Yeast propagation

Propagation of bottom and top yeasts in a one-tank process has been investigated in an extensive test series, with special emphasis on flocculation behaviour of flocculent yeasts in subsequent fermentations. Apart from checking the influence of propagation temperature and aeration, pure culture wort concentration and propagation time on yeast reproduction and yeast vitality, tests were made aimed at finding ways of avoiding the slightly more powdery character of flocculent yeasts during the first commercial propagation cycle, a phenomenon frequently observed.

Optimising brewers’ yeast process cycles using fluorescence optical methods

A rapid check on functionality of brewers’ yeasts in technical processes has become feasible in recent years as a result of development of new measurement techniques. Flow cytometry is eminently suited as a reliable fast method for this purpose.

Cell contents are fluorochromed
and quantitatively measured. The result is a characteristic cell condition description which is a reflection of the functionality of a yeast cell. Process
parameters can be adjusted in a very simple and easy manner such that brewers’ yeasts perform optimally in short time intervals during pure culture, pitching and in fermentation. This is understandable because their presence leads to heavy commercial losses.....

Crate hygiene management

All food and beverage processors have a legal responsibility to ensure that all factors contributing to product safety are operating consistently and effectively. This also includes the hygiene status of crates and trays. A focus on safe processing is understandable but how products are packaged, stored, transported and displayed are crucial to final product quality and company image.There are increasing demands for product quality and safety coming from consumers, retailers and legislators. This demand is affecting crates used in all industries from Food and Beverage to logistics services and automotive. In addition, the industry is faced with ever changing soil types and contaminating micro-organisms that together, need to be controlled..

Nutrient media for microbiological quality control

High-value products with consistent quality are a basic prerequisite for maintaining market position. This objective can be achieved only when the operation carries out fully comprehensive production control checks. Microbiology is a very significant parameter in this quality assurance.
Spoiled products, a health hazard under certain circumstances, have to be recalled from end-users in the worst case. Serious commercial consequences can even lead to the supplier disappearing from the market, as examples in the past have shown. Product liability claims may also arise when it is proven that defective good were put on the market as a result of indequate microbiological quality control. In order to avoid recalls and the associated loss of image, product liability proceedings etc.g.

New quality control equipment and "CO2 4U"

As a specialist in the field of quality control and carbon dioxide Haffmans, from Venlo/The Netherlands presented new innovations in these fields. The well-known foam stability tester "Nibem-T" is extended to measure and compensate atmospheric pressure and relative humidity to secure a very accurate foam stability measurement. The range of foam measurement equipment is completed with the "Nibem Cling Meter" to further measure the quality of beer foam, which is one of the most determining quality parameters of beer. Based on the proven Haffmans method to measure CO2 in bottles and cans a new automatic CO2 tester was presented..

CO2 in-line measurement to secure product quality

The continuous and direct monitoring of the CO2 measuring values with a continuous measuring system results in an increased accuracy and the product quality will be more constant. The values can be recorded in detail on-line and information is given regarding the condition of fermenters, tanks and filling machines. At the private brewery Hoepfner in Karlsruhe, Germany, the biggest European Keggy filler, the product safety of these special bottles and cans is added to it.

The content of dissolved CO2 is a decisive factor in the taste of the beer. It also influences the accuracy of other measurements, such as original gravity. A later carbonisation causes considerable costs in beverage production. This constant high quality along with a well-known taste is the highest goal and aim.

Biofilms in breweries and in the beverage industry

The study of biofilms in breweries and beverage operations has been carried out systematically worldwide over a period of about 15 years. In the study, swab samples together with NBB broth (more recently with NBB-AM broth) were used in all operational areas. Direct and indirect contact points and/or operational weak points were the main focus.

Direct contact points involve continuous or frequent contact with beer or beverage. As a result, potential beverage-spoilage organisms may adapt to the beverage and, over time, take on an obligate harmful character. Biofilms in such areas contain predominantly mucigenous acetic acid bacteria. Indirect contact points or weak points without contact with beverages show mainly concentrations or biofilms with ubiquitary slime-forming agents (e.g.

Using UV light to show up weakness in cleaning systems

One of the most important pre-requisites for food processing operations in production of high-quality products in perfect condition is strict compliance with good hygiene practice and a tightly organised quality assurance system. By specifying, executing, achieving compliance as well as monitoring all safety measures or monitoring "critical quality aspects" during the whole production process, the consumer is assured of having food which can be enjoyed without reservation. Modern methods involving preventive measures to avoid mistakes are given priority.

In practice, visual and microbiological checks are used to evaluate the effectiveness of cleaning and disinfection routines. Visual checks suffer oftentimes from the disadvantage that they are not sufficiently accurate. 1). 2). ..

Preservation of brewers yeast Part 2: The influence of preservation on yeast vitality and beer quality

The influence of various yeast preservation methods on vitality and beer quality has been investigated. It was found that no relationship exists between survival rates after preservation and vitality of yeasts during fermentation. This is a convincing argument to support the clear distinction between the concepts of viability and vitality.

After it has been observed that the lyophilisation preservation method was unsuitable due to its negative effects on brewing-related yeast characteristics, the practicable method of partial desiccation of yeasts on filter paper is examined in more detail in terms of its influence on taste and taste stability of beers. However, in the case of weizen beers, the tendency was more in favour of the reference beer.
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Flavour stability starts with malt and in the brewhouse A survey of research results

It is important that all direct and indirect factors are taken into account for improving the flavour stability of pale beers on a sustainable basis. These factors range from processing of barley to the cast wort, to fat oxidation and Strecker degradation. In the main, it is also a question of utilising natural malt-based antioxidants, radical scavengers and LOX inhibitors as well as hop-based inhibitors of fat oxidation. The author highlights the most important aspects, also including recent research results.

Reactions and raw materials - this might be a heading describing the two main influences on flavour stability of a beer. Strecker aldehydes can be determined more simply and in larger quantities in aged beer than aldehydes of fat oxidation such as e.g. trans-2-nonenal.g.g...

Antioxidative potential of beerSignificance for beer quality and nutritional-physiological properties compared to other beverages

For the brewer, an important quality characteristic of beer is taste stability (Back et al., 1997). Dalgliesh (1977) spoke of a taste instability as every beer is subject to a natural staling process. As a result of having special constituents, beers are, however, capable of reducing staling processes which are mainly oxidative in nature. Furthermore, brewers are nowadays in a position to keep beer largely oxygen-free right up to the filling stage. This manifests itself in significantly improved taste stabilities.

The discovery of free radicals in beer (Kaneda et al., 1988) was a further contribution to the staling theory of beer. As a result of endogenous antioxidative activity, beers are in a position to prevent formation of radicals. Production of SO2 can be purposely raised.g.