The most common reason given for wanting to leave out sulphites is a worry over allergic reactions. If a true allergy is at issue, leaving out the sulphites will not render the wine sulphite free, as yeast creates sulphites during the fermentation process. If a sulphite sensitivity is the worry, know that the amount of sulphite added to these kits is far less than required for commercial production. Often reactions to drinking wine are due to other causes and not the sulphites. (For a complete discussion of this topic, see our article “Red Wine Headaches – a thing of the past with Home Vintner wine kits.”)
The other common reason for wanting to leave out sulphites is the desire to have a “natural” product. Without any added sulphites a kit will oxidize and spoil very rapidly. It will start to go off in less than 4 weeks, and will be undrinkable in less than 3 months. If the sulphite is left out, but the sorbate is added, the wine will be attacked by lactic bacteria, which will convert the sorbate into the compound hexadienol, which smells like rotting geraniums and dead fish.
Winexpert uses sulphite as an anti-oxidant. It prevents oxidative browning and that stale, sherry-like smell. Sulphite and sorbate inhibit the reproduction of spores, moulds, fungi, and yeast.
The deal is, spoilage organisms in very small groups are not a danger to the wine. It’s when they multiply up to “culture strength” that they can do damage to the wine. By fermenting the wine dry, we remove the sugars that they would need to multiply. By fining, we reduce the populations significantly. By filtering, we reduce it a bit more. By adding sulphite and sorbate, we prevent the populations from rising again, and spoiling the wine.
These kits have only enough metabisulphite to hit 16 – 25 PPM at bottling, less than one-quarter the usual human threshold for detection, and far less than required for commercial production. A sulphite aroma can be common in young wines and decanting them for half an hour really helps. Fermentation can produce compounds that are full of Sulphur, which can smell skunky or sometimes like cabbage. This smell is re-converted (or dissipates) after fermentation is complete.
The Home Vintner and Winexpert guarantee our wine kits when made using the items provided with the kit to keep them balanced and fresh.