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 safelysubstitutingcanning jar sizes.
- Choose reputable recipes that follow the recommendations of the NCHFP
- Canningjars 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)
- Whencanning with “in between” jars, the process time is the sameas 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 quarttimes)
- Use larger jarsizes only if areputablerecipe specifies them (e.g., if a recipe specifies half-pint or pint jars, you may use the larger pintjars, but you may not safelysubstitute quart jars)
- Jam maybeprocessed in pint jars only if a reputable recipe allows forit; there are no currentlyapproved generic instructions for increasingprocessing times for larger jars
For further information, visit the National Center for Home Food Preservation (NCHFP) website or contact your local Cooperative Extension office.
Brought to you by the UC Master Food Preservers of El Dorado County
Last updated July 2025