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New Process Development: Juice Drinks

New test methods developed, enabling raw material giveaway losses to be reduced by >£1m in 6 months


Food and Beverage – Juice Drinks


To improve process understanding and control in the measurement of sugars in solution in fresh juice drinks, in order to reduce false rejects and raw material giveaway.

Project Length:

6 months, 1 consultant


  • Raw material savings of over £1 million per annum
  • New test method developed with test equipment manufacturer

What inspired this manufacturer to pursue this project?

During a Chartwell-led problem solving training session, a client participant asserted that the industry standard refractive test for measuring sugars in solution was neither accurate or repeatable.  The participant used Fault Tree Modelling to establish a set of controlled conditions and proved that the inherent uncertainty lead to false product rejects, along with more than £1 million of material giveaway. This loss had been entirely hidden to the business.

Results of the 6 month project

  • Raw material giveaway losses reduced by more than £1 million per annum
  • The manufacturer of the test equipment released a game-changing test method

Key Workstreams:

Test Method Understanding:

  • The main technical challenge was to understand the science of refractometry and the difference between theory and real-world observation at a microscopic level.
  • The team started out by understanding how the test was supposed to work:
    • Sugars in the juice cause the refractive index of the liquid to change by a specific amount.
  • Next, the team analysed the problems that could cause inaccuracy:
    • Temperature - The temperature of the equipment and the sample caused micro convection which affects the refraction of the light.
    • Sediment - Any solids in the juice would settle on the prism, affecting the level of refraction.

Test Method Improvement

  • The team worked with the test equipment manufacturer to develop a working method that was robust for factory operations.
  • The new equipment filtered the sample and stabilised the temperature, prior to pumping the sample over a lens, taking continuous readings, to produce a repeatable and accurate result more than an order of magnitude better than the previous model.
  • More accurate readings enabled the juice-maker to better understand the composition of their product, ultimately allowing them to create a more consistent product that cost less to manufacture