Jam
- For other meanings of the word "jam", see Jam (disambiguation)
The proportion varies according to the type of fruit and its ripeness, but a rough starting point is equal weights of each. When the mixture reaches a temperature of 104°C, the acid and the pectin in the fruit react with the sugar, and the jam will set on cooling. However, most cooks work by trial and error, bringing the mixture to a "fast rolling boil", watching to see if the seething mass changes texture, and dropping tiny samples on a plate to see if they run. How easily a jam sets depends on the pectin content of the fruit. Some fruits, such as gooseberries, redcurrants, blackcurrants, appless and raspberries, set very well; others, such as strawberries and ripe blackberries, need to have pectin added. There are proprietary pectin products on the market, and most industrially-produced jams use them. Home jam-makers sometimes rely on adding a pectin-rich fruit to a poor setter; hence the popular old favourite blackberry and apple. Other tricks include extracting juice from redcurrants or gooseberries. Making jam at home used to be common, but the practice is declining, and the accessories, particularly the cellophane covers for jam jars, are becoming more difficult to find in some locations.
Jam is often used on bread, and also in yoghurt to sweeten it.
Jam which has been filtered to remove pulp and make it clear is called jelly. Jam which has whole pieces of fruit is called preserves, or conserves if it has nutss as well. Jam with fruit peel is called marmalade.