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62 p r a c t i c a l w i n e r y & v i n e ya r d O c t O B e r 2 0 1 4 w i n e M A K i n G phenols and vanillin. The levels of oak volatile compounds extracted were quan- titatively different depending on contact time and type of toast (Figure 1). Figure 1 shows that furfural and 5-methylfurfural reached maximum concentration either at three or six months of aging. In all samples furfural content was exhausted after 12 months. "Noisette" was toasted two hours lon- ger than medium toast (MT) staves and produced more furfural and methyl-fur- fural. "Special" (oak wood heated using medium temperature with watering) produced almost double the methyl-fur- fural compared to MT. Hence, along with the length of toasting time, the water- ing process has an important impact on furanic compounds. Regarding phenolic alcohols, the maxi- mum extraction of guaiacol occurred Table II: Pearson correla ons between chemical and sensory data. Marked correla ons are significant at p <0.05. Vanilla Woody Spicy Sweetness Astringency Bi erness Elagitannins -0.290 (NS) -0.085 (NS) -0.278 (NS) -0.180 (NS) 0.828*** 0.607*** Furfural -0.352* 0.011 (NS) -0.437* -0.315 (NS) 0.430* 0.393* Methyl- -0.034 (NS) 0.050 (NS) -0.139 (NS) 0.114 (NS) 0.403* 0.264 (NS) Furfural Trans-WL 0.351* 0.582** 0.388* 0.353* 0.166 (NS) 0.196 (NS) Cis-WL 0.445* 0.636*** 0.458** 0.537** 0.056 (NS) 0.024 (NS) Ra o 0.502** 0.385* 0.417* 0.758*** -0.327 (NS) -0.525** Guaiacol 0.065 (NS) -0.035 (NS) 0.025 (NS) -0.158 (NS) -0.431* -0.207 (NS) Methyl- 0.484* 0.396* 0.420* 0.467 (NS) -0.658*** -0.546** Guaiacol Eugenol 0.428* 0.636** 0.462** 0.314* 0.139 (NS) 0.154 (NS) Syringol 0.028 (NS) -0.108 (NS) 0.004 (NS) -0.169 (NS) -0.526** -0.92 (NS) Syringaldeyde 0.684 (NS) 0.691*** 0.601*** 0.547** -0.382* -0.373* Vanillin 0.595*** 0.657*** 0.509** 0.551** -0.212 (NS) -0.279 NS) NS = not significant difference; *, **, *** Significant differences at 5%, 1% and 0.1% respec vely Table ii: a P value is the probability of obtaining the observed effect (or larger) under a 'null hypothesis,' which in the context of cochrane reviews is either an assumption of 'no effect of the intervention' or 'no differences in the effect of intervention between studies' (no heterogeneity). Thus, a P value that is very small indicates that the observed effect is very unlikely to have arisen purely by chance, and therefore provides evidence against the null hypothesis. in our case we were evaluating the toasting effect and the p values indicate the importance. it has been common practice to interpret a P value by examining whether it is smaller than particular threshold values. in particular, P values less than 0.05 are often reported as "statistically significant," and interpreted as being small enough to justify rejection of the null hypothesis. however, the 0.05 threshold is an arbitrary one that became commonly used in medical and psychological research largely because P values were determined by comparing the test statistic against tabulations of specific percentage points of statistical distributions. So good you can taste it. 800.367.8383 ■ WesternSquare.com