicality and affordability.

Able to be transported anywhere in the world, the precise software of the LINK enables you to create consistent, quality roasts anywhere, anytime.

LINK features

The altitude at which you roast coffee will affect the roasting process – for this reason, the LINK includes an Altitude Calibration feature so you can adjust it to your needs, no matter where you are. 

The altitude calibration feature gives LINK users the ability to trim the fan speed of the roaster. This allows an increase or decrease the oscillation of the coffee’s movement for each sample without affecting the initial factory calibration.

The primary developer of the LINK, Sam Corra, created a specific calibration process exclusive to the LINK. This is key to running the profile selector app and ensuring consistency between different units, as well as being able to tolerate smooth roasting at varied altitudes wherever you take the unit.

Within the LINK app, there is a calibration mode featuring an algorithm that was created by our team while travelling in high-elevation coffee farms, collecting data about how each roast behaved. This allows the user to set the roaster fan oscillation to mimic roasting at sea level at any altitude. This allows the provided core profiles to roast the same regardless of where you take the unit making it one of the first truly portable sample roasters on the market.

The companies that developed the LINK – Nucleus Coffee Tools and Kaffelogic – worked on an updated pc board to hold all roast profiles.

The LINK Unit comes with 700 profiles for filter and cupping, that are exclusively accessible through the LINK software. These core profiles have been developed to have a solution for all types of coffees you could encounter on your coffee journey. This algorithm was refined over the last 3 years through various origin and competition travels. On these trips, the profiles were not only designed but also extensively tested and refined to ensure they would generate a globally performing roast for cupping.

Each Roast Profile is represented as a number, eg. 206.5

Within the LINK, an Nucleus Coffee Tools-specific firmware reformat allows the user an option to customise a batch size between a select range of 50g to 100g.

The custom batches increase in 1g increments and calibrate the fan based on the input, so it can run off the same core profile sets, regardless of green input between that range. Selecting your batch size is the final step in the process before the roast commences, and can be adjusted using the + and – symbols on the LINK roasting unit before hitting start (the centre, triangle button).

We do not recommend roasting more than 100g of coffee per batch, as this will effect the quality and effectiveness of the roast profile.

The LINK App uses a variety of data to determine and recommend roasting profiles. One of the key elements is Density measurement, which is done using the Density Tube that comes with the LINK roaster.

Watch the video below to see how the density measurement works:

The LINK app also has an “Advanced Dial-in” function that can be utilised after the initial roast to further refine the profile selection of specific samples.

For example, if the initial roast of a coffee was slightly off perfection, or wasn’t quite what you wanted to achieve, the Advanced Dial-in system will analyse all relevant information from that roast and will suggest a more appropriate profile.

See more below:

DTR stands for three things: “Development Percentage” (D), “Time of roast” (T), and “Roast degree” (R).

DTR was designed to be a reactive intelligence bot, automatically adjusting to the different variables of each roast when the first crack is logged. The DTR override system will adjust the termination at the exact development % and range of temperature increase range outlined.

This means that if a 1st crack is lodged early or late, the overall parameters of the roast will remain the exact same.

The 700+ roast profiles for the LINK system are divided into different ‘Profile Packs’, which are determined by the roast goal (Cupping, Filter, Espresso or Omni). Each Profile Pack is designed to achieve different results depending on the roast goal.

When selecting profile with the LINK App, a Profile Pack will automatically be recommended and will be determined by the data entered into the app.When using the Advanced Dial-In feature on the LINK App, users are able to customise their roast profile by selecting a Profile Pack, the time of first crack (FC), and the start profile to base the roast from.

Watch the video for a more detailed explanation of each Profile Pack, and read more below.

Profile Packs

For roasting Cupping samples, the difference between each Profile Pack is the development percentage and the roast curve pitch for each profile. Having 5 variations allows the user freedom of choice in roast expression.Each Profile Pack is designed to best suit the expression needed for that specific coffee sample being roasted, or to the personal style or preference of the people assessing the sample.

Each Profile Pack follows a specific development percentage, rate of rise increase, time of first crack and arc of the roast curve. As there are 5 different “packs’, this allows 5 variations of the 41 core Cupping profiles, giving the user the freedom to adapt their preference of taste or purpose of use.

Each profile pack is differentiated by a letter (A,B,C,D,E). This letter will be present after the profile number e.g. 213 NCT (D), and the percentages refer to the DTR %.

A 10% PACK

  • More delayed crack to focus on more time spent in Maillard and the sugar browning phases, with 10% DTR
  • Best suited for those who like a more Scandinavian-styled roast approach, where the focus is on acid forward profile with a vibrant, clean and light body.
  • These profiles are also well suited for heavier fermented or extended- time processing methods.

B 15% PACK

  • These profiles have a good balance between the pitch of heat applied prior to 1st crack occurring to control the time developing your coffee attributes, versus the amount of time spent after 1st crack breaking down the acidity intensity and caramelizing the sugars of the profile.
  • Best suited if you want a slightly fuller body with more caramelized, over fresh, expression of flavours.
  • This pack is a great all-around go-to especially for washed process coffees, and cleaner, more classic natural and honey-processed samples.

C 18% PACK

  • These profiles are designed to get enough development and heat energy into the coffee at a slightly earlier point so that more time can be spent post 1st crack. This rounds out the intensity of the coffee to give the most similar experience to a traditional gas-roasted sample.
  • This expression is for someone looking for a profile that is most familiar with full-body, integrated acidity, and rich caramelized sugars.
  • The profile expression mimics most like a traditional gas sample roast in body.
  • This is also a great starting point for omni-style espresso that lean to the more acidic bright expression whilst being a clean and balanced filter coffee.

D 12% PACK

  • These profiles are designed to be your default pack that will generally suit a fair expression for all styles of coffee.
  • They are the most balanced in the time 1st crack should fall and the time spent in development % whilst optimising roast stability and control.
  • These profiles are best for all-around cupping and filter expression. This pack provides a fair and honest expression of any process or variety of coffee.
  • This should be your reliable go-to if ever in doubt, as it will always give you the best reference point.

E 20% PACK

  • These profiles are designed to allow the most time possible within the optimised overall roast time after the point of 1st crack to break down acidity intensity and completely caramelise available sugars.
  • These profiles have the most aggressive heat application to the arc and pitch of the roast-curve to force an earlier cracking point whilst controlling the roast degree to a slightly darker point.
  • This expression is best suited for someone looking for a rich espresso-tailored, omni-style profile that will still work well for a fuller-body, richer filter.

Each filter Profile Pack is designed to have a suitable roast plan to maximise the different characteristics of density ranges and processes. No matter how different a coffee is from farm, process, variety country or region, the LINK has a solution to give the perfect approach for filter brewing.

The Filter Packs A, B and C are designed to optimise roasting for filter extraction off your LINK. The style of these profiles mimics the roasting theory used by LINK developer, Sam Corra for his 2017 WBrC runner-up presentation in Budapest.

The primary difference in these roast approaches compared to the Core profiles is how the body articulates in the cooler stages. These profiles are designed for rested filter coffees served 3-14 days after roast and target assessment brackets outlined in the WBrC Competition Scoresheet. The main difference between (A), (B) (C) is the ROR Pitch, roast time and first crack time.

  • For more acidity, clarity and brightness, we suggest utilising the (A) Filter Pack.
  • For more body, weight and texture-driven look at utilising the (B) Filter Pack.
  • For low to mid dense anaerobic or classic processed naturals, as well as high density washed and honey we would suggest (C) Filter as the best all rounder to start on.

There are currently 3 espresso options. Like filter packs, each is designed to allow an espresso solution for any coffee variety and process. the espresso packs can be used to accommodate a specific approach to extraction or coffee style of the user.

Espresso A:

  • Slower style roast producing lower acid, fuller bodied espresso.
  • Recommended recipe range 21-22gm in, 38- 40gm out 22-25 seconds

Espresso B:

  • Medium-style roast-producing creamy, balanced, medium-acid-style espresso.
  • Recommended recipe range, 20-21gm in, 44-48gm out, 20-23 seconds.

Espresso C:

  • Gentle-style roast-producing light-bodied, brighter style espresso.
  • Recommended recipe range, 19-20gm in, 44-48gm out, 25-28 seconds

The Omni pack is for the barista and coffee lover on the go or looking for flexibility on how to extract their roasts. Whether you want something more espresso or filter-focused, this is a great user-friendly profile pack to allow you to undertake multi-purpose roasting with one Profile Pack.

You can select a development range right at the end of the filter range and the start of espresso ranges for use over both extraction styles and can lean more towards one development % (DTR) range if you are focused on just one extraction style. The choice is really yours.

An additional benefit is the slightly faster roasts, which mean these will usually be more expressive straight off the roast.

Firmware

The LINK roaster and accompanying LINK Studio is built on specific firmware – permanent software that is programmed into both into a read-only memory.

Since the release of the LINK, there have been multiple updates to this firmware in order to provide more accurate roast profiles, extend profile packs, and add new features for LINK users to utilise in their roasting experience.

With each firmware update, users are provided with a prompt in the LINK Studio (when connected to the internet), and are able to update with ease. Each additional firmware update builds upon previous updates – however, these previous updates remain accessible to users in the LINK Studio, should they wish to use them.

Previously, these updates were referred to as ‘versions’ and assigned a numerical value – Version 1 (V1), Version 2 (V2) and so on. In upcoming updates to LINK firmware, these versions will move to a Operating System (OS) based program, and will be identified by different names (eg. Yemeni, Cauca). These names refer to different coffee-growing regions, places and cultures in the world, in honour of the diverse and wonderful global coffee community.

Number of profiles41

Number of packs1

Duration Used: December 2019 – March 2022

Description: The initial version of the LINK was developed with 1 core profile pack and inbox for cupping. This profile style was all based around a roasting style and theory that would eventually become the A 10% cupping style in future versions.

Number of profiles: 205

Number of packs: 5

Packs: Cupping: A10%, B15%, C18%, D12%, E20%

Duration Used: March 2022 – March 2023

Description: With the first official version of the LINK roasting firmware, NCT Core (V1), we introduced the idea of 5 different roast plans for cupping. These different roast plans all had the same termination point, but were placed around with different times spent in maillard and development phases. This version is where we introduced the lettering system of profile Packs (A, B, C, D, E).

Number of profiles: 389

Number of packs: 9

Packs:
Cupping: A10%, B15%, C18%, D12%, E20%
Filter: A, B
Espresso
Omni

Duration Used: March 2023 – December 2023

Description: The second version of the LINK firmware, Minas, was an expansion on the concept of the previous version (Yemeni) by keeping the same functions and profiles for the 5 cupping Packs. However, it also added new workspaces that catered for other roast styles, including Espresso, Filter, and Omni styles. In this update, all profiles underwent a makeover to accommodate for performance improvements to level ranges and Rate of Rise (RoR) minimums.

Number of profiles: 435

Number of packs: 10

Packs:
Cupping: A10%, B15%, C18%, D12%, E20%
Filter: A, B, C
Espresso
Omni

Duration Used: December 2023 – current

Description: The ‘Cauca’ update to the LINK roasting system was released was a surprise update for Christmas 2023, to add a new space for a new profile pack (Filter C). It was also a time when the team further improved the other 9 profile packs and their preheating ranges, in order to allow for the best operation and suggestions to be made by the LINK algorithms when it comes to (i) profile selection and (ii) recommendations on which profile pack to use.