Lemons, as with all citrus, have a requirement for texture.  For the US No. 1 Grade, lemons must have at least a fairly smooth texture.  Texture refers to smoothness or roughness of the skin.  The USDA states, “Coarse pebbling is an indication of good keeping quality and is not objectionable.”  Although I am not completely sold on the “good keeping quality” idea, as I’ve never seen a study researching the storage ability of  pebbly citrus over smooth citrus, I do agree that coarse pebbling is not objectionable.

So what is a defect, if you encounter some lemons with rough texture?  The US Grade Standards for Lemons state, “Fairly Smooth means that the appearance of the lemon is not materially affected by protrusions or lumpiness of the skin or by grooves or furrows.”

As shown above, if you encounter rough texture depicted in each of these images, these you would be considered as defects, called “rough texture.”  But remember, if you are inspecting lemons bought as “Choice”, these are US No. 2 lemons.  Choice lemons allow a rougher texture, scored as a defect when the skin is badly folded, badly ridged, or very decidedly lumpy.  (The lemon in the top image would not meet the requirement of the US No. 1 or US No. 2 Grade, while the lemon in the bottom image would not meet the requirement of the US No. 1 Grade, but it would meet the requirement of US No. 2 Grade.)

And remember, texture is a quality issue.  Meaning the texture, or roughness will not progress or become worse.