A Just-About-Right (JAR) scale in Food Technology is a type of sensory analysis used to determine whether a characteristic of a food product is too much, too little or just right.
Unlike a hedonic scale, which measures how much a person likes a product, a JAR scale helps us to identify exactly which characteristics may need improvement.
JAR scales are particularly useful when developing recipes and making healthier modifications, such as reducing sugar, salt or fat. Think about Goldilocks and her porridge!
What is a Just-About-Right (JAR) scale in Food Technology?
A JAR scale is a sensory evaluation method where testers score a specific characteristic according to whether they believe it is:
- too little
- just about right
- too much
For example, when testing a biscuit recipe, students may evaluate:
- sweetness
- saltiness
- crispiness
- softness
- flavour intensity
- moisture content
A typical JAR scale might look like this:
| Score | Meaning |
|---|---|
| 1 | Much too little |
| 2 | Slightly too little |
| 3 | Just about right |
| 4 | Slightly too much |
| 5 | Much too much |
Why do we use JAR scales in Food Technology?
JAR scales are useful because they:
- identify specific areas for improvement
- support product development
- provide numerical data
- help justify recipe modifications
- identify consumer preferences
- allow healthier recipes to be evaluated effectively
They are widely used in food science and commercial product development.
Example
Imagine you have developed a reduced sugar cake recipe.
You ask testers to evaluate the sweetness using a JAR scale.
| Tester response | Number of testers |
|---|---|
| Much too little | 2 |
| Slightly too little | 6 |
| Just about right | 4 |
| Slightly too much | 0 |
| Much too much | 0 |
This suggests that the cake may not be sweet enough and that further development of the recipe may be required.
Common mistakes when using JAR scales
One of the biggest mistakes students make is confusing a JAR scale with a hedonic scale.
A JAR scale does not ask:
Did you like the product?
Instead, it asks:
Was this characteristic too little, too much or just right?
Another common mistake is trying to evaluate too many characteristics at once. JAR scales work best when focusing on one characteristic at a time.
Advantages of using a JAR scale
- Identifies specific areas for improvement
- Produces numerical data
- Useful for product development
- Supports recipe modification
- Easy for testers to understand
Disadvantages of using a JAR scale
- Does not measure overall liking
- Results can be subjective
- Requires careful planning
- Only measures selected characteristics
When should I use a JAR scale in Food Technology?
JAR scales work particularly well when:
- reducing sugar
- reducing salt
- reducing fat
- developing healthier recipes
- modifying existing products
- investigating food science concepts
- carrying out practical investigations
JAR scales and healthier food products
JAR scales are particularly useful when developing healthier recipes.
For example, if you reduce the amount of sugar in a biscuit recipe, testers can evaluate whether the sweetness is still acceptable.
Similarly, if you reduce salt in a savoury product, testers can decide whether the level of seasoning is too low, too high or just about right.
This allows recipe modifications to be made more accurately and helps justify changes during product development.
Create your own JAR scale
Want to create your own printable JAR scales?
Try our free Sensory Analysis Toolkit, which allows you to generate:
- JAR scales
- triangle tests
- paired preference tests
- ranking tests
- hedonic scales
- sensory star profiles
- sensory evaluation sheets
You may also find our guide to Sensory Words for Food helpful when analysing your results.
