Energy savings in the brewhouse
Since the energy crisis in the 1970’s there was a steady increase in costs for primary energy. And nowadays everybody knows that these costs have to be reduced in the production process to come to economic products, which the consumer is able to afford. Further, the spoilage of primary energy leads to higher emission rates, which are also due to higher costs and pollution. Therefore the lowering of energy consumption must be seen as a very important factor during the whole process of production. In a brewery the brewhouse is the most energy consuming part – with mashing, heating and boiling of the wort. But it is not only the thermal energy, electric energy has to be considered too. For example, German breweries did have lowered the specific fuel heat consumption by around 40 % from 1980 to 1997. The electric energy consumption kept nearly the same in this time. But this can be
explained by the fact that the thermal energy saving potential in the brewhouse is much higher than the electric energy saving potential. To give some values, German breweries in the range of 300.000 hl to 500.000 hl of sales beer (SB) a year have a whole specific electric energy consumption of 7 – 12 kWh/hl SB and a whole specific thermal energy consumption of 90 – 150 MJ (≡ 25 – 42kWh)/hl SB. From this very high value of thermal energy the brewhouse can take part in up to 65 %, so that you come to a very high energy saving potential (11, 21).
Evaluation and utilization of spent grains
Spent grains are produced by the extraction of malt. By the extraction of malt the
soluble parts are dissolved in water, for example starch and Sow molecular sugars.
The non-soluble parts are the spent grains The brewery spent grains {BSG} are the
dominating by-product in the brewery, besides hat trub, malt dust, etc. in beer
production, about 18 - 20 kg of wet grains are produced per hl of saleable product
Isomerized Hops
In former times hops are used in an unprocessed form (whole hop cones). But there are
many problems associated with this kind of hops. Like for example:
• the handling even if it is pressed into bales there is only a bulk density of
100 – 150 kg/m3, which leads to high spaces in storage or for transport
• besides this lightness, it is very sticky, so that it is impossible to add it into the kettle automatically
• the heterogeneity due to the picking period and variety leads to variable bitterness in the final beer
• or the stability during storage which is endangered by microbiological action and
oxidation
Therefore the hop products were invented to reduce or even eliminate such negative
aspects. These products became available in the late 50’s, early 60’s (7). Nowadays the main intention is to reduce the costs in every business or company. In a brewery this aim can be reached effectively with the following factors:
• the progress of automation
• lowering the energy consumption
• and by a good utilization of the raw materials
Quality control in the brewhouse
The quality control in the brewhouse is a very important thing. Today it is talked
more about quality management than about quality control. During the last years
there has developed more and more competition, specifically in the point of shelf
life. To guarantee a long shelf life there has to be done some controls on the
different raw materials, as well as during and after the different proceeding steps.
The following picture shows the properties where samples can be taken during
the production of wort.
