What are the NCI National Cheese Color Standards?

“Monterey Jack cheese….natural white, not darker than #2 using the National Cheese Institute Color Chart … Cheddar cheese….natural color, not darker than #9 using the National Cheese Institute Color Chart…” www.farmdale.net

“…initial point of sale for: Cheddar cheese in 40 pound blocks, colored between 6 and 8 on the National Cheese Institute color chart…” www.cmegroup.com

“…Feta is white in color, is a bit sour to the taste and rich in aroma … Fresh Asiago has an off-white color and is milder in flavor than mature Asiago. Mature Asiago also has a more yellowish color and is somewhat grainy in texture … Cream cheese is usually white in color and is available in low-fat or non-fat varieties … Blue cheese….is spotted or veined throughout with blue, blue-gray or blue-green mold, and carries a distinct smell….” www.idfa.org

The National Cheese Institute’s Color Standards are a series of 12 Munsell color chips initially intended for the visual color grading of hard cheese.  Additionally it has been applied to the color of products from soft cheese spreads to condensed milk.

The National Cheese Institute is part of the US International Dairy Foods Association (IDFA), which also represents the Milk Industry Foundation and the International Ice Cream Association.

The color quality concern for cheese products is color uniformity within a lot, and color consistency from lot-to-lot.

In a well-lighted area, preferably daylight balanced, a person would assign the nearest NCI grade based on a visual comparison between the printed chart and the sample cheese color.

The NCI Cheese Color grade provides a more systematic and consistent method of color communication for cheese products than the random vocabulary of individual people and serves as a basis for purchase of large quantities of cheese products.

Source for NCI National Cheese Color Standard Chart

The NCI chart is commercially available from:

Nelson-Jameson Company, Marshfield, WI 54449 USA www.nelsonjameson.com  (Product # 170-4900)

Degussa BioActives, Waukesha, WI 53187 USA www.foodingredientsinc.com

FAQ: “Do you have Hunter L a & b values that correlate to the NCI cheese color standards? We have NCI Color specifications for our cheese products. I would like to translate them into Hunter Lab specifications… so that we can get continuous rather than categorical data and better control our quality. The NCI Color chips are too small to cover the Hunter window… so we can’t just scan it…”

We view the NCI Color Scale as a visual matching and reporting scale with less precision (only 12 steps) than a colorimetric color scales that come with your color measurement instrument. If you stay with the intended use of this scale which was to visually categorize cheese color for product contractual description, it works fine.

You would think it would be easy to develop a colorimetric correlation to the NCI Cheese Color Scale by directly reading in the cheese color chips in Hunter L, a, b or CIE L*, a*, b* on your instrument and then working out a direct correlation to this NCI visual scale. This is not the case.

There is a difference between the cheese color chips which are solid and opaque and block cheese is slightly translucent (or light trapping). This introduces a bias in your measured values to visual NCI assignment such that if you have a cheese sample that is a perfect visual match to one of the NCI color chips and you measure both chip and cheese, you will find that the measured color values will not be the same. Light is being slightly trapped in the translucent cheese and distorting the measurement match.

The best way to create an NCI Cheese Color correlation to measured color values is to take a wide range of cheese samples covering as wide a range of NCI color as possible. Using a group of cheese color experts, visually assign NCI Color ratings (average group opinion is best) to the cheese samples using the visual NCI Color chart. Then measure the cheese samples on your HunterLab instrument using Hunter L, a, b or CIE L*, a*, b*. Develop a correlation between the measured cheese values and the visually assigned NCI ratings for those same cheese samples.

NCI Color is a single 12-step reporting scale common to the cheese industry but less precise than 3D colorimetric color scales such as CIE L, a, b* or Hunter L, a, b. If you are looking to verify color consistency in your cheese product over time, the best way is to use CIE L, a, b* or Hunter L, a, b color measurement which will tell you more about the lot color variation of your product and with greater precision.

If you develop an NCI Color correlation using the above method, you can report this in addition to clients who wish this NCI rating. Alternatively, you can assign an NCI color rating visually.