Adjustments to recipe canning jar sizes is possible, within guidelines 

Is it possible to make changes to recommended canning jar sizes when canning your favorite recipes? In the case of canning with smaller jars, the answer is yes, you may safely size down and use a smaller jar. However, larger jar sizes may only be substituted if a recipe specifically allows for it. Follow these guidelines for safely substituting canning jar sizes.

• Choose reputable recipes that follow the recommendations of the NCHFP
• Canning jars may safely be sized down; process smaller jars for the same amount of time as for the next largest size jar (e.g., process 4-oz jars for the same amount of time as for 8-oz jars)
• When canning with “in between” jars, the process time is the same as for the next largest allowable size jar (e.g., process 4-oz jars for half-pint times; 12-oz jars for pint times; and 24-oz jars for quart times)
• Use larger jar sizes only if a reputable recipe specifies them (e.g., if a recipe specifies half-pint or pint jars, you may use the larger pint jars, but you may not safely substitute quart jars)
• Jam may be processed in pint jars only if a reputable recipe allows forit; there are no currently approved generic instructions for increasing processing times for larger jars

For further information, visit the National Center for Home Food Preservation (NCHFP) website or contact your local Cooperative Extension office.

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Last updated July 2025