About Sulphites
Sulphite is one of the top ten causes of allergic reactions in food. Meta-bisulphite and potassium bisulphite are used in wine making as preservatives to maintain color, prolong shelf life, and prevent the growth of micro-organisms.
Making wine at home without the use of sulphites is extremely challenging. It is used to sterilize equipment; it is used to sterilize the must by killing all the naturally occurring yeasts so the preferred strain of yeast can be added; it is used to protect the wine from oxidation especially during each racking; it is used before bottling to prolong the shelf life of the wine once in the bottle. Not keeping the appropriate levels of SO2 while making wine is inviting micro-organisms to enter and ruin your efforts.
If you have allergic reactions to sulphites, the following article contains information about sulphites and allergic reactions.