Pectin test,the infallible method and other foody science.

After stewing your fruit for jam,jelly,marmalade etc and before adding any sugar place three tablespoons of methylated spirit in an old glass,add one tablespoon of the juice from your fruit ,wait one minute and then take a look,one firm gelatinous blob in the bottom shows you have a very high pectin content,such as you get from apples, lemons, blackcurrants or quince,two or three not quite so gelatinous blobs is a medium content,and runny fruit juice in there means either boil it up a lot more or add something to it with more pectin.Make sure to throw away the contents of your testing glass,not only is it flammable it is also extremely toxic.

Why do white fleshed quince turn that lovely lush colour anywhere from amber to red when cooked ? for the same reason autumn is full of rich ambers and reds,the colour of autumn leaves is down to production of chemicals called anthocyanins,produced in a deciduous trees leaves once chlorophyll production halts for the winter,when you cook and even more when you cook them with sugar the colourless phenolic compounds in quince turn into anthocyanins.Some wild and crab apples contain the same chemicals although not to the same degree as quince.
Did you know that in Tudor times quince paste was cut into squares and wrapped in edible gold foil in the houses of the nobility,it was also flavoured with what at the time were exotic spices from the Arab world such as rosewater,testicle juice musk or whale pukeambergris.

The quince has gathered every pleasing taste,
Thereby the queen of fruits she has been crowned.
Her taste is wine, a waft of musk her scent.
Her hue is gold, her shape, like the moon, round.”
—From The Arabian Nights,  p 130.