Too rapid heating means the bursting of skins or poor keeping during storing. It is a common fault to bring bottled fruits to the boil (when sterilizing) but apart from wasting heat (which costs money) the fruits are being spoiled in flavour, colour and appearance. The use of a thermometer (2s.) is certainly advisable: one cannot judge simmering point correctly without. If the bottles break at the bottom during heating, it is due to the fact that no false bottom is in use; if they break at the shoulder it is because the water level is not high enough, or because during the boiling they knock against one another (often the result of using an uneven false bottom).
If a bottle bursts during sterilizing, the cap was probably screwed right down instead of leaving a half-turn unscrewed.
Wood is the safest material to store the hot bottles upon when they are taken from the sterilizer.
If one hears a hissing noise coming from one of the bottles when it is cooling, the cap has not been screwed down tight enough or it may be that there is a tiny chip in the glass cap or that the rubber band has lost its elasticity.
Green vegetables will turn an unattractive buff, red fruits a brown, and green fruits a pale fawn if stored in
A right place. If a dark cupboard is not available, store on a cool dry shelf and either cover the bottles with some dark material or wrap each round with brown paper.
If the bottles burst during storing, it is probable that the screw bands have been left on, and the product has gone bad and generated a gas which has caused th? Breakage. Should mould growths appear on the top, it is due to too rapid he.iting at the outset of sterilizing.