Food Preservation: Freezing, Drying, Pickling, Canning and Curing Compared

By GoldBlock WorkshopPublished Updated

The short answer

Freezing needs constant power (0°F or lower, NCHFP) and “does not sterilize foods”; drying needs no power to store, with NCHFP’s storage times set by temperature; canning makes food shelf-stable under tested procedures; pickling and fermenting rely on a minimum level of acid (NCHFP); curing is “a meticulous process that utilizes salt and sometimes sugar, along with various seasonings” (NCHFP). Each method is covered below with the research-tested procedure from the National Center for Home Food Preservation or Utah State University Extension that governs it.

Key numbers

Which method for which job

The table shows, for each method, the foods the NCHFP and USU pages cover, whether it needs power to store, and the main risk those pages name.

Method Best for Needs power to store? Main risk if done wrong
Freezing Meat, poultry, seafood, vegetables, fruit, dairy and eggs (NCHFP pages) Yes, constantly Thawing in an outage (see Short-Term Food Supply)
Drying Fruit, vegetables, jerky (NCHFP) No Mold from reabsorbed moisture (NCHFP); jerky not brought to 160°F (NCHFP)
Canning Fruit, tomatoes, pickles (boiling water); vegetables, meat, beans (pressure) No Botulism from untested or wrong methods
Pickling and fermenting Cucumbers, cabbage, many vegetables No, if processed in a boiling-water canner; refrigerator pickles need refrigeration Botulinum growth without “a minimum, uniform level of acid” (NCHFP); salt cut in sauerkraut or fermented pickles (NCHFP caution)
Freeze-drying Cooked foods, fruit, vegetables (USU) No (once packaged) Freeze-drying “does not kill bacteria” (USU); food not fully dry
Curing and smoking Pork (bacon, ham, sausage are NCHFP’s pages) Depends on the product Procedures are product-specific; NCHFP gives each as a complete tested method

Keeping a freezer running through an outage is covered in Backup Power for Vital Loads; the outage food-safety rules are in Short-Term Food Supply.

Freezing

NCHFP: “Freezing does not sterilize foods; the extreme cold simply slows the growth of microorganisms.” Key rules:

  • NCHFP: “Freeze and store food at 0°F or lower for the best quality.” Its quality times include 8 to 12 months for fruits and vegetables, 6 to 9 months for poultry, 3 to 6 months for fish and 3 to 4 months for ground meat; after these times food “should still be safe, just lower in quality.”
  • Blanch vegetables first: blanching “slows or stops the action of enzymes which cause loss of flavor, color and texture.” Use NCHFP’s blanching times.
  • NCHFP’s packaging characteristics include “Moisture vapor resistant” and “Easy to mark”; “press to remove as much air as possible before closing.”
  • NCHFP: “Thaw meat and poultry in the refrigerator in the original wrappings”; “Meat and poultry should never be thawed in the conventional oven or at room temperature”; “Frozen meat and poultry can also be cooked without thawing.”
  • For what to do in a power outage, see Short-Term Food Supply.

Dehydrating

NCHFP’s storage rules for dried food:

  • “Pack foods into clean, dry insect-proof containers as tightly as possible without crushing”; “Pack foods in amounts that can be used all at once.” “Most dried fruits can be stored for 1 year at 60ºF, 6 months at 80ºF”; “Vegetables have about half the shelf-life of fruits.”
  • Condition dried fruit before storage: pack cooled fruit loosely in sealed jars for 7 to 10 days; “Shake the jars daily to separate the pieces and check the moisture condensation”; “If condensation develops in the jar, return the fruit to the dehydrator for more drying.”
  • “Check dried foods frequently during storage to see if they are still dry.” “Foods affected by moisture, but not spoiled, should be used immediately or redried and repackaged.” “Moldy foods should be discarded.”

USU’s moisture limit for oxygen-absorber packaging (below 10%) is in Mylar Bags and Oxygen Absorbers.

Pickling and fermenting

NCHFP: “There must be a minimum, uniform level of acid throughout the mixed product to prevent the growth of botulinum bacteria.”

  • “White distilled and cider vinegars of 5 percent acidity (50 grain) are recommended”; “Use only recipes with tested proportions of ingredients.”
  • “Do not alter vinegar, food, or water proportions in a recipe or use a vinegar with unknown acidity.”
  • “Use canning or pickling salt.” “Caution: Do not attempt to make sauerkraut or fermented pickles by cutting back on the salt required.”
  • Process shelf-stable pickles in a boiling-water canner as the tested recipe directs; see Home Canning.

Canning

Canning makes food shelf-stable without power; NCHFP advises canning “no more food than you will use within a year.” Acid foods can be processed in a boiling-water canner; low-acid foods (vegetables, meat, beans) must be pressure canned. Everything you need to know first is on Home Canning.

Home freeze-drying

Home freeze dryers remove most water from frozen food under vacuum and produce light, shelf-stable food. A 2026 Utah State University Extension fact sheet sets out the key safety points:

  • “Freeze-drying does not kill bacteria and/or other microbes. It preserves them.” USU: meat must be cooked to 160°F, before freeze-drying or after rehydration. FoodSafety.gov’s safe minimum for all poultry is 165°F (Cook to a Safe Minimum Internal Temperature).
  • Fat does not freeze like water, which slows drying, and USU warns high-fat foods can become rancid in storage.
  • Food should be “crisp, dry, or brittle, with no cold or soft spots” before packaging, in “Mylar bags with oxygen absorbers” or vacuum sealed.
  • USU: “Consuming home-frozen-dried products is not recommended beyond 5–10 years after processing.”

Curing and smoking meat and fish

NCHFP: “Curing is a meticulous process that utilizes salt and sometimes sugar, along with various seasonings.” NCHFP’s curing and smoking section gives complete tested procedures for bacon, ham and sausage; GoldBlock does not reproduce cure amounts, because each is part of one complete tested procedure.

Common questions

Which preservation method is best?

The sources do not rank them. Freezing needs constant power (NCHFP: 0°F or lower); canning and drying store without power; the table above lists what each method’s source covers.

Is freezing enough for food preparedness?

A full freezer holds a safe temperature for about 48 hours without power and a half-full one about 24 (FoodSafety.gov; see Short-Term Food Supply); canning and drying store without power.

How long does home-dried food last?

NCHFP: “Most dried fruits can be stored for 1 year at 60ºF, 6 months at 80ºF,” and “Vegetables have about half the shelf-life of fruits.”

What does the tested jerky method require?

NCHFP’s tested method brings the meat to an internal temperature of 160°F, before or after drying, because “an internal temperature of 160ºF is necessary to eliminate disease-causing bacteria such as E. coli O157:H7, if present”; drying itself is done at 140°F. The full method is on NCHFP’s jerky page.

Does freeze-drying kill bacteria?

No. USU Extension: “Freeze-drying does not kill bacteria and/or other microbes. It preserves them”; meat is cooked to 160°F before freeze-drying or after rehydration.

Where to go next

Sources