What does candling mean?
Candling is the process of inspecting an object by shining a bright beam of light through it, most famously applied to eggs. In a darkened room, light transmitted through the shell reveals the yolk's condition, air-cell size, blood spots, cracks, or signs of embryonic development, allowing graders to assess freshness and quality without breaking the shell. The name reflects the method's origins: early practitioners held eggs up to an actual candle flame. Today commercial operations use high-intensity LED lamps that can process thousands of eggs per hour automatically. The term also extends to beekeeping, where frames of comb are examined under light, and occasionally to other translucent materials such as ceramics or gemstones where internal flaws can be detected. Candling remains standard vocabulary in poultry science and food-safety inspection, valued because it offers a non-destructive way to evaluate what cannot otherwise be seen.
nounThe practice of examining an object—typically an egg or a beekeeping frame—by shining a bright light through it in a darkened room to inspect its interior quality or contents.
- Inspecting eggs against a bright light to judge their interior quality, freshness, fertility, or shell integrity
- Examining honeycomb frames or other translucent materials by shining light through them to assess their contents
"Before the eggs were packed for sale, each one passed through candling to check for cracks and defects."
"The inspector moved quickly down the line, candling hundreds of eggs per hour to weed out any with blood spots or hairline cracks."
"Beekeepers sometimes use candling to gauge how much comb has been built out on a frame before harvesting."
Rarely pluralized; candling typically functions as an uncountable mass noun referring to the process or activity rather than countable instances.
"Multiple candlings over several days allowed the researchers to track the embryo's development."
Long before X-rays, farmers could see inside an egg just by holding it up to a candle flame in a dark room.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of candling
The word derives from "candle," which traces back through Old English to Latin candela, from the verb candere, meaning "to shine or glow white." Because the earliest inspection method involved holding an object up to a burning candle, the technique itself came to be called candling. It shares this Latin root with related words such as incandescent and candid.
Related word forms
How candling is actually used
Primarily a technical term used in agriculture, poultry science, and apiculture; rarely encountered in everyday conversation outside those industries.
Easily confused with candling
Kindling refers to small sticks used to start a fire (or the act of igniting one), while candling refers to inspecting objects with transmitted light.