The purpose of malting in the beer brewing process is to activate the endogenous phytohormones and enzymes of barley to make it more amenable to milling and starch/carbohydrate extraction.
The malting process key steps are:
Barley cleaning and grading
Barley is cleaned to remove stones, metal fragments and foreign material and vegetation. It is graded according to size to ensure an even germination/modification during malting.
Barley is submerged in water (12-15 °C) to increase the moisture content of the grain.
The malt moisture content is reduced in a controlled manner to ~5%. This arrests the development of the embryo, ensuring that valuable brewers extract is not expended. Prior to milling, the malt must be cleaned (to remove roots, culms and foreign grains) and graded (to be sure that the malt mill settings are correct and do not require continuous adjustment).
Mashing during the beer brewing process provides the proper conditions for the production of brewers extract from the grist. During mashing, malt or solid adjunct is converted into a fermentable extract suitable for yeast growth and alcohol production.
Due to the use of adjuncts such as barley, wheat, maize and rice and also as a result of environmental conditions, it can be difficult to process malts in a brewery. To overcome this, exogenous enzymes an be added during the beer brewing process to maintain consistent brewhouse performance and ensure extract quality and yield. These products also ensure a brewer continues to produce high-quality extract in the most cost-efficient way. Kerry offers a complete range of amylase, glucanase, cellulase, hemi-cellulase and protease enzymes to ensure consistent and cost effective brewhouse throughput.
The enzymes involved in the hydrolysis of starch during the beer brewing process are α-amylase (e.g. Bioferm™, producing dextrins and maltose) and amyloglucosidase (e.g. Amylo™ for glucose and “low carb” beer production). The combined actions of these enzymes help to produce a wort sugar spectrum suitable for fermentation. For starch liquefaction and/or extract production from adjuncts, it is recommended that Hitempase™ is added to the cereal cooker.
β-Glucan (a non-starch polysaccharide) is a major constituent of malt and of barley cell walls. If malt is poorly modified, or if the brewing process employs a significant proportion of unmalted barley, the β-glucan released during mashing will be insufficiently hydrolysed. The resulting gums can increase wort viscosity and significantly reduce the porosity of the grain bed, resulting in poor lautering/mash filtration performance. β-glucan that passes through the grain bed in the wort will survive in the beer and may cause filtration problems or lead to the formation of β-glucan haze in the final product. Malt β-glucanases are temperature labile (max. 60°C); any that are not destroyed during the kilning process can survive for a limited period during mashing. Kerry’s glucanases, under the Bioglucanase® range, can be used in both mashing vessels and fermentation/maturation tanks to hydrolyse malt/barley β-glucans and remove large beta-glucans from wort and green beer.
In instances where there is a significant percentage of unmalted barley, or when another adjunct is used, there is the danger that insufficient nitrogen will be available for yeast growth, meaning fermentation may be sluggish. Kerry’s Bioprotease™ range is used to increase wort free amino nitrogen (FAN) levels.
Use of glucanases, proteases, amylases and xylanases during the beer brewing process can help to significantly reduce viscosity levels within the mash, thereby standardising or controlling wort filtration rates. The Promalt™ range provides these enzymes in a single addition.
The major objectives of the wort boiling process are summarised below.Objectives of wort boiling
Our Whirlfloc™ range ensures more rapid and consistent coagulation of wort hot and cold break proteins, thereby optimising trub formation, reducing expensive wort losses (in poorly compacted trubs) and ensuring bright, clear and consistent worts for fermentation.
Hitempase may be added to a kettle in circumstances where wort is still starch positive or suspected of having a significant level of potentially troublesome dextrin.
FermCap® can be used in the copper to reduce expensive wort losses due to over boiling and to improve on subsequent brewhouse and tank cleaning costs.
Wort Clarification, Cooling and Aeration
Whirlfloc added towards the end of the boiling process facilitates protein coagulation, formation of a compact trub and the production of clear worts.
The hot wort is then cooled by passing it through a plate heat exchanger (paraflow) and aerated by direct injection of sterile air or oxygen.
Enzymes such as Bioferm and Amylo may be added at this stage of the beer brewing process to increase wort fermentability (and to remove potentially troublesome dextrins from the wort. Bioglucanase may be added to reduce beer filtration problems and ß-glucan gums and hazes in the final product.
In high adjunct brewing, using nitrogen as a source of food for yeast may be limiting. In this instance, specifically developed yeast foods (Yeastex™) may be added as both nitrogen and vitamin supplements.
Occasionally there may be a problem on the fermentation side of the beer brewing process with excess fobbing or foam formation in tanks. This can reduce hop utilisation, reduce fermentation capacity, increase fouling of vessels and cause poor foam stability due to the loss of valuable foam-positive materials. In some cases, this can also result in problems with beer filtration and hazes due to collapsed foam.
These problems can be alleviated by using Kerry’s FermCap range of products, which control foaming during fermentation.
At the end of maturation it is important to remove as much yeast as possible prior to filtration. This will significantly reduce the solids loading on the filter and prolong filter run times. Increasing filter run length and reducing filter-aid consumption usage rates can have significant cost saving and quality benefits in a standard process. The Biofine™ range of products have been designed and optimised to give brewers these significant cost control and quality improvements.
The enzyme Profix™ may be added to beer prior to pasteurisation to control chill haze formation.
The quality, amount and stability of beer foam dispensed from either a small package or tap is an important characteristic of the product. Even in normal dispense environments, numerous external and internal factors—such as malt and hop derived lipids—may adversely affect beer foam stability. Biofoam™ products are recommended for beer foam creation and stabilisation.
Beer flavour stability is an absolute requirement for the final packaged product. The negative effects of oxygen uptake during packaging or flavour active precursors can be eliminated using our specially designed antioxidant system, Biox™.