How Walnuts Are Harvested and Processed

Pro tips

• Mechanical tree shaking is the industry standard for efficient harvest; timing is critical to catch nuts at peak maturity when they naturally release from branches.
• Proper drying reduces moisture to 5–7% to prevent mold, maintain freshness, and extend shelf life during storage.
• Cleaning equipment removes hull fragments and separates walnuts by size and quality; damaged nuts are culled before packaging.
• Storage in cool, dry conditions preserves walnut flavor and prevents rancidity; vacuum sealing extends freshness significantly.

Equipment

mechanical tree shaker · conveyor system · cleaning and hulling equipment · drying bins or tunnels · sorting and grading machinery

When are California walnuts harvested?

Walnut harvest typically occurs in the fall, usually September through November, when nuts naturally drop or are mechanically shaken from trees.

How long does it take to dry walnuts after harvest?

Walnuts are usually dried for 7–10 days to reach the proper moisture content before cleaning, sorting, and packaging.

What equipment is used to shake walnuts from trees?

Mechanical tree shakers vibrate the trunk to dislodge mature walnuts, which then fall to the ground for collection.

Why is cleaning important in walnut processing?

Cleaning removes hulls, dirt, debris, and damaged nuts to ensure quality, food safety, and shelf stability.

Can you eat walnuts straight after harvest?

No; freshly harvested walnuts must be dried to reduce moisture content before they are safe and palatable to eat.