Study On The Flavor Characteristics Of Dry-Hopping Beer

This article selects the both bitter and aroma hops,adopt the method of the top fermentation,study the effect on beer flavor characteristics of dry hopping,through these three aspects from hops adding process,the amount of adding hops and main fermentation temperature of dry-hopping beer.We study the flavor characteristics of beer from adding hops process.We designed the experiment as follows: added hops during wort boiling,added dry-hopping when wort in whirlpool,and added hops during the main fermentation,from the three hops adding technology with top fermented beer brewing,According to the different amount of the hops added,to the effect of dry-hopping beer flavor characteristics: using 0 kg/h L,0.1 kg/h L,0.2 kg/h L,0.3 kg/h L,0.4 kg/h L hops added weight gradient with top fermented beer brewing.For the fermentation temperature of dry-hopping beer,we setted the fermentation temperature in 15 ?,20 ? and 25 ?,with this three temperature gradient dry-hopping beer brewing test.To detect the total acid,color of beer,bitter taste,total polyphenols,aromatic substances,and sensory evaluation.Through experiments,we come to the conclusion that: different hops added process had little effect on total acid,but the effect larger on color and bitter matter,the beer with add hop during boiling,bitterness is the highest,the dry-hopping beer bitter matter was smaller,and the effect of total polyphenols did not find the rules,Different hops added process of beer mainly effect on the hop aroma for flavor.Compounds isoamylol alcohol content of stem dry-hop beer is low,and ester aroma is rich,not easy to cause after drinking dizzy feeling.Therefore,it is a safe way to brew that use the craft brewing method with dry-hopping.Different hops added quantity have the little effect on beer total acid,with the more hops added,the colour of beer more deeply;And with hops added quantity increased;the beer bitter quality has first increased then reduced,0.3 kg/h L reached highest value;with hops added increased,the total polyp Henol gradually increased then slightly reduced,this effect of different hops added on bitter is similar;some higher alcohol is gradually reduced;with hops added increased,most of hops terpene is increased rose trend,The main odorant Linalool is increased as the amount of hops added their relative percentage increase.The total acids increased with the fermentation temperature,beer color change erratically,color change little,but hace the great influence on the bitter principles,bitter principles with the main fermentation temperature increased,the bitter quality decrease.the effects on total polyp Henols of different main fermentation temperature is significantly,with the main fermentation temperature increases,total polyp Henols increase.The aroma of the samples tested are basically same,slight differences on the peak and the peak area,the higher main fermentation temperature,the higher alcohol content.Through the sensory,we came to the conclusion:taste best when the fermented temperature is 20 ?,especially the hop aroma and ester outstanding,have the fruit,citrus fragrance,bitterness and the sense of dizziness is not strong;the beer of 25?fermentation is mainly strong bitter taste with the bitterness lasted a long time and dizzy feeling strong.The beer with fermentation of 15? makes a fresh hop aroma.Research the aroma substances of dry-hopping beer in the process of storage,concluded that the dry hopping beer compared with the traditional "light" beer,the aroma substances more rich,such as fruity aroma,flowers,floral,citrus,etc.dry-hoping beer aroma substances are abundant,but with the disadvantage of poorer stability.The flavor characteristics of dry hopping beer change without laws,and the repeatability is difficult to achieve.