Hello all from the ATL!

[JoshFelix]

Newbie here [with a question] looking to learn from others' expertise.

What compounds or fruit characteristics contribute to wine having 'structure'? And [how] does it correlate a wine's ability to "sit down" for a year, 5 years or even 15?

To ask it another way, if i were to look at the chemical composition profile of a wine, what are the ingredients that indicate when it is at its peak drinking form (ie singing)?

 

[my wine]

I can't tell you the specific chemicals you are asking about but it has something to do with magic.

And welcome to WMT!!

 

[sour_grapes]

I also welcome you to WMT!

AFAIK, the number one class of chemical allowing wine to age gracefully for ~decades is tannins. They take a long time to settle down.

 

[Rice_Guy]

Welcome to wine making talk, excellent question, ,, possibly more answer than you want.

The issue related to age is basically how to minimize the oxidation reactions. Number one is to do larger batches with a lower percentage of head space (ullage). Going along with this a commercial winery will flush equipment and transfer lines with nitrogen or CO2. For home I would say collect a series of carboy sizes or glass marbles. The number two tool we all have is metabisulphite or commercially SO2 gas which will combine with free oxygen(DO). (It is also worth while to look at the factors involved in the Winemaker Magazine sulphite calculator since wine is a synergistic preservative system.) A third tool we all have is run high on the alcohol. An 18% ages better than a 14% which is better than 12% which is better than 10% etc.

Sour mentioned tannins are added to country wines and white grape. Be aware that there are a variety of tannins on the market that the local wine toys shop probably doesn’t carry (see Scott Handbook). Some tannins produce better flavor on whites and country wines. (FT Rouge) Red grape also have color pigments (phenolics) which are anti oxidants so reds always survive better and a long life tannic red wine may not be good young. The AWRI and enology departments ate also working with chemical solutions as glutithione but this gets into legal definitions so it isn’t wide spread.

Next look at closures. Natural cork leaks oxygen and synthetic is being manufactured in several grades which can mimic natural transmission. Aluminum caps are the best closure available. The next generation aluminum cap looks like an oxygen absorber will be inserted in the Saran plastic seal, but that isn’t available yet.

Body,, number one tool is high solids. For country wines this is use more fruit, even 100% juice and then pull the acid out or back sweeten to balance the acid. Next some yeast will produce higher levels of glycerin which is also available if you wanted to add it straight. Less common will be gum arabic but a good viscosity agent. A note on solids, measured viscosity is related to the log of the solids, so gums which bind water give you more bang for a kilo of ingredient.

I take ATL might be Atlanta a temperature controlled wine cellar will also help. Again welcome.

 

[winemaker81]

As has been mentioned, tannin and glycerin contribute to structure, as does acid. For non-dry wines, sugar does as well.

Oak adds structure as well, constituents beyond tannin. Fermentation extracts other constituents from the grape skin & pulp, and as @Rice_Guy mentioned, winemakers can add various enzymes to improve extraction.

Tannin, glycerin, and acid (tartaric, malic, lactic, citric, etc) are known. I have no idea what the other constituents are.

 

[Handy Andy]

Leaving your fruit to ripen reduces the acidity and increases the sugars. Using ripe fruit, ( not lemons ) helps ensure your wine is not too acid.