The traditional flaming Christmas pudding dates back to 1670 in England and was derived from an earlier form of (not very appetising-sounding) stiffened plum porridge. One of the normal ingredients of Christmas pudding and of many other dishes served in the winter months is nuts. However, many people are allergic to nuts and can have severe reactions from simply touching nut oil. This effect is called anaphylaxis, and can be caused by bee and wasp stings, latex and some medicines as well as nuts. Fortunately, anaphylaxis can be treated effectively with adrenaline. But it’s not just people who have problems with some Christmas food though. For instance, sweet almonds, the basic ingredient of marzipan, are poisonous to dogs, foxes, and turkeys – so no feeding Christmas cake under the table to your dogs (or to foxes for turkeys for that matter!).

	Sensitive vegetables!
	Love them or hate them, brussel sprouts can loom large at Christmas! If you one of those who’d like to reduce the number of sprouts which are going to need eating, try this experiment, which shows just how sensitive vegetables can be!
	You will need:
	Brussel Sprout leaves Hot water Clear vinegar Bicarbonate of soda Lemon juice
	Step 1
	Put the sprout leaves in a bowl and pour the hot water over them, stir and leave for a few minutes. This should give you a yellowy-green liquid. Drain the liquid from the leaves and put it into a beaker.
	Step 2
	Now try putting some sprout juice into different liquids to see what happens. Try the lemon juice first. Pour a little lemon juice into a beaker. Pour some of the green sprout juice in and give it a shake. What do you think will happen?
	Step 3
	The liquid changes colour! Lemon juice is an acid and acids turn the sprout juice a different colour. To see the colour change better, put your sprout juice in a clear glass dish on top of a piece of white paper.
	Step 4
	Next, try adding a little to a solution of bicarbonate of soda and water. Give the mixture a shake again and see what happens.
	Step 5
	The liquid changes colour again! Bicarbonate of soda is alkaline and when you mix it with water it turns the sprout juice a different colour.
	Step 6
	Now add some clear vinegar. Can you predict what happens? Here’s a hint – vinegar is an acid…
	Step 7
	Yes – the liquid changes colour again! Experiment with different things and find out which are acidic and which are alkaline. Does the colour depend on how much sprout juice you use. Do other vegetables produce indicator liquid?
	Why does this happen?
	Sprout juice is sensitive to whether something is an acid or the opposite, an alkali. Other vegetables are similarly sensitive, and you may get an even stronger reaction if you use red cabbage leaves. If you add acid to red cabbage juice, it goes red, add an alkali and it goes blue. It might sound strange, but you’ll find different reactions in different parts of the UK. In East Anglia for example, the water is strongly alkaline and in Cornwall water is acidic. Your local water will affect the reactions you get for this experiment.