In this article we will discuss about:- 1. Introduction to Vanilla 2. Curing or Fermentation of Vanilla 3. Extraction 4. Classification 5. Usage.
Introduction to Vanilla:
Vanilla is undoubtedly the most popular flavour for ice cream throughout the world. In the United States of America, records show that about 75 per cent of all ice cream produced contains vanilla flavouring. It may be kept in mind that vanilla is often used in combination with other flavours or as a background flavour in many ice creams.
Vanilla flavouring is obtained from the perennial climbing plant, Vanilla Planifolia Andrews, a member of the orchid family. It is a native of Mexico and was introduced to the civilized world by the great Spanish explorer, Hernando Cortez, in 1528.
The above plant and its related types have been introduced to other tropical regions such as the Madagascar Islands (now providing 80% of the world’s supply), Indonesia (Java), certain islands in the West Indies, Mauritius, parts of Central and South America, etc.
Vanillin is the principal flavouring material in vanilla. However, there is no free vanillin in the beans when they are harvested, and the typical vanilla flavour is developed by fermenting the bean. Artificial or synthetic vanilla is a product of a slightly different flavour than the natural one.
Curing or Fermentation of Vanilla:
The vanilla plant can be grown only in tropical regions where climate, moisture and soil conditions are just right. The plant flowers during the second year, when the finest ones are promptly fertilized by hand. The development of the fruit or bean-pod follows. The mature fruit has little flavour and is yellow in colour; when ripe, they are harvested and sold to the curer.
Although the curing or fermentation process differs in different countries, it usually consists of a process called ‘sweating’ in which the beans are alternately dried in the sun and wrapped up in blankets at night so that they heat and ferment. This sweating process continues for approximately 4 weeks to 4 months.
In the course of this process, an enzymatic reaction takes place and the complex fats, resins, tannins, essential and fixed oils, vanillin and other aromatic compounds are formed. (At least 28 distinct components have been isolated from the vanilla aroma, most of them still unidentified.)
At the end of the curing period, the pods are carefully sorted out into various grades based on their quality. The colour now ranges from chocolate to almost black. They are then packed and shipped to their final destination where extraction will take place.
Extraction of Vanilla:
Extraction of the vanilla flavour from cured beans is a delicate process, and much depends on the skill of the person carrying out the operation. Unless correctly treated at this stage, the true flavour of the vanilla from the beans will be ruined. The beans are first chopped by extra-fine knives. A solvent such as dilute ethyl alcohol must be used for extraction.
The alcohol content of the extract varies between 35 to 50 per cent. The extract is obtained through a process of percolation, which consists in continuous circulation of the alcohol-water mixture (with or without sugar and glycerine) over the chopped beans, under precisely controlled conditions, until the extraction is completed.
Classification of Vanilla Flavourings:
Vanilla flavourings may be grouped under the following general classes- true vanilla flavourings; compound vanilla flavourings and imitation vanilla flavourings.
1. True Vanilla Flavourings:
These may be sub-graded as:
i. True Vanilla Extract:
This is prepared by the extraction of finely cut vanilla beans by a solution containing not less than 35 per cent ethanol. A standard single-strength pure vanilla extract contains soluble matter to the extent of 13.35 ounces of the vanilla beans (with or without added sugar glycerine or colouring matter) per gallon of extract. These true vanilla extracts are generally of such a strength that only 5 or 6 oz. of the extract are required to flavour 5 gallons of ice cream mix.
ii. Concentrated Vanilla Extract:
This is obtained by distilling off a large part of the solvent until the strength reaches the desired concentrations, which is then specified as ‘two-fold (or double strength)’, ‘three-fold’, etc. A two-fold extract would be twice as strong as the single-strength extract, and would therefore contain the extractives from 26.70 oz. of vanilla beans per gallon.
iii. True Vanilla Powders:
These are made either by mixing finely ground vanilla beans with sugar, or by incorporating the vanilla extractives with a dry carrier, and evaporating and drying the solvent. The amount used would correspond by weight to the number of ounces used of a standard strength extract.
iv. Vanilla Paste:
This is made by mixing the concentrated extractives with a dry carrier to form a paste. The amount used would be the same as for powders.
v. True Vanilla Flavour:
This conforms to the same standards as for vanilla extract, except that it contains less than 35 percent alcohol, propylene glycol or some other solvent being used as the carrier.
2. Compound Vanilla Flavourings:
Reinforced Vanilla:
Not less than one-half of the flavour may be derived from the vanilla bean content. Not more than one ounce of vanillin should be used in conjunction with 13.35 oz. of vanilla beans. This type is also available in various degrees of concentration.
3. Imitation Vanilla Flavourings:
Blends:
These are composed of true vanilla extract, flavour or powder with added synthetics where less than half of the flavour is derived from the vanilla beans.
Synthetics:
These are preparations that contain no vanilla bean extractives and are made up entirely of one of several combinations of substances, such as synthetics and natural extractives derived from sources other than vanilla beans. These preparations may contain added water, alcohol, propylene glycol, vanillin, caramel, colour, etc.
Usage of Vanilla:
The amount of vanilla used in flavouring ice cream depends on the concentration of the vanilla flavouring material and the composition of ice cream. Vanilla flavouring is available in liquid or powder forms such as pure vanilla, reinforced vanilla with vanillin, and imitation vanilla. Concentration ranges from single strength (extractive from 13.35 oz. of vanilla beans per gallon extract) to a ten-fold or higher concentrate.
Vanilla may be used at rates ranging from ⅛ oz. to 5-6 oz. per 10 gallons of ice cream, depending upon the extract concentration. The amount of vanilla required decreases with decrease in the fat content of the mix and a low sugar level requires a higher vanilla level. An adequate amount of the best quality flavouring material should always be used. The vanilla flavour in the mix should not be too pronounced.