Influence Of Beer Brewing Procecdure On Volatile Flavor Compounds

Wort could produce a series of metabolic by-products via fermentation,which make the unique taste of beer flavor substances.The flavor substances directly affect the quality of beer products.It is important to choose and control the ingredients,yeasts,saccharification and fermentation processes.Effects of yeast-related factors such as yeast generation,batch,yeast species,pitching rate,propagation 5 flocculation and fermentation conditions on beer volatile components were studied under production scale fermentation.The results showed that the pitching rate didn't have significant effect on volatile components,but yeast generation,batch,yeast species and flocculation have significant effect on volatile components,especially for acetaldehyde.Different yeast species have different volatile components,so we could choose appropriate.yeast strain according to their special volatile components.Optimization yeast propagation condition and using zinc sulfate in yeast propagation are benefit to yeast performance and the quantities of beer volatile components.Here,saccharification and fermentation process of beer flavor substances were analyzed,including the malt proportion,saccharification temperature,wort oxygenation,fermentation temperature,etc.The results showed that the affect of saccharification process on beer flavor was not significant,the influence of improving the original wort concentration is conducive to the formation of esters and the reduction of alcohol ester ratio.However,the DMS scavenging were significantly affected by different boiling methods,and the removal rate of DMS was significantly high using dynamic low pressure boiling.The content of volatile ester will beincreads by reducing the oxygen amount,which can be helpful for the improvement offermentation flavor.For the adjustment of fermentation process,reduction of main fermentation temperatureis conductive to decrease the yield of the high alcohol and the alcohol ester ratio,which will also cause the rise of acetaldehyde.Prolonged reduction reaction is beneficial for the decrease of acetaldehyde,but the main influence on flavor is yeast.The effect of tank volume and tank pressure on flavor compounds is not significant.Yeast is significant impact to volatile flavor compounds.Hence,it is conducive to improve the beer quality by strengthening the management and use of yeast,timely monitoring the stability of beer flavor compounds.