Full of beans

In part one of a two part series, consultant Graham Godfrey discusses the unique properties of cocoa and its role as a chocolate ingredient.

Chocolate is an ever popular flavour and a mainstay of the confectionery industry, but where does that unique flavour come from?

Of course there are many components to the flavour of chocolate, not just the cocoa derived flavours but also those from milk, added components such as malt or hazelnut and other flavours that are added to the product. On top of this is the wide range of flavour components that are created in the various chocolate making processes themselves. This article will consider only the cocoa based components.

Straight from the tree, the cocoa bean has no real cocoa flavour; that only emerges during the fermentation and drying processes it is subjected to, and these, together with some other parts of the primary process have the most significant effect on the quality and intensity of cocoa flavour in raw bean. This means that in addition to origin and variety, primary processing practices can affect the flavour of the bean significantly. What is more, some common processing techniques can adversely affect the flavour, particularly over fermentation and poor drying practices. The way in which cocoa is dried can significantly affect the acidity of the bean and high acidity will reduce the cocoa flavour contribution from the bean – in spite of some niche manufacturers trying to convince people that acid bean with poor cocoa flavour is a benefit.

Character

Certainly local differences in processing, and to a lesser extent agriculture, do have an effect on the character of cocoa, but good quality beans will always taste of cocoa. Many manufacturers have historically used a blend of beans from different origins to obtain their own characteristic flavour, but now it is not uncommon to buy mass and butter against a flavour definition and to leave how that flavour is obtained to the bulk processors.

It is important to remember that it is extremely difficult to remove undesirable flavours. Although water soluble components (such as acids) can be reduced slightly, this is usually at the expense of desirable flavours too. Few, if any, physical processes can differentiate between desirable and undesirable flavours and that these flavours are not in any case single entities, but are composed of a huge number of flavour chemicals derived from many sources. Both the absolute level and the relative ratios of these chemicals contribute to the overall flavour.

Having obtained good quality cocoa beans, the next thing to consider is the location of the key flavour components within those beans. The vast majority of the flavours are fat soluble and sit in the fat fraction of the bean. Therefore, cocoa butter is by far the most important part of the bean in pure flavour terms, although cocoa mass is the most intense source of flavour. Cocoa solids mainly carry the bitter and astringent notes in cocoa as can be established by comparing the flavour of cocoa mass with a natural cocoa butter derived from it.

Raw bean has to be cleaned, sterilised, winnowed (to produce cocoa nibs), sometimes treated and ultimately roasted before it is used for chocolate making, although some manufacturers do use cocoa butter from unroasted beans – generally extracted by mechanical expellers – for its unique flavour. Mechanical extraction of butter from poor quality bean followed by high level deodorising is also practiced, producing a relatively cheap, flavourless butter that can be used with care in blends.

The treatment of cocoa nibs using weak alkali solutions under various conditions is important in the production of coloured and solubilised cocoa powders for a variety of uses, including in bakery and other food and beverage products and in cocoa flavoured coatings. Some form of aqueous treatment (even with water, in which case the product is often referred to as untreated) is considered to be necessary if cocoa mass is to be pressed to produce cocoa powders and butter separately.

It is important to note that while high levels of treatment will produce dark colours, the flavour of the products from this sort of treatment will be adversely affected. Cocoa intended for cocoa mass for chocolate production is not normally treated. Although one or two manufacturers do attempt to treat cocoa mass (ie after roasting and grinding) with alkali before pressing, the effect is minimal as the cocoa solids, which are the target of the treatment process, are by then insulated from the treatment medium by being in a fat continuous medium.

The level of roast of the beans or nibs and the use of different roasting systems will have an important effect on the flavour of the end product. Roasting can take place in more or less fresh hot air, in an inert atmosphere or in a high humidity environment, all of which will produce slightly different flavour profiles.

Taste profile

Once roasted, the cocoa is ground to produce cocoa mass. Untreated mass is used for chocolate manufacture and is the strongest and purest flavour source for that product. Because of its strength of flavour (and cost in some cases) only a relatively small amount of cocoa mass is used in most milk chocolate products. Dark chocolate contains much higher levels

Too much cocoa mass in chocolate will produce a bitter, astringent taste, bringing the flavour contributions of the cocoa solids to the fore. Poor quality cocoa mass will produce a weak flavoured chocolate with acid notes further reducing the impact of the chocolate. Adding more of a poor quality mass is not the answer because the bitterness and astringency will continue to overpower the weak chocolate flavour. Any off flavours or excess acidity in the cocoa mass will also become very obvious once the mass is converted into milk or dark chocolate.

Cocoa mass that has been treated with water and/or alkali is pressed to produce cocoa butter and cocoa cake. The cake is ground to produce cocoa powder in a range of colours (from distinct reds to dark brown, almost black) and flavours depending on the source and primary processing of the bean, the treatment regime and the level of roast. Powders are generally produced with an 11 per cent or 22 per cent fat content. The former is about the limit that can be obtained by mechanical pressing; the latter produces a far superior flavour (remembering a high proportion of the flavour is in the fat phase) but at a higher cost as the cocoa butter is generally much more valuable than the solids.

The cocoa butter arising from the pressing process (‘natural’) has a strong flavour and if used in chocolate directly produces a harsh flavour profile that is unfamiliar to European and North American tastes. Most cocoa butter is subject to a deodorising process to reduce (but not completely eliminate) the flavour profile. Most manufacturers use a blend of natural and deodorised butters depending on the flavour profile they are seeking. As mentioned previously, some butter from raw beans is also used by certain manufacturers due to its unique flavour, which has long been part of their particular flavour profile.

Chocolate produced solely with natural cocoa butter does exist, mainly in Eastern Europe where this was the tradition and is therefore the preference of the consumers, although global products manufactured by western European and American producers are eroding that preference to some degree.

Cocoa mass

The level and flavour profile of cocoa mass will have one of the greatest effects on the flavour – and cost – of any product. Note that here I am referring to only the cocoa mass content, not the total cocoa solids, which include cocoa butter and possibly powder.

Describing total cocoa solids content is potentially misleading because it could describe a product with a small amount of poor quality mass and a lot of equally poor quality low fat cocoa powder and deodorised cocoa butter.

Cocoa mass contains a full spectrum of flavours, including the chocolaty and/or nutty components of its butter fraction and the bitter/astringent notes that predominate in the solids.

For a typical dark chocolate, the cocoa mass content can vary widely depending on the type of product. Some contain as little as 20 per cent cocoa mass, while at the other end of the spectrum there are products with over 50 per cent. Because cocoa mass is predominantly bitter and astringent, products at high mass levels do need good quality cocoa as a base and long, intense and high temperature conching to drive off acid notes and to bring all the flavour components together. At above about 60 per cent, cocoa mass may require the use of intense sweeteners and there have been products of up to 99 per cent mass with just intense sweeteners, but these are not particularly pleasant to eat.

Milk chocolate is milder in flavour and cocoa mass levels typically range from five per cent to about 10 per cent for common retail chocolate with higher levels for specialist products. Milk chocolate with a high level of good quality mass of up to about 15 per cent, which is finely ground and well conched, is almost a separate category of product and although expensive can provide a wonderful eating experience. In spite of its cost, a reasonable minimum level of good quality mass (say seven per cent) will make a huge difference to the chocolate flavour of any milk chocolate.

With both milk and dark chocolate it is possible for a finished goods producer to buy a good quality commercial product and then to add a little more cocoa mass to it to boost the flavour and make it more individual. Pre-processing the mass with heat or other techniques can enhance this effect further.

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