Bottling Fruit and Making Jam in New Zealand

Bottled peaches, plums and pears and a shelf of jam are a Kiwi pantry tradition. The safe way to do both is a boiling water bath with a tested time, rather than the overflow method many family recipes use.

What can be bottled

Fruit, jam, chutney, vinegar pickles and tomatoes with added acid. New Zealand Food Safety names low-acid foods such as asparagus, green beans, beetroot, corn and potatoes as the most common source of home-canning botulism. Those need a pressure canner, or the freezer.

Overflow or water bath?

The overflow method fills boiling fruit and syrup into hot Agee jars to the brim and seals them with no further heating. No food safety agency has tested it, and USDA lists this kind of open-kettle sealing as not recommended because it does not stop all spoilage. Processing the filled jars in boiling water for a set time is the tested alternative, and it takes about 20 to 25 minutes for most fruit.

Water bath times for fruit

From USDA, for hot-packed fruit with 1.25 cm of headspace, up to 300 m above sea level:

• Peaches, pears and plums: 20 minutes in jars up to 473 ml, 25 minutes in jars from 474 to 946 ml
• Apple slices: 20 minutes in either size
• From 301 to 900 m (Taupō, Ohakune, Tekapo, Twizel): add 5 minutes
• 1 litre jars: no tested time, so keep to 750 ml or smaller

Bring the water to a full rolling boil with the jars covered by 2.5 cm, then start timing. Lift the jars out after a 5 minute rest in the pot and leave them 12 to 24 hours before checking the seals.

Jam

Cook to about 104.5°C or the cold saucer wrinkle test, fill hot jars with 6 mm of headspace, and boil the filled jars for 5 minutes (10 minutes if you did not sterilise them). Keep the full amount of sugar unless the recipe was written for a reduced-sugar pectin. The jam guide has setting points and marmalade.

Tomatoes

Add bottled lemon juice or citric acid to every jar: 15 ml or 1/4 teaspoon up to 473 ml, double that up to 946 ml. Full method in the passata guide.

Sources we checked (October 2026): New Zealand Food Safety (MPI), Clostridium botulinum or botulism; USDA Complete Guide to Home Canning (2015) through the National Center for Home Food Preservation: Peaches, Pears, Plums, Apples (sliced), Equipment and Methods Not Recommended, General Information on Jams and Jellies, Tomato acidification.