## 3 Results  
### GC-O  
For this study, the GC-O method detection frequency method was utilized. Three panelists carried out duplicate analysis for each aged lambic sample. For each sample, six individual analyses were obtained. The number of panelists who identified the odorant were counted and the odor descriptor was recorded. A total of 21 compounds were identified in all five samples. Compounds were identified based off of their calculated LRI values, mass spectra, and odor descriptors with those of pure compounds. Each compound identified in Table 1 Aroma compounds identified in aging lambic beer using GC-O has been previously reported in lambic beer [7; 12]. A two-way multi variance ANOVA, paired with Tukey's HSD, was run to compare detected compound vs. aged sample, detected compound vs. detected compound, and age vs. age significant. Statistically, differences (\(p\) = 0.005) were seen between the compounds and the age. This was not surprising since there were differences in the number of times the compounds were detected by panelists in different samples. There were a number of instances when a compound would be identified in one sample and not in another. Statistically, differences (\(p\) = 0.03) were also observed between the different age samples. The could easily be explained by the fact that, as lambic beers begin to age, ester compounds usually associated with freshness will start to disappear, while aging compounds like ethyl lactate or aroma metabolites (4-ethylphenol) produced by _Brettanomyces_ during the fermentation process will be at a high enough concentration to be detected. Statistical differences (\(p\) = 0.01) were also observed between compound to compound. When using a GC-O dilution method like CHARM (Combined Hedonic Aroma Response Measurement) and AEDA (Aroma Extraction Dilution Analysis) for the examination of key odorants, a series of dilutions are made usually between eight and twelve dilutions total. Multiple rounds of analysis (sniffing) are required for reliable detection. However, if the GC-O detection frequency method is utilized, a single analysis per sample is required without diluting the sample. The primary flavor and aroma compounds of traditionally brewed beer come from the malt and hops. Lambics utilize several different strains of microbes to make its unique flavor and aroma profile. The aroma and flavor profile of spontaneously fermented or sour beers are defined by their acid profile. The sour aroma and tart flavor come from the acids, while the fruity aromas are esters that are produced by esterification between acids and alcohols. Acetic and lactic acid are the primary two acids that are detected when tasting this beer; however, the panelists were unable to detect acetic and lactic acid by GC-O. The DVB/CAR/PDMS SPME fiber has a useful polarity and absorption characteristics for characterizing and extracting a number of volatile and semi-volatile compounds; however, it does struggle with extracting some groups of compounds like acids. Various yeast metabolites include aromatic and aliphatic alcohols, esters, organic acids, sulfur compounds, and a number of other compounds have been identified in beer. A number of these volatile and semi-volatile compounds have been shown to have a major impact on the flavor profile of a beverage even when presented in low quantities due to their low flavor threshold [17]. The most important flavor compounds in both lambic and other beers are the higher alcohols and esters, organic acids, dimethyl sulfide, and diacetyl; this is very similar to that of American lagers [18; 19]. Among the twenty-one compounds detected, none were identified by everyone. Ethyl hexanoate was the only compound that had the highest detection frequency within the three-month sample. Only four (propanoic acid, 2-methyl-1-butanol, isoamyl alcohol, and decanal) odors were detected by 60% of the assessors.