Location of production - Palm ‘wine’ is an important alcoholic beverage in West Africa where it is consumed by more than 10 million people.
Product description - Palm wine can be consumed in a variety of flavours varying from sweet unfermented to sour fermented and vinegary alcoholic drinks. There are many variations and names including emu and ogogoro in Nigeria and nsafufuo in Ghana. It is produced from sugary palm saps. The most frequently tapped palms are raphia palms (Raphia hookeri or R. vinifera) and the oil palm (Elaeis guineense). Palm wine has been found to be nutritious. The fermentation process increases the levels of thiamin, riboflavin, pyridoxin and vitamin B12. Like many African alcoholic beverages, palm wine has a very short shelf-life. The product is not preserved for more than one day. After this time accumulation of an excessive amount of acetic acid makes it unacceptable to consumers. The bark of a tree (Saccoglottis gabonensis) may be added as a preservative. The alkaloid and phenolic compounds which are extracted into the wine have antimicrobial effect (Odunfa, 1985) .
Preparation of raw materials - Sap is collected by tapping the palm. Tapping is achieved by making an incision between the kernels and a gourd is tied around to collect the sap which is collected a day or two later. The fresh palm juice is a sweet, clear, colourless juice containing 10-12 percent sugar and is neutral. The quality of the final wines is determined mostly by the conditions used in the collection of the sap. Often the collecting gourd is not washed between collections and residual yeasts in the gourd quickly begin the fermentation.
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Cut 10-15 cm from the top of the trunk |
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A gourd is fixed below the cut |
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The sap is collected each day |
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Natural fermentation starts as soon as sap is collected |
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Optional |
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Clean bottles should be used |
Processing - The sap is not heated and the wine is an excellent substrate for microbial growth. It is therefore essential that proper hygienic collection procedures are followed to prevent contaminating bacteria from competing with the yeast and producing acid instead of alcohol (Fellows, 1997) .
Fermentation starts soon after the sap is collected and within an hour or two, the sap becomes reasonably high in alcohol (up to 4%). If allowed to continue to ferment for more than a day, the sap begins turning into vinegar, although the vinegary flavour is preferred by some. Organisms responsible include S. cerevisiae, and Schizosaccharomyces pombe, and the bacteria Lactobacillus plantarum and L. mesenteroides. There are reports that the yeasts and bacteria originate from the gourd, palm tree, and tapping implements. However the high sugar content of the juice would seem to selectively favour the growth of yeasts which might originate from the air. This is supported by the fact that fermentation also takes place in plastic containers. Within 24 hours the initial pH is reduced from 7.4-6.8 to 5.5 and the alcohol content ranges from 1.5 to 2.1 percent. Within 72 hours the alcohol levels increase from 4.5 to 5.2 percent and the pH is 4.0. Organic acids present are lactic acid, acetic acid and tartaric acid (Odunfa, 1985) .
The main control points are extraction of a high yield of palm sap without excessive contamination by spoilage micro-organisms, and proper storage to allow natural fermentation to take place.
Packaging and storage - Packaging is usually only required to keep the product for its relatively short shelf-life. Clean glass or plastic bottles should be used. The product should be kept in a cool place away from direct sunlight.
Caution - Homemade coffees, wines and liqueurs do not have the shelf life of commercial brands! In many instances the use of extracts is preffered instead of cooking and breaking down fruits - to expedite the ageing process and prevent acidity or fruit sedimentation (this also sometimes prevents the natural flavours to permeate the liqueur)! Sugars, coffee, chocolates, and fruits added with water can introduce contaminants to liqueurs so refrigerate upon opening, serve and enjoy as soon as possible!