Freeze Dry Math

The home freeze-drying guide

Preserve the season, beautifully.

How much fits on a tray, how long it will run, what it costs in power and bags, which oxygen absorber to use, and how much water to add back. Plus prep notes for 84 foods, each written for that food.

Open the calculatorsFreeze drying times chart
A wooden harvest basket filled with assorted tomatoes, okra, shallots, and fresh herbs
A bushel of peaches (48 lb)≈ 5 batcheson a Medium
Photo: Zoe Richardson on Unsplash
91%of a strawberry is water. 1 lb dries to about 1½ oz.
13–35 his a typical batch, says Harvest Right. Pineapple can take 50.
500 ccoxygen absorber for a gallon bag of loose freeze-dried food.
0 °Fand below before drying starts. Bacteria survive it: cook meat and eggs.

New to freeze drying?

Five steps from box to pantry shelf

Start here
  1. 01ChooseWhether one pays off, and which size.
  2. 02Set upA circuit, a cool room, a raised spot.
  3. 03First batchCorn, peas or banana slices.
  4. 04StoreMylar, absorbers, 5 to 10 years.
  5. 05UseWater back in, by weight.

Calculators

All 9 calculators →

Before the batch

During and after

Storage

Money

Browse foods by type

Foods A–Z →
Fruit23 foods

Berries, stone fruit, melons and citrus. Mostly easy, mostly long, and the sugar decides how long.

Strawberries · Blueberries · Raspberries · Blackberries

Vegetables19 foods

Blanch the ones you would blanch for the freezer, skip it for peppers and onions.

Sweet corn · Green peas · Green beans · Carrots

Dairy and eggs8 foods

Pasteurized only. Fat is the limit on how long these keep.

Eggs · Milk · Yogurt · Cheese

Meat and fish10 foods

Cook it first, trim the fat, cut it small.

Ground beef · Chicken · Turkey · Ham

Meals and starches11 foods

Leftovers and batch cooking. Spread thin and break up clumps.

Cooked rice · Cooked pasta · Chili · Soups and stews

Candy and treats8 foods

Short warm cycles, big puffs, and bags sealed fast.

Skittles · Salt water taffy · Marshmallows · Jolly Ranchers and hard candy

Herbs, drinks and pantry5 foods

Small batches that pay off: herbs, coffee, starter, smoothies.

Fresh herbs · Coffee · Sourdough starter · Honey

Most-asked foods

All 84 foods →
Sliced strawberries
Strawberries22–30 h Excellent
A grid of brown chicken eggs in a molded cardboard carton
Eggs22–32 h Good
Half peeled banana fruit
Bananas20–30 h Excellent
Three ears of fresh corn on a wooden surface
Sweet corn18–26 h Excellent
Roasted chicken on white ceramic plate
Chicken20–30 h Excellent
Skittles in a row
Skittles2–6 h Good
Person pours milk into glass
Milk30–40 h Good
Two whole peaches and one halved peach with a pit on a white surface
Peaches24–34 h Good
A bowl of chili next to other bowls of food
Chili24–34 h Excellent
A bowl of yogurt with a spoon in it
Yogurt20–30 h Excellent
A pile of sliced apples sitting on top of a table
Apples18–26 h Excellent
Pineapple fruit on white table
Pineapple36–52 h Tricky

Good first foods

Easy wins

Chicken goes in cooked, never raw.

Skip these

Not worth the cycle

  • Butter AvoidFat does not dry, and it goes rancid in the bag.
  • Honey AvoidHolds its water and foams into a sticky mess.
  • Bacon AvoidToo fatty to keep for long. Bacon bits, blotted well, for months at most.

The full list and the reasons →

New guides

All 14 guides →
A pile of round, brightly colored candies in white, orange, yellow, green and black
Freeze-Dried Candy at Home: Why It Puffs, What Works, and What to Check Before SellingHow freeze-dried candy puffs, which candies work and which don't, how to run and store a batch, and the cottage food rules and costs to check before you sell any.
A bowl of frosted red berries on a pale table
Harvest Right vs Blue Alpine vs Stay Fresh: Home Freeze Dryers ComparedPrices, tray space, batch size, power, weight and warranty for every home freeze dryer from Harvest Right, Blue Alpine and Stay Fresh, from the makers' own listings, with the real pros and cons of each brand.
Two camping stoves with cook pots on a wooden table in front of green mountains
How to Rehydrate Freeze-Dried Food: Methods, Timing and SafetySoak, mist, cook it in or eat it dry: which method suits fruit, vegetables, meat, eggs, dairy and full meals, how long each takes, and how to handle rehydrated food safely.

Choosing a machine

Running batches

Storing what you make

Using it

Common questions

How long does a freeze dryer batch take?

Most of a day to two days. Harvest Right gives 13 to 35 hours for typical loads, and Utah State Extension says 20 to 40. Sugary, thick or very wet foods take longer: pineapple can run past 48 hours. Estimate a batch →

Does freeze-drying kill bacteria?

No. Bacteria go dormant and wake up again when water goes back in. Cook meat, poultry, fish and eggs before drying, and treat rehydrated food like fresh food. What not to freeze-dry →

How long does home freeze-dried food last?

Utah State Extension advises eating home batches within 5 to 10 years. The 25-year figure is a ceiling for ideal packaging and storage, not a home-batch promise. The 25-year claim, checked →

What size oxygen absorber do I need?

For a gallon mylar bag of loose pieces, about 500 cc. Dense food like rice or powder needs less, and airy food like puffed candy needs more. Size absorbers for any bag →

Is a home freeze dryer worth the money?

It depends on what you would otherwise buy. Regular batches of cheap or home-grown food usually pay the machine back in a few years; occasional novelty batches rarely do. Work out your payback →

Can I sell freeze-dried candy from home?

It depends on your state’s cottage food law, and the packaging rules matter. Ohio, for example, allows it only in an airtight package without an oxygen absorber. Candy guide and selling rules →

What this site is

Freeze Dry Math is a set of calculators and food notes for people who own, or are thinking about buying, a home freeze dryer. Machine figures come from the makers’ published specs. Water content comes from USDA FoodData Central. Food safety advice follows university extension services, which in 2026 published the most careful guidance yet on what home freeze-drying can and can’t do.

We are not affiliated with Harvest Right or any manufacturer, and we say plainly when a number is a rule of thumb rather than a measurement. More about us.