Since you aren't convinced by me alone here is a reference to the method that gives some numbers. This reference was for Pinot Noit an uses intact clusters.
It is common to add a proportion of whole clusters (uncrushed, with stems intact). Rates typically vary in the range 0-50% but the most common rates used are 10-30%. Whole berries ferment slower and tend to maintain lower temperatures, which potentially preserve/increase fresh fruit aromas. Whole clusters also enhance spicy (vanilla, clove and cinnamon) characters, and give softer/smoother tannins. The inclusion of whole clusters can also assist in drainage through the cap resulting in better structural and aroma/flavour extraction.
Also look up Whole Berry Fermentation . You also may want to look up carbonic maceration.
<H4>Carbonic maceration</H4>Some Pinot Noirs are fermented with limited carbonic maceration. This process involves placing the whole grapes in a tank which is filled with carbon dioxide (to prevent oxygen contact). The enzymes present in the grapes then convert sugar to ethanol up to about 2% abv, after which pressing takes place and the fermentation is completed with yeast.
When a significant factor in making Pinot, whole berries or grape bunches (10-20% for minimal effects, or 30-40% for a more overt effect) may be included in the must. The effect of carbonic maceration is to give a softer wine (less acidity and tannin), with a more fruity (and sometimes quoted spicy, e.g. cinnamon) character.
Again I say you are treading on advanced techniques and might want to wait until you have the basics. Kind of like wanting to make a rocket to the moon after flying a little solid booster model rocket.
