How to Calculate PAC Dosage for Color Removal in Sugar Syrup

Powdered activated carbon (PAC) is widely used for color removal in sugar and syrup refining. The most frequent question is “how much should I dose?” There is no single correct answer; dosage depends on many variables and is best determined in the laboratory.

What Does Dosage Depend On?

• Initial color (ICUMSA) and the targeted output color.
• Syrup brix (dry-solids ratio) and viscosity.
• Temperature and contact time.
• PAC activity (molasses/methylene blue) and particle size.

A Practical Dosage Approach: The Jar Test

The most reliable way to find the right dosage is a jar (adsorption) test: take several samples of the same syrup, add increasing PAC doses (for example, different percentages on a dry-solids basis), mix and filter at the same temperature and contact time, and measure each sample’s ICUMSA color. The dose–color curve clearly shows the lowest economical dose that reaches your target color. Typical dosage ranges vary greatly by application, so base your decision on your own syrup’s test result, not a number from the literature.

Tips That Improve Efficiency

Ensure adequate contact time and homogeneous mixing; keep the temperature in the appropriate range for the process (higher temperature usually improves both adsorption and filtration); use PAC together with a filter aid to speed up filtration. Choosing a food-grade PAC with the right activity lets you reach the same color target with a lower dose.