Bulletin #4032, The Cost of Preserving Food in Maine
Adapted by Kathy Savoie, Associate Extension Professor and Kate McCarty, Community Education Assistant, University of Maine Cooperative Extension.
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Table of Contents
- Cost of Freezing
- Cost of Pressure Canning
- Cost of Hot Water Bath Canning
- Cost of Dehydrating
- Cost of Cold Storage
- Summary
- References
Mainers are known for being thrifty, traditional, and self-sufficient individuals. In the past several years, the demand for food preservation education has increased, with University of Maine Cooperative Extension serving as the go-to resource. There are many reasons to preserve food, either food you have grown or purchased from a farmers’ market or Community Supported Agriculture (CSA) program.
Data collected from 2009-2016 from 2,606 participants in University of Maine Cooperative Extension hands-on food preservation workshops identify the top three reasons for wanting to preserve foods as increasing year-round consumption of locally grown foods, personal satisfaction, and to preserve homegrown fruits and vegetables. Only 40% of participants identified a desire to save money on grocery bills as a reason for preserving.
Whether for taste preference, control over added ingredients, increased access to locally grown foods, or self-sufficiency, it should not always be assumed that preserving homegrown foods saves money compared to store-bought foods.
There are many ways to preserve food, such as canning, freezing, and drying. Deciding which method to use depends on the recommended method for the product, your household’s taste preferences, your household storage space, and cost.
Calculating the cost of preserving does not include the cost of food or the cost of the time used to preserve food. Since food costs vary depending on region and preferred point of purchase (i.e. grocery store, farmers’ market, garden) it would be difficult to estimate an average price per pound of food.
Time or labor was not considered in determining the cost of preserving, as some methods of food preservation take longer than others, and there are many non-economic reasons for wanting to preserve food at home. Additional costs associated with preserving are that of added ingredients, equipment, packaging for storage, and energy use.
For the purpose of this comparison, the price range for the equipment needed to preserve and store foods was determined by collecting the cost of items at large department stores, grocery stores, independent hardware stores, and farm and garden centers.
Cost of Freezing
Freezing is a simple method of food preservation and can result in high-quality preserved foods when proper processing is followed. Deciding what foods to freeze depends on several factors, such as cost of equipment, additional energy use, available freezer space, and the household’s taste preferences. Freezing is very simple, retains nutrients, and results in a versatile product, as well as one that is closest to fresh in texture. However, the price of an additional freezer can be significant.
| Item | Price Range | Average Price |
|---|---|---|
| Pint freezer containers (each) | $.45-$1.07 | $.84 |
| Quart freezer bags (each) | $.09-$.21 | $.15 |
| Plastic wrap (per sq. ft.) | $.01-$.03 | $.02 |
| Freezer paper (per sq. ft.) | $.06-$.07 | $.06 |
| Freezer (14.8 cu ft.) | $379.80-$450.49 | $410.09 |
The cost of a freezer is the greatest cost associated with using freezing as a method of food preservation. Buying a used freezer can reduce the cost, but a greater risk of malfunction or expensive repairs is also assumed. If purchasing a used freezer, be sure to purchase one with an Energy Star rating, as it is more energy efficient. The longer a freezer lasts, the less the cost per year becomes. For the purpose of this comparison, the cost of most equipment is amortized over 20 years.
A freezer is most efficient when it is full, due to the insulating properties of the contents, so it’s important to select a freezer size that is large enough to accommodate your food needs, while remaining relatively full. For the purpose of this comparison, we priced a 14.8 cubic foot chest freezer, which holds approximately 518 pounds of food, and assumed that the freezer was full.
The energy usage of your freezer will be affected by factors such as the amount of food in the freezer, temperature of the room the freezer is in, frequency of door openings, and the defrosting and maintenance of your freezer.
The factors used to determine the cost of freezing one pound of food are the energy used to heat and blanch the food (at an average of 10 minutes per pound), to freeze the food, and to maintain frozen food at 0°F for one year. The per pound cost of heating and blanching on an electric stove is determined by multiplying the energy use of the large burner (2,400 watts in an hour) by 10 minutes and then multiplying by the cost per kilowatt usage in Maine.
The formulas for kilowatt-hour use during freezing and blanching, cost of repairs of equipment, and appliance energy use come from USDA research. The cost of residential electricity use in Maine was $.06/kWh in 2017 according to the Maine Public Utilities Commission.
| Formula | Cost |
|---|---|
| 0.1 kWh/lb. to freeze 2.3 kWh/lb. to maintain 0°F 2.4 kWh/lb. x $.06/kWh in Maine | $.14 |
| Cost of pint freezer container, divided over 5 years $.94/5 yrs. | $.17 |
| Energy to heat and blanch 518 pounds of food at 10 min/lb. 2,400 watts (energy use of large burner) x .16 hours = 401 watts/1,000 = .40 kWh $.06/kWh x .40 kWh = $.02 | $.02 |
| Freezer cost, divided over years and pounds food $410.09/20 yrs./518 lb. | $.04 |
| Repairs of freezer, divided over years and pounds of food $410.09/2%/518 lb. | $.01 |
| Total cost/lb. | $.38 |
Cost of Pressure Canning
Pressure canning is an alternative to freezing vegetables, tomatoes, and other low-acid foods. Choosing to pressure can as a method of preservation depends on the cost of equipment, personal taste preferences, and the type of food you are looking to preserve.
Canning equipment is factored into the cost of pressure canning with canning jars amortized over 10 years and new lids each time. The repairs and maintenance of a pressure canner will be less if a weighted gauge canner is used rather than a dial gauge canner. A dial gauge needs to be tested annually for accuracy and replaced if it reads outside the acceptable deviation. Replacing the dial gauge will increase the cost of canning equipment over time.
University of Maine Cooperative Extension offers free dial gauge testing service. Contact UMaine Extension at 1.800.287.0274 or visit our Food Preservation website to schedule an appointment to have equipment tested.
A canning kit refers to a four to five-piece kit that contains a:
- jar lifter,
- jar funnel,
- magnetic lid lifter, and
- headspace measurer/bubble freer.
The cost of canning equipment varies widely by retailer, so price comparison can add significant savings.
| Item | Price Range | Average Price |
|---|---|---|
| Pint canning jar (each) | $.77-$.97 | $.82 |
| Pint Canning jar lid (each) | $.14-$.36 | $.24 |
| 16qt. pressure canner and rack | $69.97-$79.32 | $74.64 |
| Canning kit | $6.97-$14.43 | $12.29 |
To determine the cost of processing in a pressure canner, the energy cost to operate a large electric burner for two hours was divided by the number of pint jars in a canner, assuming that one pint jar holds roughly one pound of food.
The canning equipment, the canner, and the jars were all accounted for in the cost of canning by dividing the price of the equipment by the anticipated lifespan as well as by the yield of the canner load. The resulting figure estimates the cost to preserve and store one pound of food for a year.
| Formula | Cost |
|---|---|
| Fuel for preparing and processing (electric range large burner uses 2,400 watts per hr.) (2,400 watts x 2 hours = 4,800 watts 4,800/1,000 = 4.8 kWh $.06/kWh x 4.8 kWh = $.29 for one canner load) $.29/10 = $.03 per pint or 1 lb. of food | $.03 |
| Cost of jar divided over 10 years | $.08 |
| Cost of jar lid, each | $.24 |
| Canner cost, divided over 20 years/10 lbs. of food | $.37 |
| Cost of repairs and replacement $74.64/2%/10 lbs. of food | $.18 |
| Canning kit, divided over 5 years and total canner yield $12.29/5/10lbs | $.24 |
| Total cost/lb. | $1.14 |
Despite the cost to pressure can a pound of food being higher than that of the cost to freeze a pound of food, there are reasons one would chose to pressure can food rather than freeze it. The frequency of power outages in your area and personal taste preferences in addition to cost should be considered when choosing a method of food preservation.
Cost of Hot Water Bath Canning
Hot water bath canning is a popular method of food preservation, as it can be accomplished with household items and inexpensive equipment. This method of food preservation allows you to preserve high-acid foods, such as fruit, acidified vegetables (i.e. pickles), and acidified tomato products.
As with the equipment for pressure canning, the price of jars, two-piece lids, hot water bath canners, and canning tools can vary greatly depending on the retailer.
| Item | Price Range | Average Price |
|---|---|---|
| Pint canning jar (each) | $.77-$.97 | $.82 |
| Pint canning jar lid (each) | $.14-$.36 | $.24 |
| Hot water bath canner and rack | $19.97-$31.15 | $22.31 |
| Canning kit | $6.97-$14.43 | $12.29 |
To determine the cost of hot water bath canning, the cost of operating a large electric burner for an hour was divided by the yield of a canner, which is approximately 10 pints. Each pint jar is estimated to hold one pound of food.
| Formula | Cost |
|---|---|
| Energy to heat and process (electric range large burner uses 2,400 watts per hr.) (2,400 watts x 1 hour = 2,400 watts 2,400/1,000 = 2.4 kWh $.06/kWh x 2.4 kWh = $.14 for one canner load) $.14/10 = $.01 per pint or 1 lb. of food | $.01 |
| Cost of canning jar, divided over 10 years | $.09 |
| Cost of jar lid, every year | $.24 |
| Canner cost, divided over 20 years/10 lbs. of food | $.11 |
| Equipment repairs and replacement $ 22.31/2%/10 lbs. | $.04 |
| Canning kit, divided over 5 years/10 lbs. | $.24 |
| Total cost/lb. | $.73 |
The cost of hot water bath canning will increase if you’re preserving a product that uses added ingredients, such as sugar in jam and jelly or vinegar, salt, and spices in pickles.
While hot water bath canning is a less expensive method of preserving than pressure canning, food safety recommendations limit the products that can be preserved using the hot water bath canning method. Only high-acid foods such as jams, jellies, salsa, tomato produces, and pickles, can be preserved using a boiling water bath canner. Low-acid products such as vegetables and meat must be pressure canned or frozen.
Cost of Dehydrating
Dehydrating or drying is an attractive method of preserving, and must be accomplished using an electric dehydrator or an oven in Maine. Our high humidity levels and low nighttime temperatures prevent successful outdoor or solar dehydrating. Because dehydrators are more expensive than canners, the cost of drying can be higher than canning. If a used dehydrator is purchased, the cost per pound of dehydrating will decrease.
To dry foods, in addition to the dehydrator, there is an associated cost with packaging materials. Additional costs may be accrued by using sweeteners or anti-darkening agents when preparing foods for drying.
| Item | Price Range | Average Price |
|---|---|---|
| Quart storage bag (each) | $.09-$.21 | $.15 |
| Dehydrator | $143.04-$159.99 | $151.52 |
| Dehydrator screens | $3.55-$3.99 | $3.77 |
To determine the cost of dehydrating one pound of food, the cost of energy used to run an electric dehydrator for 8 hours (an average time) was added to the cost of equipment and packaging.
Because a dehydrator does not run at its peak wattage for the entire time it’s in operation, the cost of 70% of its energy use is accounted for. This formula comes from the dehydrator manufacturer.
A dehydrator is estimated to hold one pound of food per square foot of space. The unit selected for this comparison holds a maximum of twenty trays, so is estimated to hold 20 pounds of food.
| Formula | Cost |
|---|---|
| Energy to dehydrate Peak wattage – 1,000 watts x .7 x 1 hour = 700 watts/hour (Wh) 700Wh/1,000 kW = 0.7kWh $.06/kWh x 0.7kWh = $.04/hr. x 8 hrs. | $.32 |
| Storage Bag | $.15 |
| Dehydrator cost, divided over 20 years/20 lbs. of food $151.52/20/20 | $.37 |
| Repairs and replacement $151.52/2%/20 lbs. of food | $.15 |
| Total cost/lb. | $.99 |
The majority of the expense of dehydrating one pound of food is the cost of the equipment (a 1,000-watt dryer). A lower wattage model would reduce the cost of dehydrating, but might increase the drying time and therefore the cost of energy use.
While the cost of dehydrating one pound of food is higher than that of hot water bath canning or freezing, there are other reasons one might chose to dry foods, such as creating lightweight snacks for outdoor activities.
Cost of Cold Storage
Cold storage or root cellaring is a low-cost way to store fruit and vegetables in Maine. Apples, root vegetables (potatoes, beets, rutabagas), carrots, garlic and onions are best suited for cold storage and can last several months longer if stored in the right conditions. Additional costs for cold storage excluding the cost of food, are packing materials, such as bags, boxes, paper, or tubs, and a thermometer to meet storage conditions.
Summary
The cost of the energy use and packaging materials should certainly be considered when choosing a method of food preservation. Because the prices used in this comparison for energy and equipment are average prices, prices may be higher in some areas of the state than others. For example, the wide price range of a canning jar ($.77-$.97) may mean that canning is more expensive if the prices in your area fall towards the higher end of the range.
However, other non-economic factors such as taste preferences, storage space, recommended methods for the product you’re preserving, and price of equipment and packaging in your area may also influence your food preservation technique. Cost may be just one determining factor in your decisions about home food preservation.
| Preserving Method | Price Per Pound | Energy Cost Per Pound |
|---|---|---|
| Freezing | $.38 | $.16 |
| Hot Water Bath Canning | $.73 | $.01 |
| Drying | $.99 | $.32 |
| Pressure Canning | $1.14 | $.03 |
For more information on food preservation, such as fact sheets, how-to videos, and hands-on workshops, visit UMaine Extension Food & Health website.
References
Long, K. and Johnson, M. 2009. The Cost of Preserving and Storing Food in Alaska. Cooperative Extension Service Publication CCM-00080. University of Alaska Fairbanks.
“Maine Public Utilities Commission: Standard Offer Rates.” Maine State Government. http://www.maine.gov/mpuc/electricity/standard_offer_rates/index.html. Accessed 2/17.
Reviewed by Jim McConnon, Extension Professor and Kate Yerxa, Associate Extension Professor, University of Maine Cooperative Extension.
Adapted with permission from UAF Cooperative Extension.
Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.
© 2017
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