Freeze Drying Batch Calculator. Enter your fresh produce weight, initial moisture content, and target moisture content to calculate your freeze drying batch results. The Freeze Drying Batch Calculator shows you the expected dried weight, water removed, yield percentage, and estimated rehydration water needed — so you can plan every batch with confidence. Also try the Pickling Brine Calculator.
The calculator uses the initial moisture content and target moisture content of your produce to determine how much water will be removed during freeze drying. It then computes the expected dried weight and overall yield as a percentage of your original fresh weight. See also our calculate Recommended Pressure, Pressure in kPa & Altitude Band — Pressure Canner PSI.
Most fruits range from 75–90% moisture (e.g. strawberries ~90%, apples ~85%), while vegetables range from 70–95% (e.g. broccoli ~89%, corn ~76%). Meats typically fall between 50–70% moisture. Using accurate moisture values improves your batch planning.
For long-term shelf-stable storage, a target moisture content of 1–4% is recommended. Most commercial freeze-dried products aim for 2% or lower to prevent spoilage and maintain a 25+ year shelf life when properly packaged.
Rehydration water is approximately equal to the weight of water removed during freeze drying. To reconstitute, you add back roughly the same mass of water that was extracted. The calculator estimates this automatically based on your inputs.
Drying time depends on the food type, moisture content, tray loading, and your machine's capacity. Typical cycles range from 20–40 hours. High-moisture foods like raw meats or soups take longer, while low-moisture items like herbs can complete in 12–20 hours.
The yield (dried weight as a percentage of fresh weight) depends on the food's moisture content. For example, strawberries at 90% moisture dried to 2% yield only about 8% of their original weight — meaning 1 kg fresh yields roughly 80 g dried.
This depends on your freeze dryer model. Home freeze dryers (like those from Harvest Right) typically hold 4–7 trays at 2–3 kg fresh food per tray. The calculator divides your total fresh weight by the number of trays to estimate the load per tray.
Freeze drying is one of the best preservation methods for retaining nutrients, color, and flavor. It removes up to 98% of moisture while preserving the cellular structure of the food, retaining approximately 97% of nutritional value compared to fresh produce. You might also find our calculate Cross-Contamination Risk Risk Score useful.