When purchasing sugar, the first and perhaps most essential system one must learn is the ICUMSA Ratings System. Overseen by the International Commission For Uniform Methods Of Sugar Analysis, ICUMSA Ratings are standardized ratings that enable traders from all over the globe to accurately describe the quality of their produce.
Based on a colormetric assessment, ICUMSA Ratings essentially reflect how white a sugar is, and therefore how refined and high quality it is. The sugar refining process that removes both impurities and the brown color from sugar results, in optimal conditions, in producing top quality sparkling white sugar known as ICUMSA 45. ICUMSA ratings can also be used to rate raw sugars, with ICUMSA ratings sometimes heading to ICUMSA 4000 and beyond.
The ICUMSA test is generally carried out with a tristimulus colorimeter that takes readings of how much light is absorbed by the sugar. Raw sugar absorbs a great deal of light, whereas refined sugar absorbs very little. The colorimeter is capable of quantifying exactly how much light is absorbed and generating a replicable reading based on this data.
Whilst the ICUMSA ratings system is a global standard, there are some jurisdictions, Europe in particular where the system has been reversed, and ICUMSA 42 refers to raw sugars. The more often used system, where ICUMSA 45 refers to highly refined white sugar is referred to as the Brazilian SGS system. Most purveyors of sugar will note whether they are using the Brazilian SGS system, but if you are in any doubt, inquire as to the ratings system being used.
Here is a break down of some of the most common types of ICUMSA rated sugars commonly sold. Please note that these are by no means hard and fast grades, and that you may encounter sugars which fit between these grades, or have requirements for sugars falling outside them yourself.
Refined Granulated Sugar
This is the standard for commercial sugar sold to consumers in most western nations. This sugar has undergone rigorous refining and is the most safe sugar for human consumption. In some cases, it may have brown color added to it to create safe “brown” sugar. One can find ICUMSA 45 in supermarkets, eateries, and in the homes of millions of people worldwide.
Extra Special Crystal Sugar
ICUMSA 100 – 150
This sugar does not quite have the sparkling color of ICUMSA 45, nor the quality, but is still a food grade sugar and is quite often used in the manufacturing of drinks and foodstuffs.
Special Crystal Sugar
Also food grade sugar, once again, less refined than the previously listed ICUMSA grades, but is used in food applications where a lower grade of sugar is acceptable.
Consumable Raw Sugar (Brown Sugar)
This is the absolute limit when it comes to consumable sugars. Though this sugar is a brown color, it is generally not the same brown sugar sold in many places in Western Countries. Brown sugar is, in those cases, typically ICUMSA 45 sugar with colorant added. Some prefer to consume raw sugar however, and in those cases sugars in the ICUMSA 600 to 800 range are often used. Any sugar with a rating higher than ICUMSA 800 according to the Brazilian SGS system should not be consumed by humans as it contains a great deal of bacteria and contaminants that can lead to illness.
ICUMSA 1600 – 2000
This sugar is suitable for refining, but should not be consumed by humans.
Very Raw Sugar
ICUMSA 4600 MAX
The rawest form of sugar. Likely to contain high levels of contamination, must be refined to be of any use in most applications.