Taste and Smell testing
Multipack crisps (different flavours)
Pour a bag of crisps in a bowl and label the bowl with a number (or use different coloured bowls) so you can identify the flavour. Repeat for all flavours.
Ask the scouts to taste one crisp and identify the flavour.
Do a similar thing with smell - blindfold the scouts and get them to smell various foods and identify the food.
And finally, in pairs, blindfold one and give the other one a spoon to put three ingredients on to feed to the other, who should try identifying the food. Be imaginative with the possible ingredients!
Alternative options: sample different types of dehydrated foods. How much do they weigh in dehydrated state, assess nutritional value and ease of preparation.