Abstract Beer is a product with a long tradition and is produced today by both artisanal op-erators and large breweries. The malt needed for this process is produced from barley in the malthouse and delivered to the brewery's area for incoming raw mate-rials. In the brewhouse the malt is turned into wort by a combination of mashing, lautering, boiling, and cool-ing. In the fermenting cellar the wort ferments as yeast is added to the green beer, which needs to mature in the storage cellar before it can finally be bottled after a last filtering.

The tradition behind beer brewing Beer brewing is a highly traditional form of craftsmanship whose core processes have survived to the present day: water, malt, and hops are mixed together, with the addition of yeast bringing about certain biochemical changes. These days, however, these processes are largely automated. Given its long history (the Sumerians were brewing some kind of "original" beer around 4000 BC), beer has become something of a cultural artifact. Germany has a (Bavarian) purity law dating back to 1516. Who is involved in beer production? The beer market is populated by both large industrial brew-eries and small artisanal operators. From the barley to the time the beer is ready to drink, production is divided into three main areas:

• Malthouse • Beer manufacture (area for incoming raw materials,

brewhouse, fermenting and storage cellar) • Bottling and packaging What happens in the malthouse? In the malthouse, grains (mainly barley) are turned into malt. This involves soaking the barley in water until it germi-nates and forms enzymes (green malt). Germination stops once sufficient progress has been made and then the drying process starts, which produces what is known as "kilned malt". The kilned malt gives the malt, and therefore the beer, much of its taste (the "beer's soul"), which explains the particularly high quality demands placed upon it. Malthous-es tend to be free-standing enterprises which operate inde-pendently of the breweries.

Sectors: Food & Beverage – Basics – Beer production

Industry Learning Program

The most important points in brief

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Industry Learning Program – The most important points in brief Sectors: Food & Beverage – Basics – Beer production

What happens at the area for incoming raw materials? The kilned malt is eventually delivered to the area for in-coming raw materials at the brewery and stored in large malt silos. Depending on the type of beer and the analytical values (including friability and water/protein content), the amount of malt required for production purposes is taken from the silos. The malt is ground before it reaches the brewhouse, i.e. the cross-section of the grain is reduced so a larger surface area is available to the enzymes.

[Page 8] What happens in the brewhouse? In the brewhouse the wort is extracted from the ground malt. This involves moving the malt or wort from the mash tun, through the lauter tun and wort kettle, and eventually into the whirlpool. In the mash tun the barley grist is first mixed with water (mashing in). The mixture is then heated in stages, pausing at certain temperatures in order to activate the various en-zymes. This causes maltose and amino acids to form, which provide the basis for the later fermentation phase. When it is ready, the mash is pumped into the lauter tun. The 2-stage lautering process takes place here:

1. The brewer's grain is removed and the extra-rich first wort is drawn off.

2. The caked, spent grain is broken up and watered (sparging) so that the second wort, which is weaker in extract, drains from the claryfying vat.

The wort gained as a result is then boiled in the wort kettle. Bitter hops are added at the start of the boiling process, giving the wort a bitter taste and helping it keep for longer. The aromatic hops added at the end of the boiling process further refine the taste of the wort. The cumulative effect of boiling is to sterilize the wort, remove any unwanted aro-matic material, and set the original wort level. The next step separates the original wort from the hot (or 'coarse') trub. This hot trub is generated when the wort kettle is heated and must be removed so it does not inter-fere with the subsequent fermentation. Removal occurs by pumping the hot wort into the whirlpool. The centripetal force causes the trub to settle on the floor of the pool. Finally, the pure wort is cooled in the wort cellar using plate coolers and tubular coolers.

What happens in the fermenting and storage cellar? In the fermenting and storage cellar, the sugar content is fermented into alcohol. The main fermentation process starts when yeast is added (pitching) to the cold wort and ends when the mixture is pumped into the storage cellar (transferal). The sugar is broken down into alcohol and CO2 during fermentation, creating what is known as green beer. The substances responsible for the smell and taste are formed during this time, as well as various residues. These are siphoned off before the transferal phase.

[Page 16] The green beer is not yet ready to drink. It still needs to mature for one to four weeks in the storage cellar. The un-wanted taste associated with the green beer fades away during this process. Secondary fermentation occurs at the same time, i.e. the fermentation of the residual sugar in the green beer. In addition, any excess yeast and turbid materi-als sediment are precipitated in the storage tank. More CO2 is generated, which both carbonates the drink and removes any by-products. Finally, the beer is filtered one last time to remove the re-maining residues (mainly yeast), improve product life, and make the taste more stable. Both Kieselguhr and PVPP filtration can be used.

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© Siemens AG 2012 2 / 3

Industry Learning Program – The most important points in brief Sectors: Food & Beverage – Basics – Beer production

What can Siemens offer the sector? Siemens is helping the sector make manufacturing pro-cesses more flexible and economical though a consistent approach to automation: from incoming materials to out-going products and from production up to the ERP level. Our range includes standardized products, intelligent sys-tems, and even customized services. As a long-standing partner of the brewing industry over many years, we have the right offer for any kind of brewing plant. One example is our BRAUMAT process control system, specially designed for beer manufacture.

For more information on our products, systems, and ser-vices, please visit http://www.industry.siemens.com/verticals/global/en/food-beverage/beverage-industry/Pages/Default.aspx

© Siemens AG 2012 3 / 3