UACES Facebook The Science Behind Food Preservation Methods: Hot vs. Raw Pack Peaches
skip to main content

At Home with UAEX

Learn from the best Extension Educators on being at home with UAEX!

The Science Behind Food Preservation Methods: Hot vs. Raw Pack Peaches


by Original Author: Megan Wells, Pulaski County | Adapted for Blog: Torrie Smith, Van Buren County

Many fresh foods contain from 10 percent to more than 30 percent air. How long canned food retains high quality depends on how much air is removed from food before jars are sealed. Raw-packing is the practice of filling jars tightly with freshly prepared, but unheated food. 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.

CAUTION: Do not use this process to can white-flesh peaches. There is evidence that some varieties of white-flesh peaches are higher in pH (i.e., lower in acid) than traditional yellow varieties. The natural pH of some white peaches can exceed 4.6, making them a low-acid food for canning purposes. At this time there is no low-acid pressure process available for white-flesh peaches nor a researched acidification procedure for safe boiling water canning.Freezingis the recommended method of preserving white-flesh peaches.

Quantity:An average of 17½ pounds is needed per canner load of 7 quarts; an average of 11 pounds is needed per canner load of 9 pints. A bushel weighs 48 pounds and yields 16 to 24 quarts – an average of 2½ pounds per quart.

Quality:Choose ripe, mature yellow-flesh peaches of ideal quality for eating fresh or cooking.

Please readUsing Pressure CannersandUsing Boiling Water Cannersbefore beginning. If this is your first time canning, it is recommended that you readPrinciples of Home Canning.

Procedure:Dip fruit in boiling water for 30 to 60 seconds until skins loosen. Dip quickly in cold water and slip off skins. Cut in half, remove pits and slice if desired. To prevent darkening, keep peeled fruit inascorbic acid solution. Prepare and boil a very light, light, or mediumsyrupor pack peaches in water, apple juice, or white grape juice. Raw packs make poor quality peaches.

Hot pack– In a large saucepan place drained fruit in syrup, water, or juice and bring to boil. Fill jars with hot fruit and cooking liquid, leaving ½-inch headspace. Place halves in layers, cut side down.

Raw pack– Fill jars with raw fruit, cut side down, and add hot water, juice, or syrup, leaving ½-inch headspace.

Adjust lids and process.

Processing directions for canning peaches in a boiling-water canner are given inTable 1.

Processing directions for canning peaches in a dial- or weighted-gauge canner are given inTable 2andTable 3.

 

Table 1. Recommended process time for Peaches, halved or sliced in a boiling-water canner. 

Style of Pack and Jar Size Process Time at 0 - 1000 ft Process Time at 1,001 - 3,000 ft Process Time at 3,001 - 6,000 ft Process Time above 6,000 ft 
Hot, Pints 20 min 25 min 30 min 35 min
Hot, Quarts 25 min 30 min 35 min 40 min
Raw, Pints 25 min 30 min 35 min 40 min
Raw, Quarts  30 min 35 min 40 min 45 min

 

Table 2. Process Times for Peaches (Halved or Sliced) in a Dial-Gauge Pressure Canner. 

Style of Pack Jar Size Process Time (Min) PSI at Altitudes of 0 - 2,000 ft PSI at Altitudes of 2,001 - 4,000 ft PSI at Altitudes of 4,001 - 6,000 ft PSI at Altitudes of 6,001 - 8,000 ft
Hot and
Raw		 Pints or
Quarts		 10 6 7 8

9

 

 

Table 3. Process Times for Peaches (Halved or Sliced) in a Weighted-Gauge Pressure Canner 

Style of Pack Jar Size Process Time (Min) PSI at Altitudes of 0 - 1,000 ft PSI at Altitudes Above 1,000 ft
Hot and
Raw		 Pints or
Quarts		 10 5 10

 

 

For more information, check out the website for the National Center for Home Food Preservation or contact your Family and Consumer Sciences at your County Extension Office. 

Top