The in bottle pasteurisation method:
- The purpose of pasteurisation is to destroy organisms that will spoil the product – primarily yeasts that will cause fermentation. The in bottle pasteurisation method is the most popular method of pasteurisation for the small to medium scale apple juice producers.
- The pH (an indication of acidity) of your juice should be checked prior to pasteurisation to ensure that it is 3.5 or lower.
- Bottles are filled with cold apple juice, capped or left uncapped, and then immersed in a hot water bath.
- The product temperature is raised to 70°C temperature and held that temperature for 20 minutes, before the bottles are removed and capped if necessary.
- Bottles are inverted to bring the hot juice into contact with the inside of the cap and then laid on their sides to cool.
- Once cool the bottles can be stood upright or left on their sides.
Apple juice which has been pasteurised correctly using the in bottle method can have a shelf life (in glass bottles) of up to 2 years. NB The pasteurisation temperature and shelf life range above are a guide only.
We strongly recommend that you seek qualified independent advice to determine the temperature suitable for pasteurising your particular product and for advice on shelf-life. For quality control, records should be kept of each batch pasteurised - see the Digital Data Logger, which includes software.
Bottle & cap parameters:
- Bottles need to be able to resist thermal shock i.e. to withstand immersion in water of 70 °C from a starting temperature of below 10°C
- Bottles need to have sufficient capacity i.e. for expansion when the juice is heated
- The caps must have seals suitable for use with juice at a temperature in excess of 70 °C