Know What the Batch Yields Before It Shrinks

Dried weight is the number that governs everything

Fresh fruit is mostly water, and drying removes precisely that. Apricots at a fifteen percent dry-down turn four kilos into six hundred grams. Apples at twelve turn the same four into slightly under five hundred. The fresh weight flatters; the dried figure tells the truth.

Every downstream plan hangs on that dried figure. Jar count, storage space, and the portion arithmetic of eating it all hang on it. A kitchen that plans four kilos of apples expects a fruit bowl's worth and receives a small bag.

The dry-down percentages are habits, not laws. Slice thickness moves them: thin apple rings finish lighter and crispier than thick wedges at the same timer. Ripeness shifts them too, because sugar holds and water hides. Use the crop band, then trust your own machine's history.

Conditioning is the step that keeps the number honest. Sealed jars equalise remaining moisture over a few days. A batch that feels dry on tray five can still hide water in the thickest piece. Shake daily, watch for fogging, and only then call the weight finished.

• Dried weight equals fresh weight times the crop's dry-down share.
• Plan jars and shelves on the dried figure, never the fresh one.
• Condition in sealed jars for a few days before trusting the batch.

Tray maths: loads, single layers, and the stacked-tray lie

The machine's capacity is trays times the load each tray carries properly. A single layer of sliced apple is roughly half a kilo. Five trays therefore run at about two and a half kilos per load, and four kilos of fruit is two loads, not one heroic afternoon.

The stacked-tray lie is the most common dehydrator mistake. Heaped trays block the air path, the centre pieces stay leathery while the edges crisp, and a twelve-hour run becomes two days of checking. The calculator assumes honest loading because dishonest loading simply doubles everything.

Load per tray varies with the crop's shape, and that is the input's real judgement call. Leafy herbs hold air and weigh little per tray. Dense squash slices sit flat and stack their mass. Cherry tomatoes on skewers land somewhere in between, and your own racks teach the figure fastest.

Where the loads figure comes out unwelcome, change the system rather than the habit. More trays, a second machine borrowed for the season, or a bigger fresh-weight plan spread across weeks all beat overloaded racks. The number is a scheduling problem, and scheduling problems have scheduling answers.

Jars and shelf space: filling the pantry in whole units

Six hundred grams of dried apricot fills two 250-gram jars outright, and a third jar gets a useful part-fill. The planner counts full jars exactly and shows the remainder, because pantry reality is whole units with one odd lid going spare.

Jar size is a habit decision disguised as a specification. Small jars open and finish quickly, which suits a household that eats trail mix slowly. Large jars suit a kitchen that bakes through a batch of apples in a fortnight. Match the unit to the rate of use, not to the sale at the shop.

Air is the shelf-life tax on every jar. Vacuum seals and oxygen absorbers stretch dried fruit from months toward a year or more. A reused biscuit tin, by contrast, is a few-weeks plan in a humid kitchen. The jar figure from this planner is the demand; the sealing method sets how long that demand can wait.

Label the jars with the weight the calculator predicted, not a vague name. Six hundred grams of apricot halves is a known quantity in February; a jar marked just fruit is an archaeology project. The number survives the pantry better than the memory does.

Eating it down: portions and the winter arithmetic

Dried food concentrates as it shrinks. A handful of apricots is three pieces of fresh fruit and roughly the same sugar. Portions are therefore a planning matter rather than an appetite matter. Twenty to forty grams is a sensible serving size, and the jar count then divides into weeks of eating.

Two full jars of dried fruit at a weekly handful each is about twelve weeks of kitchen use. That winter figure is the difference between a batch that gets eaten and a batch that gets found three years later at the back of a shelf.

Rehydration ratios bring the batch back into cooking. Dried weight roughly returns to fresh with a soak, so five hundred grams of apples rebuilds toward a plausible pie filling. Soups and stews take vegetables directly, no soak required, and the dried figure converts to a pot of food at cooking weight.

Where a batch overshoots the household's honest eating rate, the plan should shrink the next fresh weight rather than glorify the freezerless shelf. The same maths runs in reverse: jars wanted per season, divided by dry-down, times jar size, gives the fresh weight worth slicing.

Assumptions, limits, and what the planner cannot see

The model is arithmetic on weight, not on your machine. Humidity, airflow and tray position change drying time but not the shrinkage maths. Time is left to the manual and your own tests, because it varies so wildly. The planner counts what comes out, not how long the middle takes.

Dry-down percentages are bands, and a crop between bands belongs to the cook's judgement. Tomatoes at twelve percent and tomatoes at twenty represent different products, sun-style versus leathery, and both are correct on their own terms. Enter what you are actually aiming for.

Safety sits outside the arithmetic. Herbs and fruit dry shelf-stable with honest water removal. Low-acid vegetables and anything near meat territory demand different handling, temperature knowledge, and sometimes a pressure canner this calculator has never heard of. Drying is not a universal preserve.

Finally, the planner sizes one batch at a time. A glut that outruns the machine's loads is a scheduling problem with a preserving answer. The harvest preservation planner here splits the same glut across freezer, shelf and jar, which is the bigger arithmetic the dehydrator serves.