Post Harvest Handling for a Small Farm

Post harvest handling starts when the knife hits the stem. The harvest is not done at the tote. Field heat is still in the crop. That heat is where grade leaves, before the cooler ever sees the load.

Field heat is the loss

A leaf pulled at midday is a hot leaf. It keeps respiring. Respiration is heat, and heat is wilt, yellowing, and a shorter hold. The pack-shed question is simple. How much heat walked in with this pick, and can you knock it down before the greens go soft.

Hydrocooling is the first pass. The window unit is not the first pass. A CoolBot on a walk-in is sized to finish a pull-down in four hours after the crop is already washed and wet. Four hours on a dry, hot tote is four hours of respiration you already lost.

Pick earlier if the afternoon temperature is the thing walking into the shed. Shade the totes between the bed and the wash. A tote in the sun is a second field.

Wash water

Wash water should be colder than the pulp. Warm water on a cold crop drives bacteria and field heat in through the stem scar and the pores. Cold water on a hot crop pulls the heat out. That is the hydrocool. Do not wash a hot tomato, pepper, cucumber, or basil in a cold bath and then park it in the cold-wet box. Those crops do not belong at the greens set point. The pack-shed splits them on purpose.

Greens, herbs that tolerate cold, and brassicas go to the cold wet zone after the wash. Fruiting crops and basil go to the cool humid zone. Mixing them to save a tote costs the fruit, not the lettuce.

Change dirty water. Soil in the tank is a shared bath for every head you dunk after it. One muddy tote inoculates the rest of the pick.

Drain the totes. A washed crop sitting in its own water reheats and rots from the bottom. The wash only counts if the water leaves.

What cures first

Onions and winter squash do not go into the cold box off the field. They cure. The pack-shed keeps a curing hold separate from the cold zones. Curing is warm air and time, so the necks dry and the skins set. A cold wet box on a fresh onion is rot in the neck. A cold wet box on a fresh squash is a soft spot you will find in December.

Cure them, then store them. Do not “cool them down quick” because the cooler has room. Room is not a reason.

Potatoes and garlic follow the same split if you are holding them. They are not a greens tote. If the crop needs a skin to set, it is a curing crop until that skin is set.

Where grade actually leaves

Grade leaves in four places. In the field, if you cut past the holding window. Between the bed and the shed, if the tote sits in the sun. In the wash tank, if the water is warm or dirty. In the box, if a curing crop or a chill-sensitive crop shares a wall with the greens.

The cooler does not fix any of those. It holds the grade you still have. A wilted leaf at 34 degrees is still a wilted leaf.