Recent U.S. Department of Agriculture research has shown that white-fleshed peaches and nectarines are lower in acid than traditional yellow-fleshed varieties, according to a news release from the University of Maine Cooperative Extension in Orono. This means white-fleshed varieties are considered a low-acid food for canning purposes, and freezing is the only recommended method of preserving.

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USDA and UMMaine Extension canning recipes using peaches are only safe when using the yellow-fleshed variety.

USDA research also found that elderberries (Sambucus spp.) and their juice are low in acid and cannot be safely used in USDA- or UMaine Extension-recommended recipes that have been tested with other berries naturally high in acid, such as blueberries or blackberries. For more information, visit

Extension educator Kathy Savoie cautions that up-to-date information about canning methods and canning equipment is essential to ensure safe home food preservation.

More information is available on the Extension food preservation website at or by calling 207-581-3188, 800-287-0274 in Maine.