IDDSI Testing Methods
IDDSI tests are intended to confirm the flow or textural characteristics of a particular product at the time of testing. Testing should be done on foods and drinks under the intended serving conditions (especially temperature).
The IDDSI systematic review suggested that liquids and food should be classified in the context of the physiological processes involved in oral processing, oral transport and flow initiation (Steele et al., 2015). To this end, different devices are needed to best describe the behaviour of the bolus.
Drink Testing Method: The IDDSI Flow Test
When evaluating drinks and liquidized foods, IDDSI chose a gravity flow test using a 10ml syringe, as a simple, easy to use, practical objective measure to classify drinks based on their rate of flow. The standardised IDDSI Flow Test has been used internationally to categorise a wide range of liquids reliably, in agreement with currently existing laboratory tests and expert judgement. It has been found to be sensitive enough to demonstrate small changes in thickness associated with change in serving temperature.
Please see our playlist below for demonstration of testing methods for different drink levels:
Food Testing Methods
IDDSI provides testing methods that use common eating utensils to minimize the need for subjectivity that often accompanies description-based methods. Forks and spoons were chosen as they are inexpensive, easily accessible and available in most food preparation and dining environments. A combination of tests may be required to determine which level a food fits into. Testing methods for purees, soft, firm and solid foods include: The Fork Drip test, Spoon Tilt test, Fork or Spoon Pressure Test, Chopstick Test and Finger test.
Fork Drip Test
The Fork Drip Test is used to check the correct thickness and cohesiveness in Levels 3-5 foods by assessing whether they flow through or how they hold together on the slots/prongs of a fork and comparing against the detailed descriptions of each level.
Spoon Tilt Test
The spoon tilt test is used to determine the stickiness of foods (adhesiveness) and the ability of the food to hold together (cohesiveness).
Fork Pressure Test and Spoon Pressure Test
To check how firm or hard a food is, a Fork Pressure Test is best used to assess foods in Levels 4-7EC and transitional foods by assessing how the food changes when pressure is applied to the food with the tines/prongs of a fork or the back of a spoon. The slots/gaps between the tines/prongs of a standard metal fork typically measure 4 mm, which provides a useful measuring tool for particle size of foods at Level 5 – Minced & Moist.
Important: Please note that the particle size differs for young children. Refer to the Complete IDDSI Framework and Detailed Definitions.
If forks are not available, chopsticks can be used to pick up and break apart food to determine its characteristics and behaviour.
Finger tests have been incorporated in recognition that this may be the most accessible method in some countries.
Please see our playlist below for demonstration of Testing Methods for different food levels: