Fruit maturing model

Ben,

Nice work. Visual learners like me appreciate it

Did you intend to leave the trend for Ph out of the chart? I see you listed it in the key. Also, I feel the upper vegetal flavour trend is more realistic, as it seems to reach high levels early in the season.

HTH, Mike MTM

Mike,

Thanks for the comments.

Yes, I was waiting to hear what others thought on this. (?)

OK. Perhaps a shallower slope and a peak a little earlier than veraison would better represent this?

Ben

Try this page:

Even Peynaud is vague in reference to pH and acid trends before veraison.

the upper vegetal flavour trend

It's just an opinion, but that sounds reasonable.

HTH, Mike MTM

Good work! Your graph shows how all the factors for grapes come together during ripening. What do you mean by tannic ripeness? How would you measure it? How would use your graph to help one determine grape ripeness and the optimum time to pick?

Joe

Thanks Joe.

All these questions will be answered in an article I'm currently writing for my website on assessing fruit maturity (which is what this graph is ultimately for). In short:

As a fruit matures the phenolic compounds contained within polymerise with other molecules such as sugars and proteins. This results in an organoleptic change with hard, bitter tannins becoming more astringent, soft, and supple. "Tannic ripeness" is a pre-defined point at which the tannins are considered mature enough for use in making a wine of a particular style with particular fruit.

Accurate measurements of tannin (which is a catch all term for many non-volatile phenolic substances) can be made using various chemical assays (it's commonly for a spectrophotometer to be used). However, most home winemakers don't have access to the chemicals or equipment necessary for such tests and rely on tasting the fruit and assessing the character of the tannins.

To determine the extent of maturity many fruit attributes can be assessed (e.g. sugar and acid concentration, aroma and flavour profile, tannic ripeness). The graph simply shows the trends of each of these attributes as the fruit ripens. A fruit might have a high sugar content yet, upon tasting the skins, still have very harsh and astringent tannins. It may therefore be left on the plant to mature further. Of course it depends on the fruit as to what constitutes "very harsh" tannins and the taster is required to know what this means in terms of that particular fruit's stage of maturity.

All these attributes will be covered more in the coming article. If you're interested, I'll post a message when it's complete.

Ben

Improved Winemaking

Thanks Ben!

Look forward to reading your article.

Joe

optimum > time to pick?

Ben Where is your article?

Vinny

Not quite finished yet (just putting in some info on assays). Shouldn't be too long before it's up on my website: Improved Winemaking

Ben