Fresh Lemons

A lemon lot is fruit sized and packed by count, specified on rind colour, rind texture and thickness, firmness, juice content, and freedom from blemish and decay. Harvest is driven by size and rind condition rather than by any sweetening endpoint, so a grower picks when the fruit reaches a marketable size and the rind is in the state the market wants — which for much of the trade means picking green and letting colour develop afterwards.

Two commercial forms flow from this. Green-picked fruit is stored and degreened or held to develop yellow colour, entering the market on a schedule. Tree-ripe yellow fruit is picked as it colours. Both are the same commodity at different points, and because the fruit tolerates storage well, the choice is genuinely a trading decision rather than a biological constraint.

Lemons store better than oranges, mandarins, or grapefruit, and the trade exploits this heavily. Green-picked fruit can be held in cool storage for an extended period during which the rind gradually develops its yellow colour and the fruit is released to market as demand requires. This holding period is sometimes called curing, and it turns a seasonal crop into a nearly continuous supply — a scheduling capacity that few fresh fruits possess.

Where market colour is needed faster than it develops naturally, degreening with ethylene is used to break down the green pigment in the rind. This is a cosmetic treatment on a non-climacteric fruit: it changes the peel, not the flesh, and a degreened lemon is not riper than it was. Regulated post-harvest fungicide and wax treatments accompany storage, and permitted materials and residues differ by destination market.

The lemon rind holds oil in glands just below its surface, and that oil is both a valuable co-product recovered during juice processing and a hazard during handling. When turgid fruit is squeezed or knocked, oil glands rupture and the released oil damages surrounding rind tissue, producing the sunken, discoloured spotting known as oleocellosis. It is the reason the citrus trade avoids handling fruit while it is wet or fully turgid — early in the morning, or after rain or irrigation.

Chilling sensitivity compounds the handling picture. Lemons are more cold-sensitive than oranges, and holding them below tolerance produces rind pitting, membrane staining, and red blotch that appear after the fruit is moved to warmer conditions — meaning the damage surfaces at the buyer's end, not in the store.

Grading covers size and count, rind colour and texture, rind thickness, shape, firmness, juice content, and freedom from defects. Rind thickness matters commercially in both directions: thick, coarse rind reduces juice yield, while very thin rind gives less protection in handling. Juice content is the maturity criterion in most jurisdictional standards.

• Green and blue mould decay through rind wounds
• Chilling injury — rind pitting, membrane staining, and red blotch
• Oleocellosis from handling turgid or wet fruit
• Stem-end rind breakdown in stored fruit
• Excessively thick or coarse rind reducing juice yield
• Shrivel and softening in fruit held past its storage life

Lemons are sold fresh for culinary use, and processed for juice, concentrate, and rind oil. Processing is unusually integrated here: pressing a lemon yields juice, essential oil recovered from the rind, and peel residue, and the oil is a high-value stream in its own right for flavour, fragrance, and cleaning products. Peel residue and pulp from lemon processing feed into pectin manufacture and livestock feed, as they do for oranges.

• Food — fresh fruit for culinary and garnish use
• Beverage — juice and concentrate for drinks and acidification
• Industrial — rind essential oil for flavour, fragrance, and cleaning products