Kvasny Prumysl, 2013 (vol. 59), issue 4
Determination of short chain fatty acids isomers, the sensory active products of hops aging, in beer.Peer-reviewed article
Jiří ČULÍK, Tomáš HORÁK, Martin SLABÝ, Pavel ČEJKA, Jana OLŠOVSKÁ
Kvasny Prum. 2013; 59(4): 86-90 | DOI: 10.18832/kp2013008 
Important products of hop aging are the C4 and C5 isomers of short chain fatty acids; namely 2-methyl propionic acid (isobutyric acid), 2-methyl butyric acid and 3-methyl butyric acid (isovaleric acid). These acids are sensory active and moreover, after the esterification during beer production they can provide further sensory active compounds contributing to a stale aftertaste. In the framework of this study a sufficiently sensitive and selective method for the determination of these substances in beer was developed. This method is based on the isolation of the short chain fatty acids and their isomers by means of solid phase extraction (SPE) and...
The evaluation of α- and β- bitter acid contents of Czech and Moravian hops from the 2012 harvest.Peer-reviewed article
Alexandr MIKYŠKA, Marie JURKOVÁ
Kvasny Prum. 2013; 59(4): 92-99 | DOI: 10.18832/kp2013009
The contents of α- and β- bitter acids from hops harvested in the Czech Republic in 2012 have been evaluated. The sampling was done in all three growing areas - Žatec (77.8% of the hop yard areas in the Czech Republic), Úštěk (10.8%) and Tršice (11.5%). The Saaz variety (ŽPČ) was cultivated on 87.2% of the harvest areas, the Sládek variety on 5.5%, Premiant variety on 5.2% and the Agnus variety on 1.2% of the harvest areas. The hops were analyzed in accordance with the Analytica-EBC, method 7.7 (HPLC) and all results are given in weight % in dry matter. The average value for α-bitter acids in the Saaz variety in the Czech Republic was...
Prediction of beer colloidal haze formation.Peer-reviewed article
Blanka KOTLÍKOVÁ, Lukáš JELÍNEK, Marcel KARABÍN, Pavel DOSTÁLEK
Kvasny Prum. 2013; 59(4): 100-104 | DOI: 10.18832/kp2013010
Like all of foods, beer suffers from a limited shelf life, which is closely related to the colloidal stability. Due to the increasing demand for rather a lasting products, breweries are forced to use a variety of stability-extending agents. Today, there is a number of methods that can predict a minimum shelf life. These methods are called forcing and precipitation tests. Forcing tests accelerate the ageing of beer through alternation of high and low temperature, resulting in earlier formation of colloidal haze. Precipitation tests can detect the content of haze-active precursors in beer, thus predicting its shelf life.Like all of foods, beer suffers...
Fulnek.Peer-reviewed article
Milan STAREC
Kvasny Prum. 2013; 59(4): 105-110 | DOI: 10.18832/kp2013011
The Moravian town of Fulnek is situated on the Moravian-Silesian border at "Goose creek" in the current county of Novy Jicin. The city with the majority of the German population was fatally hit during the Second World War bombing. The first mention of brewing dates back to 1413, when the city was given the right of "brews and mile". During 14th and 15th century, 56 Fulnek's brewers had disputes with reeves of surrounding villages, who brewed their own beer. In 16th century these beer brewing rights disputes grew into a conflict between the city, the nobility and the Augustinian monastery. After the Thirty Years' War the manor brewery was not restored,...