Interested in a little light reading?

SCAA Item R4001 for Visual Grading

SCAA item R4001 consists of a light-weight black vinyl kit (10″ x 12″ x 1 3/4″) containing eight color disks, numbered in increments of 10 ranging from “Very Light” (tile # 95) to “Very Dark” (tile #25).

The kit also includes 2 background sheets, two standard Petri dishes for sample presentation for visual evaluation, and an easy-to-read manual. These (8) industry standard disks were designed to provide a visual guide for the degree of roast as a purchasing specification for both roasters and their customers.

Reporting in SCAA visual grades is inherently less precise than using Hunter L, a, b or CIE L*, a*, b* color values and correlated SCAA Coffee #. For best results using this visual coffee color evaluation system, you need to use balanced white light that minimizes the glare off the card and visually offset the texture difference between the roast ground coffee and the flat, uniform coffee standard. The SCAA # and Roast Classification system can perform well as a purchasing specification.

The HunterLab ColorFlex EZ Coffee meter comes with a built-in correlation to report both SCAA # and SCAA Roast Classification, as well as the HCCI – HunterLab Coffee Color Index used for roast process control.

HCCI – HunterLab Coffee Color Index measures the reflectance of ground coffee products at 640 nm, which is optimal for defining the degree of roast.

HCCI works best for measuring during the roasting process, taking the coffee product to a consistent end point.

HCCI = [HCCI_slope * R%(640 nm)] + HCCI_offset

where default coefficients for HCCI_slope = 1.958 and HCCI_offset = – 3.32.

HCCI* comes with a user-adjustable bias and offset in each setup to allow display in agreement with existing instruments.

HCCI values are typically displayed to 1 decimal place.

HCCI correlates well with the visual SCAA Roast Standards and exhibit 20 unit range.

The HunterLab ColorFlex EZ Coffee meter comes with a built-in correlation to report HCCI – HunterLab Coffee Color Index, SCAA # and SCAA Roast Classification, all used to quantify the degree of coffee roast.

HunterLab ColorFlex Coffee with HCCI# with correlated SCAA# and SCAA Roast Classification displayed.