PROCESS

NOTES

Pulp

Procedures to produce pulp shown in Diagram 3.1.

Mix ¬ sugar syrup

Mix a 20% solution of sugar in correct proportion with pulp.

Ferment ¬ yeast + nutrient

Add yeast (2% by weight of pulp/sugar) and yeast nutrient (approx 1g per litre). Fit airlock (Fig. 10) and maintain temperature at 30° C. Ferment for 3-7 days or until gas production ceases.

Filter

Remove yeast and fruit pulp through fine cloth, sterilised by boiling for at least 10 min.

Clear

Replace in fermenter and add clearing agent (e.g. gelatine). Some pulps (e.g. banana, citrus) may also need pectolytic and/or amylolytic enzymes to produce a crystal clear wine. Decant cleared wine from sediment.

Ferment ¬ acetic acid

Add acetic acid bacteria (or less desirably bacteria allow natural contaminating bacteria to act) and ensure a plentiful supply of air to convert the alcohol in the wine to acetic acid.

Filter

Remove cloudiness using a fine cloth, sterilised by boiling for at least 10 min.

Standardise

Adjust the acetic acid content to 6-10% by blending with other batches and/or distilling part of the vinegar.

Fill/seal ¬ Bottle + cap

Bottles and caps sterilised by boiling in water for minimum of 10 min. Fill into cold bottles. Simple bottle capping machines are available (Fig. 15).