Sherbet Testing

1. Sherbet Testing By Claire Knight

2. Aim of this prac • The aim of this practical activity is to determine what effect changing acid and base levels has on taste.

3. Equipment required • Icing sugar • Bicarbonate of soda • Citric Acid • Jelly crystals • 4 containers • Measuring spoons

4. The recipes tested • Recipe A (original recipe) • 4 teaspoons of icing sugar • ½ teaspoon of citric acid • ½ teaspoon of jelly crystals • ¼ teaspoon of bicarb of soda • Recipe B (more citric acid) • 4 teaspoons of icing sugar • 1 teaspoon of citric acid • ½ teaspoon of jelly crystals • ¼ teaspoon of bicarb of soda • Recipe C(more bicarb soda) • 4 teaspoons of icing sugar • ½ teaspoon of citric acid • ½ teaspoon of jelly crystals • ½ teaspoon of bicarb of soda • Recipe D (less icing sugar) • 2 teaspoons of icing sugar • ½ teaspoon of citric acid • ½ teaspoon of jelly crystals • ¼ teaspoon of bicarb of soda

5. Predict – Reasons for the recipes chosen • It is predicted that the sherbet with more citric acid than the original recipe will produce a greater chemical reaction and taste better than the recipe with more bicarb soda and the last recipe that will have less icing sugar.

6. Method • In each container, carefully measure the required ingredients. • Mix well. • To conduct taste test, use a small stick or spoon to place a small amount of the mixture into your mouth.

7. Observe - Results

8. Acids & Bases • The acids in this test were – the citric acid, food acid in the jelly crystals. • The bases in this test were – the bicarbonate of soda. There was only a small amount of bicarb soda required because it has a much higher pH level in comparison to citric acid, which is a weak acid.

9. Explanation of results • Prediction – that the sherbet with more citric acid (Recipe B) than the original recipe (Recipe A) will produce a greater chemical reaction and taste better than the recipe with more bicarb soda (Recipe C) and the last recipe that will have less icing sugar (Recipe D). • From the results, Recipe B did produce a greater chemical reaction, as it was far more fizzier than Recipe C & D. This reaction can be explained by there being more citric acid in the mixture. It was more pleasant to eat than Recipes C & D, as C had more bicarb, which produces a more bitter tasting reaction and D had less sugar, which again meant a more bitter taste.

10. Further explanation • To reproduce this test again, it would better if the tester didn’t know which each mixture was, creating a ‘blind test’. • Also another recipe could be chosen when less jelly crystals were used, as the ingredients of jelly crystals include cane sugar and food acids. • The test would be more fair if more testers were involved, as would allow for more comparison of results.