Looking for Floating Fruit in Home Canning: What causes fruit, like peaches, to float in jar of canned fruit or jams? in 2020? Scroll down this page and follow the links. And if you bring home some fruit or vegetables and want to can, freeze, make jam, salsa or pickles, see this page for simple, reliable, illustrated canning, freezing or preserving directions. There are plenty of other related resources, click on the resources dropdown above.
There are a variety of reasons why fruit floats:
It can also be due to the canning method - raw v. hot packing.
Raw-packing is the practice of filling jars tightly with freshly prepared, but unheated food. Such foods, especially fruit, will float in the jars. The entrapped air in and around the food may cause floating and discoloration within 2 to 3 months of storage. Raw-packing is more suitable for vegetables processed in a pressure canner.
Hot-packing is the practice of heating freshly prepared food to boiling, simmering it 2 to 5 minutes, and promptly filling jars loosely with the boiled food. Whether food has been hot-packed or raw-packed, the juice, syrup, or water to be added to the foods should also be heated to boiling before adding it to the jars. This practice helps to remove air from food tissues, shrinks food, helps keep the food from floating in the jars, increases vacuum in sealed jars, and improves shelf life. Preshrinking food permits filling more food into each jar. Hot-packing is the best way to remove air and is the preferred pack style for foods processed in a boiling-water canner. At first, the color of hot-packed foods may appear no better than that of raw-packed foods, but within a short storage period, both color and flavor of hot-packed foods will be superior.
Note that any portions of fruit that are above the liquid in the jar will
darken over time (surface oxidation), but these portions are still safe.
Because they are visually unappealing, some people just cut the dark
sections off and discard them.