A Guide to Reducing Waste: Freezing, Dehydrating, and Composting

We’re all about being sustainable here at Farm to YoU NH. Americans waste some 60 million tons of food a year. We have a two-part blog for you with some tips and tricks on how to reduce your waste. This week we will discussing freezing and dehydrating food, as well as composting.


Freezing Foods –

When freezing foods for long term storage (6-9 months), you never want to overload your freezer, to avoid temperature variation. Another thing to avoid is under-stocking your freezer, which can be more expensive in terms of electricity cost. There are certain foods you don’t want to ever freeze, as they will undergo changes. For example, many raw vegetables and greens will lose crispness after freezing and thawing.  Many cheeses and dairy products will change textures or possibly separate, along with eggs. When storing foods, it is worthwhile to aim for air-tight seals to avoid freezer burn, and never use glass jars as the cold temperatures can cause the glass to crack.

Fruits and vegetables should always be washed beforehand, and often call for individual freezing recipes. Many vegetables will benefit from blanching, which is simply boiling for a short amount of time and cooling off in an ice bath directly after. This helps preserve color and flavor.  Fruits should be left to thaw in containers and will likely be soft. Vegetables, on the other hand, can be cooked while frozen or thawed first. It can help to freeze produce on a sheet first and then package them afterward to prevent them from sticking together during freezing.

Dehydrating/Drying Foods –

By dehydrating foods, you are essentially removing moisture from them to prevent microorganisms and bacteria from growing and spoiling the food.  To do so, one needs to heat the food to a low temperature without cooking it, and then allow the moisture to be carried away by a dry air source. This can be done in an oven or by using a food dehydrator. Many vegetables and some fruits should be blanched beforehand either by steaming or boiling (all fruits should be steamed).  Sun-drying should be done for fruits only, and requires an air temperature of at least 85˚F, low humidity and often pasteurization after drying using heat or cold to kill any bacteria before storage. Storage of dehydrated and dried foods is recommended to be in cool, dark places- optimally in some type of jar.  To reconstitute dried foods, they can be soaked in water for a certain amount of time, preferably in the refrigerator.

Composting –

Using compost is an excellent way to increase the organic matter content of your soil, resulting in more microbial activity within the root zone of your plants. Adding compost to your soil promotes healthier plants, better yields, and a natural way of making more of your fertilizer inputs.

To start, some composting systems are simply piles that are kept in the open sunlight to generate as much heat as possible within the compost pile. The rate at which composting occurs depends on a few factors – temperature and the moisture levels of the compost pile are two of the most critical.

The heat generated within a compost pile is caused by the microbial breakdown of the added organic matter. It is recommended to periodically monitor the temperature of the compost pile. Strive to keep the compost below 150 degrees F. If the pile gets hotter than this, beneficial microbes tend to die off. If the pile does exceed 150 degrees F, turning or aerating the pile will help to dissipate the heat. Decomposition occurs most rapidly when the core of the compost pile is in the range of 100 – 140 degrees F. Depending on the size of the pile, this temperature can be maintained for several weeks or months in the New England region. Maintaining these temperatures for a period of time is critical for destroying thermosensitive pathogens, fly larvae, and weed seeds. For commercial food producers, the EPA regulates that compost piles should maintain temperatures of 40 degrees C (104 degrees F) for a minimum of 5 days, with temperatures exceeding 55 degrees C (131 degrees F) for at least four hours during this period.

Starting a compost pile with a base of loam, forest litter, shredded newspaper, shredded cardboard, wood chips, dry leaves, kitchen waste, grass clippings, or livestock bedding are all good elements to get a pile started. Continue to add these elements, turning the pile to incorporate new compost as it is added. Eggshells can also be a good composting element to add.

There are some who add fish bones and other fish parts to compost pile, which makes a great fish emulsion fertilizer. However, in general, it is a good idea to leave out meats in order to avoid pest problems with animals like raccoons, dogs, and bears. Another option is to keep your compost in a container – some can be bought with a turning crank designed to turn the pile.


As you can see, freezing and dehydrating are good techniques to save certain types of food, and composting is great to reduce landfill waste as well as helping enrich your own soil. There are many ways to be more sustainable and reduce food waste. Check back next week for a short blog on canning/pickling and using what most people consider food scraps in unique ways.

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