Pronunciation: [ɡɹˈe͡ɪp mˈə͡ʊld] (IPA) 
When it comes to the spelling of "grape mould," there are a few things to consider. First, the "a" in "grape" is pronounced as /eɪ/, which makes it a diphthong. Secondly, the "ou" in "mould" is pronounced as /oʊ/, which also makes it a diphthong. So together, the word is pronounced as /ɡreɪp məʊld/. This is an important aspect of English spelling and pronunciation to keep in mind when writing and speaking.
Grape mould refers to a type of fungus that commonly affects grapes, both in the vineyard and during the process of winemaking. It is caused by various species of molds, particularly the genus Botrytis, which includes the pathogen Botrytis cinerea. This mold often thrives in humid conditions and can have a significant impact on the quality and yield of grape crops.
Grape mould is characterized by the development of a powdery grey or brownish fuzz on the surface of the grapes. It typically begins by infecting damaged or overripe grapes, spreading rapidly to nearby healthy ones. Once established, the mold penetrates the grape skin, causing the fruit to deteriorate and facilitating the formation of additional fungi.
The impact of grape mould on winemaking can vary depending on the specific circumstances. Under certain conditions, such as in the production of sweet wines like Sauternes or Tokaji, grape mould can actually be beneficial. In these cases, the mold dehydrates the grapes, enhancing their sugar concentration and adding complex flavors to the resulting wine.
However, in many other situations, grape mould is considered undesirable. It can lead to a decrease in grape quality, affecting taste, texture, and aroma, and resulting in lower-grade wines or even complete crop loss. Winemakers employ various techniques to control grape mould, such as pruning to improve airflow, using fungicides, and carefully selecting the appropriate time for harvest to minimize exposure to the mold.
In summary, grape mould is a type of mold that affects grapes, primarily caused by Botrytis cinerea. Its impact on winemaking can be both positive and negative, enhancing certain wines while diminishing quality and yield in other cases.
The term "grape mould" does not seem to have a specific etymology. "Grape" refers to the fruit and "mould" refers to a fungal growth. However, these words do not have a particular origin related to the combination of the two words. It is likely that "grape mould" is a term that describes a specific type of fungal growth on grapes rather than a term with a distinct etymology.
