When fruits squash down it is due to the using of over-ripe fruit or to overheating, and if they go bad after some time in store, the reason is that heating was too rapid or insufficient. A tiny leak through a minute flaw in the cap will cause a similar trouble.
The using of decayed, diseased, dirty, over-ripe, bad or stale fruits or vegetables, may result in the contents going bad in about three months time. If the fruit rises in the liquid it was too loosely packed, and if the result is a pulp, severe overheating is the cause.
The skins will slit if heating is too great or if the fruit is too ripe, and browning at the top is due to insufficient covering liquid being used in the bottles.
It is natural for some fruits, such as strawberries and gooseberries, and some raspberries, to lose colour, but this cannot be avoided, and cochineal, carmine and apple green can safely be used as artificial colouring. If the fruit rises in syrup it is generally due to loose packing, although with a few varieties it is difficult to prevent. It can be made to assume a more attractive position by placing the bottle upside down in the store. If black currants set into a jelly it is due to over-cooking.
Now with vegetables – if they do not keep – it may be due to several faults – under-heating, allowing the water to go off the boil, or the use of an incorrect covering solution. If they become cloudy, especially peas, it is because they are packed too tightly.
If tomatoes burst, heating may have been too quick, although this trouble can be minimized by pricking the skins. Dirt on vegetables is direotly responsible for poor keeping, and washing, no matter how prolonged, has always a beneficial effect from the bottling point of view.