| The mechanism and influencing factors of hydrogen bonding, relationship between hydrogen bonding intensity with taste and brewing process were investigated primarily according to the hydrogen bonding association of alcohol system in this paper. A steady configuration was simulated by Gaussian03 software and existed in 3.3 %,4.5 %,60 % of ethanol in ethanol-water system. The viscidity and partial mol volume were studied. Hydrogen bonding intensity augmented gradually within 0-60 % of ethanol. Intensity was weaken gradually when the concentration overed 60 % and arravied the maximum at 60 % and the ratio of ethanol to water was 1:2.Hydrogen bonding was easier to be detected by NMR in beer system. Experimental error of NMR was 0.002 ppm and 1 % of ethanol was reflected with the per-changes of 0.005-0.009 ppm. The range of proton chemical shift was 4.896-4.935 ppm as the alcohol degree less than 5 %. The hydrogen bonding was formed by hydroxyl of ethanol and water and had -23 %～-40 % of influence by other substance.Influence of temperature, pH, organic acid, ethanol ester and salt on hydrogen bonding of ethanol-water were studied by Plackett-Burman design in this paper. The proton chemical shift was minishing with temperature augmenting but the influence of pH on hydrogen bonding was not distinctness. The relativity order of organic acid was malic acid, lactic acid, pyruvic, acetic acid, tartaric acid, citric acid and amber acid. The determination coefficient was 95.93 % and reliability of the first three was 80 %. The relativity order of ethanol ester was isobutanol,β-phenylethyl alcohol, ethyl acetate, propanol, isoamyl acetate, isoamyl alcohol. The determination coefficient was 89.09 % and reliability of the first three was 80 %. The relativity order of salt was KCl, NaCl and MgSO4, MgCl2,Na2SO4,K2SO4,CaCl2. The determination coefficient was 97.91 % and reliability of the first three was 85 %.The 25 main parameters were analyzed for 35 finished product purchased beer. Alcohol concentration was the primary factor and the coefficient with hydrogen bond intensity was 0.629 by relativity analysis. Hydrogen bond was influenced positively by wort original gravity, isobutanol, Cl-, K+, pyruvic acid and lactic acid but was influenced negative by SO42-, Na+. Alcohol was the most important factor that impact on hydrogen bonding association for beer by the principal component analysis and regression analysis. The model of hydrogen bonding association intensity was established by multiple non-linear regression analysis. The hydrogen bonding association intensity (chemical shift) = 4.916 +0.003[E] -0.005[P]+5.031E-8[K2] + 1.558E-5[K×P]+2.369E-5[E2P]-2.207E-5[P3]+2.244E-8[K3]-5.947E-7[K2P]-2.037E-5[E2K]+ 4.276E-6[P2K]. The decision coefficient (R2) was 0.736 with P 0.001, the equation have a better response for relationship between the variables and hydrogen bonding intensity and was very markedness. The error was -3.06~0.60 % by validated, which proving the multiple non-linearity model can simulate the hydrogen bonding association in beer. Hydrogen bonding has a positivety linearity relation with mellow-bold and a negative curve relation with sour taste.The chemical shift of ordinary brewing was higher than the dilution brewing beer at the same original wort degree. The concentration of ethanol ester, organic acid in ordinary brewing beer was higher than in dilution brewing beer. The hydroxyl proton chemical shift and concentration of flavor substance were gradually degression along with the increase of dilution ratio. The 8 oP was the better dilution craft for 13 oP high gravity beer and the better dilution ratio was about 63 %. The hydrogen bonding association came through the course of balance–enhance–balance–enhance–top–weaken–balance during the hydrate of beer and achieved the top at 14 h. The optimal hydrate time was 14 h for 63 % dilution ratio of 8 oP beer and the changes of hydrogen bonding association can well reflected the flavor and taste for beer.
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