Can a synthetic version of wine be made that lacks the various wine faults that happen to regular wines?
There are many situations that wine develops an unwanted off flavor, the main ones being problems during the production of wine, the storage of wine, and also chemical reactions that occur after wine is exposed to air when opened. In theory all of these issues can be solved by making synthetic wine, but the one that come to interest the most is the last one, imagine a wine that can be opened and than stored indefinitely with minimal changes to the flavor profile, much like how most distilled alcohols are minimally effected by time. In natural wine compounds such as Acetaldehyde has a negative effect on the wine over time, as it reacts with the ethanol in wine and produces off flavors, the goal of making a synthetic wine is to make one that lacks the specific compounds that cause it to degrade, such as acetaldehyde and acidic acid while keeping as many of the desirable qualities as possible.
The most significant thing that would need changed to produce a long term stable wine is either the addition of a preservative or the addition of alcohol. For my method I will focus on raising the alcohol content of the formulation to 18% alcohol by volume, which will render the final product perfectly shelf stable.
Lets start by looking at a couple of 'recipes' for synthetic wine, the first is a recipe listed as part of documentation for a synthetic wine project, the second is taken from a paper looking at the aroma compounds in wine and analyzing how much limonene has an effect in the formulation.
Here is the first list of the ingredients used to make synthetic wine according to this chart-
Alanine- slightly sweet and slightly bitter
Proline- slightly sweet
Glycene- sweet and slightly meaty
Tartaric Acid- Clean sourness with medium strength, grape like
Malic Acid- Sharp acidity with a puckery bite, like apples and sour candy (think warheads candy)
Lactic Acid- Funky and sour, common in fermented foods, more vinegar like than citric acid like
Fructose- Sweeter, common sweetener aftertaste.
Sucrose- Less sweet but more fruit like, a common sugar and considered to have the best mouthfeel and most natural aftertaste
Ethyl Butyrate- Fruity, pineapple like, boozy, ethery
Isoamyl Alcohol- boozy, banana, whiskey
Limonene- Comes in two isomers, wine has both-
Now this list offers a good start to understanding the aroma compounds and some of the amino acids that are in wine, but is far from complete for making a decent of usable artificial wine. A more complete list, specifically of aroma compounds can be pulled from this paper-
diacetyl (2,3-butanedione)- butter, caramel, sweet creamy, pungent
hexanol (hexan-1-ol)- fruity, green, boosy, gasoline like
methionol- potatoy, tomato like, musty, earthy, and creamy
isobutyric acid (2-methylpropanoic acid)- rancid, buttery, cheesy, sour, acidic
2-methylbutanoic acid- pungent, cheesy, blue cheese, acidic, fermented
isovaleric acid (3-methylbutanoic acid)- cheesy, dairy, feet, sweaty, slightly fruity
isobutyl acetate (2-methylpropyl ethanoate)- sweet, fruity, tropical, banana, ethereal
D-Limonene- Citrus, fresh citrus, indistinct citrus notes, not complex
L-Limonene- Turpentine, Pine, Bergamot, some citrus notes
ethyl phenylacetate- sweet floral, rose, honey, balsamic, cocoa
ethyl 3-methylbutanoate- fruity sweet, apple, pineapple, tutti fruiti
ethyl 2-methylpropanoate- rum, sweet, ethereal, alcoholic, fuel like
ethyl 2-methylbutyrate- sharp, green, apple, fruity
ethyl butanoate (butyrate)- sweet fruity, pineapple like, boozy, ethery
ethyl decanoate- waxy, sweet, fruity, apple, grape brandy
ethyl hexanoate- Waxy pineapple, like pineapple skin
ethyl octanoate- winey, fruity, pear, apricot, brandy
butanoic acid- sharp, cheesy, acidic, buttery, fruity
decanoic acid- rancid, sour, fatty, off citric
hexanoic acid- fatty, cheesy, goaty
octanoic acid- fatty, cheesy, rancid, boiled vegetables
isobutyl alcohol (2-methylpropan-1-ol)- ethereal, wine ike
ethyl acetate- weedy, green fruity, ethereal, grape
isoamyl acetate- boozy, banana, whiskey
There is also the addition of some acetic acid listed, which occurs naturally in wine, but for our purposes needs to be excluded as it will react with the ethanol and produce more ethyl acetate, which will change the wine over time and eventually become strong enough to be an off flavor. This is one of the processes that leads to wine spoiling in ordinary circumstances. We can use lactic acid like listed in the first synthetic wine recipe we saw above.
Now with the above list we have a much better idea of the main aroma chemicals in wine. Though naturally made wines can have over 1000 different aroma compounds, many of them are below detectable thresholds. Many of the aroma compounds can also be approximated with other aroma compounds that are easier to obtain as well as approximations that may have better material, aroma and flavor properties to them. With 20 or so aroma chemicals most flavor profiles of different wines can be achieved. You may note that a lot of these compounds have off sounding profiles, indeed they do, but are each present in a small amount and represent the complexity of the profile of the flavor and scent of wine. When making a synthetic wine, these compounds can be selectively chosen to exemplify the specific amounts of off flavor wanted in a recipe. In this way a wine that tastes cleaner than reality may allow can be made, but it is recommended to still keep at least some of unpleasant sounding these compounds in the formula as too many clean flavors alone will taste artificial, and candy like.
The amino acids listed above alanine, proline, and glycene are interesting, and I am left unsure why the original recipe I found lists them at all given that each of them as a pure amino acid has little flavor to add to a wine, there is a chance they contribute to the mouthfeel or perhaps modify the perception of the sugars in the wine giving it a more natural feel. I suspect that these were intended to be amino acid salts, which would offer up an umami/savory quality which many wines have. I recommend out right replacing these for readily available amino acid salts such as Monosodium Glutamate, Disodium Inosinate, and Disodium Guanylate. The amounts of these needed to add an umami note to wine would be incredibly small, but not too dissimilar to how artificial grapefruit juice has them added to replace mercaptan notes.