The math
Everything in a food that is not water stays behind after freeze-drying. So the dried weight is the fresh weight times the solids share, plus a little moisture the process leaves in. Well-finished home freeze-dried food usually holds 2–4% moisture; we use 3%.
Dried weight = fresh weight × (1 − water%) ÷ 0.97
For 10 lb of strawberries at 91% water: 10 × 0.09 ÷ 0.97 = 0.93 lb, about 15 oz.
How much is left, food by food
| Food | Water | 1 lb fresh becomes | 10 lb fresh becomes |
|---|---|---|---|
| Watermelon | 91% | 1.5 oz | 0.93 lb |
| Strawberries | 91% | 1.5 oz | 0.93 lb |
| Apples | 86% | 2.3 oz | 1.44 lb |
| Bananas | 75% | 4.1 oz | 2.58 lb |
| Sweet corn | 76% | 4.0 oz | 2.47 lb |
| Eggs | 76% | 4.0 oz | 2.47 lb |
| Chicken | 65% | 5.8 oz | 3.61 lb |
| Cooked rice | 68% | 5.3 oz | 3.30 lb |
| Cheese | 37% | 10.4 oz | 6.49 lb |
Water figures are rounded from USDA FoodData Central. Real produce varies with ripeness and variety by a few percent, which is why the dryness check compares against this number with some tolerance.
Planning bags by volume
A dehydrator shrinks food. A freeze dryer mostly does not: the ice leaves behind a sponge of the original shape. That means a full Medium batch of sliced fruit can fill three or four gallon bags while weighing about a pound. Bag counts depend on how the pieces pack, so the planner uses a fresh-weight-per-bag figure you can tune. Liquids and purees are the exception: they dry into sheets that you break or grind, and powder packs much tighter.
Write the fresh weight on each bag. When you rehydrate, add back the difference between the fresh and dried weight and you have the original food again.
Read next
- Making Your Own Freeze-Dried Backpacking Meals: Which home meals freeze-dry and rehydrate well on the trail, how to portion and pack them, how much water each needs, and the fat and safety limits to respect.
- Freeze Dryer vs Dehydrator: Which One Makes Sense for You: Cost, texture, shelf life, nutrition, speed and which foods each handles best, with the break-even math on whether a $2,000+ freeze dryer is worth it over a $100 dehydrator.
- Mylar Bags and Oxygen Absorbers for Freeze-Dried Food: Which bag thickness to buy, how many cc of oxygen absorber each bag size needs, how to seal properly, and the packing mistakes that ruin a batch months later.
Questions people ask
How much does 1 pound of strawberries weigh freeze-dried?
Strawberries are about 91% water, so 1 lb fresh leaves roughly 0.09 lb of solids. With the 2–4% moisture that stays in well-dried food, that is about 1.5 oz.
Why do my bags fill up so fast?
Freeze-drying removes water without shrinking the food much, unlike a dehydrator. The pieces keep most of their size, so a gallon bag fills by volume while it still weighs only ounces.
Why use the fresh weight and not the dried weight?
You can measure fresh weight easily and it tells you exactly how much water to add back later. Write it on the bag: it turns rehydration into simple subtraction.
What about foods not on the list?
Choose “Something else” and enter a water percentage. USDA FoodData Central lists water content for thousands of foods; look in the nutrient table for “Water”.
Sources
- USDA FoodData Central (SR Legacy water content)
- Utah State University Extension: Can I Freeze-Dry That? (water activity and shelf life)
- Iowa State University Extension AnswerLine: Preserving by home freeze drying
Figures checked 2026-10-21. How we check them. Spot something off for your machine? Tell us.