What does 'bloom' refer to on a grape's skin?

The term 'bloom' refers to a natural waxy coating that forms on the skin of grapes. This protective layer serves several important functions. It helps to reduce moisture loss and protects the grapes from various environmental stressors, including pathogens and pests. The bloom is particularly important as it can also help shield the fruit from ultraviolet radiation and assist in the overall health and integrity of the grape during its maturation process.

Understanding bloom is key in viticulture, as it is an indicator of the grape's natural defenses and can influence the quality of the wine produced from those grapes. This waxy layer can also play a role in the sensory characteristics of wine, influencing aspects such as aroma and flavor perception.