Acidified Low-Acid Foods

General Information

Non-acidic products, including most vegetables and fresh meat, can be acidified to produce acidified low-acid foods. These products are commonly called “pickles” or “pickled products”. Because there is a risk of botulism if these foods are not properly acidified and processed, there are very specific regulations that pertain to these foods. Included in this section are a number of resources addressing this category of foods.

A number of acidic foods are not considered to fall into the acidified low-acid food category. To determine if your product is an acidified low-acid food consult the following document:

Acidified Low-Acid Food Q&A (L. Harris, UC Davis Food Sci & Tech) (PDF 93 KB)

The pH and/or acidity of a food are generally used to determine processing requirements and applicability of specific regulations. You can find the  approximate ranges of pH values of common food products in tables posted online, for example:

California Regulations

Acidified low-acid foods processed in California must comply with the California Cannery Inspection & Licensing Program (CA Dept. of Public Heath)  Associated forms are from CDPH, except where noted below.  

What to Do When - A Timeline:
California Cannery License Program Timeline (CAFF, UC Davis, UCANR, WRCEFS)

Procedures and Forms

FDA (Federal) Regulations

Specific Information

Acidification of Garlic added to Oil  (FDA Safe Practices for Food Processes) Section 3.5

(Section 3.5 is copied below) From: Evaluation and Definition of Potentially Hazardous Foods, page 59 (IFT/FDA) (PDF 2.8 MB)

3.5. Garlic-in-oil1
Product: Garlic-in-oil.  The product is not held hot or cold.  The ingredients of the product are chopped fresh garlic and oil.  The product is intended to be distributed and stored at ambient temperature for extended shelf life.  Outbreaks have been associated with C. botulinum toxin in garlic-in-oil.  Microbiological hazards:  C. botulinum toxin production.

Step 1.  Processing:  Oil poured into chopped garlic in a bottle.  Although no heat is applied, vegetative pathogens are not associated with this food. Go to Table A.
Table A: pH> 4.6 and high aw (not specified).
Step 2.  Decision: Product may be a TCS food. (TCS = Time/Temperature Control for Safety)
Product Assessment: No identified product characteristic that prevents spore-forming pathogen growth.  Antimicrobial properties of garlic will prevent the growth of vegetative pathogens. 
Decision options: Challenge testing, predictive microbial model, reformulation to lower pH with acetic or phosphoric acid to < 4.6, refrigerate (TCS food), store hot (TCS food), or at ambient temperature for a limited time less than the estimated lag phase for the pathogens of concern, or not marketable.
1Flavored oil will present negligible hazard due to lack of C. botulinum survival or growth in 100% oil.

University Assistance, Information, & Training

Cornell University

North Carolina State University

From the North Carolina State University Department of Food Science:

When acidified low acid or low acid canned foods are shipped across state lines the food processor must register with the FDA in addition to the appropriate state agency. This article describes the process for filing a scheduled process with the FDA.

University of California, Davis

University of Georgia

University of Tennessee