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Survey of Home Canning Practices and Safety Issues in the U.S.

E. M. D’Sa1, E. L. Andress1, J. A. Harrison1 and M. A. Harrison2.
(1) Department of Foods & Nutrition Extension, (2) Department of Food Science & Technology, The University of Georgia, Athens, GA 30602-4356

Paper 005-04. Presented at the Institute of Food Technologists Annual Meeting, Chicago, IL, July 29, 2007.

Abstract

The use of science-based, tested processes is critical to the safety of home-canned foods. A national survey was conducted to determine consumer knowledge and practice of home canning techniques. Results indicate a critical need for education and increased awareness of safety-related concerns. The objective was to identify food safety concerns in the practice of home canning, and to compare these results with those from a previous survey (year 2001). A 2005 national telephone survey of U.S. adults was conducted, using a 42-item questionnaire about consumers’ home canning knowledge and habits. 801 complete interviews were obtained from randomly selected households across the nation, with a 95% confidence level and a 30% cooperation rate. Survey results indicate that about one in five households canned foods in 2004. The most popular sources of instructions continue to be family or friends (51.2%, earlier 48%) and cookbooks (16.7%, earlier 19%). 30.5% altered recommended canning procedures. Most commonly canned foods were vegetables (64.9%, earlier 71%) and tomato products (59.2%, earlier 60%). 9.2% used non-nutritive sweeteners in jams or jellies, with sucralose being most popular. The risky practice of open-kettle canning (hot fills only) is still practiced for fruits and tomatoes (44% of canners), vegetables (35.4%) and meats or seafood (20%). 32% (earlier 38%) of all canners had jars that did not seal properly, and 35.6% (earlier 37%) stored their home-canned foods for longer than 12 months. Education about and reinforcement of science-based food preservation resources are essential in promoting safe home-canning techniques. Failure to use recommendations can result in foodborne illness including botulism, or food spoilage. These survey results identify current critical areas of concern in U.S. consumer canning practices, and therefore provide guidelines for continued Extension-based efforts in this area.

Introduction

Home food preservation methods continue to be key interest areas for consumers wanting to use the abundance from their home gardens or local markets to have homemade specialties all year. Preserving this food safely while maximizing food quality are essential features of Extension food preservation recommendations. Home canning continues to be a popular means of preserving food at home (Andress, 2002). The importance of safe home canning practices must be emphasized. Using unsafe practices could lead to occurrence of foodborne illness (including the potentially fatal botulism), or, at the very least, food spoilage.

This national telephone survey conducted in 2005 was aimed at determining consumers’ home canning and home food preservation knowledge and practices, and identifying potential areas of food safety concern. Results obtained from this survey will also be compared with the results of a similar 2001 national telephone survey. Areas of similarity or divergence between the two surveys will be documented.

Objectives

To conduct a randomly-based national survey of U.S. households practicing home food preservation techniques on a routine basis

  • To determine consumer knowledge of safe home canning techniques.
  • To identify types and quantities of foods being canned at home.
  • To identify potential unsafe home canning practices that need to be targeted by Extension communicators.

Methods

A questionnaire was developed by researchers at the National Center for Home Food Preservation and the Survey Research Center, University of Georgia, that was translated into a 91-item (42 closed- or open-ended item canning survey) instrument. Respondents could choose more than one appropriate response for some questions. Between April 4 and June 16, 2005, a national telephone survey of adults was conducted. Telephone interviewers received training and practice in areas of survey purpose, methods, standard telephone interviewing procedures; and were supervised at all times to ensure quality control. A total of 8,848 numbers were called; and 2, 676 eligible interviewees were contacted. This yielded 801 complete interviews, of which 174 respondents canned foods at home. It is the data from this group of 174 respondents that is being analyzed in this presentation. 

In order to reduce bias in response and draw accurate inferences from the adult population, sampling procedures utilized ensured that all households had near-equal selection chances for inclusion in the sample. A 95% confidence interval and a sampling error of +/- 5% insured that estimates produced were precise and accurate. A 30% cooperation rate was obtained, and one-fifth to one-quarter of all interviews were monitored.  

Results

Who is canning?

  • 22% of respondents completing the full interview reported canning food at home during the 2004 canning season; 79% of these planned to can food the following season. These numbers are somewhat lower (27%, 91% respectively) when compared with the 2001 survey.
  • 58% (earlier 49%) of home canners are between 35-64 years of age; 27% (earlier 23%) are 65 and over, and 15% (earlier 24%) are under 35 (Figure 1).
  • 76% of respondents were female (earlier 82%) and 51% (earlier 52%) were employed during the preceding year, either year- round (77%, earlier 72%), for 26-51 weeks (15%, earlier 21%) or for less than 26 weeks (8%, 4% earlier).
  • Most home canners have at least a high school education; 28% (both surveys) have at least a 4-yr college degree (Figure 2).
  • Less than half (41%) of home canners live in 2-4 person households (Figure 3). 60% (both surveys) of these households had no individuals under the age of 18 yrs, while 15% (earlier 19%) had one under-18 yr old, and 17% (earlier 8%) had either 2 or 3 under-18s.
  • Participation in home canning does not appear to be related to income, but there was a fairly high non-response rate (48%, earlier 41%) to this question (Figure 4).
  • 84.5% (earlier 84%) of respondents were “White”, 5% (earlier 6%) African-American, less than 1% were Asian/Pacific Islander, about 1% were Native American/Alaskan Native, and 6% described themselves as multi-racial. About 5% of respondents were of Hispanic origin.


What are their sources of information?

  • Family or friends (51%), generic cookbooks (17%), directions from pressure cooker manufacturer (13%), Ball Blue Book (7.5%), directions from canning jar/lid manufacturers (7%), magazines or newspapers (4%), Extension Service (3%), the Internet (3%), community cannery instructions (0.5%) and “other” (13%).
    • In comparison, the 2001 survey results showed that the top information categories were also friends or relatives (49%) and generic cookbooks (19%), followed by directions from canning jar/lid manufacturers (10%), directions from pressure cooker manufacturers (9%), USDA publications (3%), Extension Service (2%) and “other” (25%).
  • 55% of respondents (earlier 67%) used their canning instructions “as is”, while 30.5% (earlier 29%) adapted the instructions for their personal use. 

What are they canning and how?

  • 65% canned vegetables (71% earlier), 59% canned tomatoes/tomato products (60% earlier), 52% canned fruit (47% earlier) and 65% canned pickled products.  Of those canning pickles, 20% used firming treatments, with salt water soak (22%), pickling lime (13%), ice water soak (13%), and Pickle Crisp® (9%) being the most popular firming treatments.
  • Non-nutritive sweeteners were used by some home canners in jams/jellies/preserves (9.2%), fruits (6.32%), and pickles/relishes/salsas (1.15%). Within this group, Splenda® (sucralose) was the most popular (used by 42%), followed by Sweet’n Low® (21%), Equal® (5%) & Sweet One® (5%).
  • Figure 5 represents the canning methods used by respondents who canned fruits and tomatoes, vegetables and meats/poultry/seafood. Table 1 represents a breakdown of the types and quantities of food items canned by respondents.


Table 1:  Amounts of various foods canned at home.

 

Number of respondents (n=174) who canned quantities of

1-10
Pints

11-50
Pints

51-100
Pints

>100
Pints

Fruits

10

41

11

8

Fruit products (sauce, juice purée, syrup)

8

15

5

1

Tomatoes

3

53

14

6

Tomato Sauce or Juice

5

24

6

2

Other vegetables

10

37

14

7

Soup mixtures

4

6

-

-

Cucumber pickles

4

21

3

1

Other pickled vegetables

6

11

-

2

Relishes/Chutneys

4

6

1

-

Salsas

6

20

2

-

Pickled fruits

-

3

-

-

Jams/Jellies/Preserves

16

37

10

2

Barbecue sauce

3

-

-

-

Flavored vinegars

1

1

-

-

Meat and Poultry

2

4

3

1

Fish and Seafood

3

6

1

-

Equipment Use and Management

  • Only 12% of respondents had the dial gauge on their pressure canner tested in 2004. 11% have a pressure canner without a dial gauge. Of those who had the dial gauge tested, 12.5% (2) had it tested at the Extension Service, 25% (4) at a hardware store and 6.25% (1) at a utility company. (Note: Extension agents often test pressure canner dial gauges at hardware stores.)
  • 16% of respondents reported making altitude adjustments when using their pressure canners, while 10% reported making altitude adjustments when using a boiling water canner.
  • 49% of respondents used an electric range for home canning, 24% used a gas range, 15.5% used an electric smooth-top range and 1% used sealed gas burners.

Jars and Lids

  • Approximately 64% of respondents (earlier 74%) used home canning jars with 2-piece lids, 10% used home canning jars with other lids, 2.3% used recycled jars from commercially canned foods, 7% used the older home canning jars with rubber rings, 7.5% respondents used metal cans.
  • 32% of respondents reported having jars that did not seal properly after canning. For the jars that did not seal, 20% reprocessed them, 37.5% refrigerated and consumed them quickly, about 4% froze the contents of the jars for later consumption, and 43% discarded the contents.

Food Use, Storage and Spoilage

  • 11.5% of respondents reported serving the home canned food as is, with no heating, 30% brought the food to a boil before serving, 21% boiled the food for 10 minutes or more, 24% warmed the food on a stovetop, oven or microwave, 19% used the canned food as an ingredient in other recipes, 7% steamed the food, and 3% used “other” means of preparation.
  • How long do they store the canned food? 18% reported using the home canned food within 6 months, 42.5% stored the food for 6-12 months, and 36% reported storing the food for more than 1 year.
  • What are the signs that canned food (home canned or commercially-canned) is spoiled? 86% recognized a bulging lid as a sign of spoilage, 84% mentioned “mold”, 83% mentioned “off-odor”, 78% mentioned “off-color”, 76% mentioned “leakage”, 56% mentioned “spurting liquid when container is opened” and 44% mentioned “floating fruit or vegetables” as a sign of spoilage.
  • Only 45% of respondents thought that home canned foods could be spoiled without obvious signs of spoilage, and 12% reported that their home canned food from the 2004 canning season had spoiled.

Summary and Conclusions

  • There is similarity between the results of the 2001 and 2005 surveys in some areas, but not all. The lack of consistent use of science-based home canning techniques and equipment among home canners continues to be a disturbing observation.
  • Family and friends continue to be the largest category source of instructions for home canning recommendations. Greater     use of USDA and Extension sources for recommendations would be a highly desirable shift in this observation. Mobilizing      County Extension and community efforts in this area, coupled with greater publicity given to existing USDA recommendations, is a way to change this trend.
  • Also disturbing is the continued use of unsafe home canning methods like oven canning, open-kettle canning, and the use of boiling water canning for low-acid foods. Again, education and information dissemination in this area should be emphasized.     

References

1.  Andress et al., 2002. Current Home Canning Practices in the U.S. Institute of Food Technologists Annual Meeting Presentation, Paper 46B-3.
2.  Bason, J. 2006. Materials and Methods Statement. Survey Research Center, The University of Georgia, Athens, GA.
3.  Bason, J. 2001. Materials and Methods Statement. Survey Research Center, The University of Georgia, Athens, GA



This project was partially funded through a grant from the National Integrated food Safety Initiative (Grant No. 00-51110-9762) of the Cooperative State Research, Education, and Extension Service, U.S. Department of Agriculture.

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