(or "of the berry") one of the last phases of the grape, which is still a berry - softening then changing color...
https://theses.cz/id/i108z6


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Note added at 21 mins (2017-06-22 12:27:00 GMT)
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from Wiki:
"In many ways, the concept of physiological ripeness is similar to the French notion of engustment (from the Latin root gustis or taste), the stage of ripening when aroma and flavor become apparent."
(https://en.wikipedia.org/wiki/Ripeness_in_viticulture)
I believe that during engustment they do soften...I think this depends on the audience...unless its in some "fajnsmekrovsky degustacni odborny casopis..." I would use softening because it's clear and to the point..engustment seems more in relation to its development of aroma, but in that stage apparently they are softening...any fruit that softens releases its essence I guess...as far as veraison, I believe this is more a general term, not specifically meaning "softening"...from Google search: In viticulture (grape-growing), veraison is the onset of ripening. The term is originally French (véraison), but has been adopted into English use. The official definition of veraison is "change of color of the grape berries".



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Note added at 22 mins (2017-06-22 12:28:32 GMT)
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and let us not forget the root of zaměkání comes right from změknout...to soften...pretty clear :)


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Note added at 1 hr (2017-06-22 13:07:41 GMT)
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right...I mean we could say we masticate our food, but why not say chew? KISS rule....And readers don't like to reach for dictionaries, especially non-native English speakers ;)