Im sure the answer to this question changes with price point and how biodynamic/green the winery is but im curious as to what goes into the wine except grape juice.
1 - I know that some form of sulphur is used to stabilize the juice and stop a lot of bad things happening
2 - Egg whites are traditionally used for fining
But what other things go in that are not so well known I believe that a lot of low end wines use Mega Purple as a colouring agent to darken the wine, so what else happens ?
Even the “high end” wines contain additives from the catalogs above. In great years the wines make themselves. In poor years, the winemakers use the toolbox available to them (read: additives) to make sure you get wine that tastes like you expect.
The mega producers are in a worse spot with quality year in and year out, hence the the more drastic interventions like mega purple.
Bottom line is creating what you want from what you get (i.e. grape quality) isn’t always “natural”.
Other stuff that can go in:
Other grapes (typically up to 10-20% depending on the region) into varietal wine
Other vintages (typically up to 10-20% depending on the region) into vintage wine
No idea how widespread this is, but I suspect many US wines available at retail for less than $10/bottle have this kind of stuff (H2O2) going on. A chemist who worked at a winery/lab in Lodi clued me in to this, also confirming the use of Mega Red and Mega Purple.
From Winebusiness.com
“Hydrogen Peroxide (H2O2) is a powerful oxidizer and can be used to reduce SO2 level in wine.The H2O2 should be added slowly to the wine in a dilute form to avoid oxidation. After the H2O2 addition,wine should be allowed to equilibrate for several hours before any confirmation analysis of the concentration of remaining SO2 in the wine. To avoid over adjustment and oxidation, lab trial should be performed.”
I wonder when the day will come that wineries will have to call out their ingredients and additives on the label along with the nutritional content. I never thought I would see it at fast food places. Maybe wine is next?