Beer making has been in vogue for thousands of years. It's probably one of the oldest alcoholic beverages that have been intrinsically linked to biotechnology although it has never been stated as such. This is because most of the processes involved in beer making are enzymatic processes. Different types of beer are made by using different ingredients and also different production techniques.
Before we go into how biotechnology impacts the production of beer, one must understand the different steps involved in the production of beer. The distinct steps in beer making are malting, mashing, sparging, boiling, fermentation and packaging.
Malting and Mashing
Malting is the process of making malted barley. First the dry grains are soaked in water. The soaked barley is incubated for several days so that it germinates producing amylases and proteases. In this process the starch that is stored in the grain is converted to maltose and proteins to amino acids.
However, enzyme supplementation is cheaper than malting process. Here's how it works. Alcohol is produced due to the effect of yeast on barley, maize and hops. More specifically, sugars in these materials get converted to alcohol and carbon dioxide. At times when yeast encounters sugars in complex polysaccharide form it is unable to convert it into alcohol. In such cases the process of malting becomes necessary. Since malting is not amenable to process control and is expensive the idea is to mimic this malting process by adding enzymes. On the whole, enzyme supplementation is cheaper than malting process.
Mashing involves the making of malt extract by soaking the crushed malted grains in warm water. Traditionally this process uses the enzymes present in the malt itself for the conversion of starch into fermentable sugars. In other words, the enzymes that are liberated during the mashing process are responsible for hydrolyzing the starch to fermentable sugars. However, as a result of advances in brewing technology exogenous enzymes are now used to quicken the fermentation process, and increase the overall yield including alcohol content. These exogenous enzymes work alongside the enzymes in the malt. One such proprietary enzyme is SEBamyl GL which is an amyloglucosidase that is capable of hydrolyzing 1, 4 and 1, 6 glucosydic linkages in starch.
Sparging is the step intended for dissolving the sugars to give a sugary liquid called the wort. This is done by filtering water through the mash.
Boiling is the step that ensures that microorganisms are destroyed. At this stage bitter hops and flavors are added to the boiling wort. Commercial beers have been brewed, employing nucleate boiling.
Fermentation is the stage at which yeast is added. Yeast is responsible for metabolizing the grain sugars. The result is alcohol plus carbon dioxide. Sometimes secondary fermentation is carried out after the first fermentation which allows settlement of particulate matter.
The main strains of yeast used for fermentation are:
Saccharomyces cerevisiae (ale yeast)
Saccharomyces uvarum (lager yeast)
Wild yeasts are used to make limbic beers. What is typical about brewing yeasts is their inability to reproduce. This means they can make alcohol only less than or equal to 12% abv.
For adjusting fermentation characteristics and especially for making low calorie beer Amyloglucosidase and pullulanases can be used. Efficiency of fermentation can be augmented by Acetolactatedecarbozxylase which is capable of reducing diacetyl formation.
Downstreaming comprise the steps of flocculation, filtration, clarification and maturation. Filtration is the step that follows the primary fermentation to remove particulate impurities. Beer has been traditionally filtered and clarified using kieselguhr also known as diatomaceous earth. But this creates waste disposal problems. Some filtration problems can be resolved by using β-glucanases. Enzymes augment the filtration process since they help reduce the quantum of xylans and glucans. That apart, beer filtration traits can be improved by using Betaglucanases and arabinoxylanases.
Isinglass sourced from tropical fish bladders is used for flocculation purposes and to give clarity to the liquid. Papain, α-amylase and β-glucanase can be used to control the haze. After flocculation and filtration the beer is subjected to chillproofing by precipitating the residual proteins using proteolytic enzymes. In the making of light beer, enzymes enable chill proofing and also helps get rid of the carbohydrates.
The clarifying agents used in beer making are mostly of biotech origin. Here are a few of the clarifying agents that are commonly used:
Kappa carrageenan that originates from seaweeds
Colloids from Red alga like Irish moss
Isinglass finings that are sourced from fish
Packaging is the stage at which carbon dioxide is added to the bottled or canned beer. Storage of beer can cause cloudiness. Proteases can resolve this problem.
Quality of water
Water is a key ingredient in beer making. For brewing pale lager and ale, soft water is required. Dark beer is best made from hard water. Beer quality is also intrinsically related to the quality of foam. Some of the biotech ingredients that support foam are protein complexes like hydrophobic proteins.
That apart, biotechnology has a vital role to play in certain key aspects of beer manufacturing processes. Here are a few of them.
Control of yeast vitality
Yeast that is stressed is not conducive to fermentation. In preventing the yeast from stress, yeast vitality has to be controlled. Stressed yeast is a result of higher cellular growth and quicker aeration---biotechnology helps to resolve some of these problems. Ultimately, the vitality of the yeast reflects on the finished beer quality. From this perspective, biotech oriented changes have occurred in pitching of yeast and storage. For example, during fermentation the cytosolic p H of yeast is monitored to ascertain its vitality and also to arrive at the point of cropping from fermenter.
Biotech advances in the quality of brewer's spent grains
Usually the spent grains in a brewery are used as ruminant feed. But now using biotechnology this can be categorized into:
High protein faction suitable for use as pig and poultry feed
High fiber faction which can be used as feedstock for power generation
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