Session Chair:
David De Schutter (Innovation & Technology Development Director Europe, AB Inbev, BE)
The use of wood alternatives for beer flavouring
By Gert De Rouck et al., KU Leuven
Wood barrel ageing of beer is very popular nowadays. However, need for space – unpredictable outcome – lots of manual work,.. are important drawbacks for up-scaled production. Chips, cubes, staves, powder, wood extracts as alternatives are available. The impact on the wood flavour is to expect although to what extent? No knowledge is present on the physico-chemical and the microbial quality of the final beer.In this study, 260 beers, brewed in our pilot brewery, varies in wood product (from chips to extract), origin (French/American), concentration, contact time, re-use, batch-to-batch difference, original extract, and yeast. Wood flavour is determined via HS-SPME-CGC-MS and sensory profiling. The impact on colloidal stability and foam stability is measured and microbiology control was performed.French oak is more spicy/pungent compared to American Oak (malate-sweet), contact time varies from 2-3 weeks when 3g/l is used (but product depending). French oak has a positive impact on colloidal stability, but all wood is negative for foam stability. Different batches resulted in equal beers. Higher alcohol results in increased flavour extraction. More conclusions will be presented.
Lager barrel aging. Evolution of key physical-chemical parameters
By Igor Oyarbide Sangroniz and Alejo Giron Gonzalez, Grupo Mahou-San Miguel
Barrel aging of beer has become a worldwide trend in the last couple of decades among craft brewers. Apart from existing traditional Old World beer wood aging, new styles have adopted the use of oak barrels in the production process, normally using ex-spirits barrels for stronger versions of ale styles. Yet, barrel aging of lagers still remains uncommon. This study focuses on investigating how barrel aging affects common parameters of lager beer. Original extract, ADF alcohol, color, pH, bitterness and VDK among others were monitored during the barrel aging process. Microbiological analyses were performed as well to determine the presence of possible yeast and bacteria contaminants. The results and techniques employed will be discussed to help brewers understand the challenges of barrel aging and how beer evolves during its maturation process.
Flavor evaluation of beer with the addition of oak during the brewing process
By Mayu Ohata et al., Sapporo Breweries Ltd.
Oak barrel is commonly used for aging and flavoring wine and whiskey. Some craft brewers have attempted to produce barrel-aged beer. Oak wood imparts a specific flavor to the finished beer, such as vanilla, smoky, spicy, and roasty. However, barrel-aging method has several disadvantages because of the need for barrels and the time-consuming process and so on. In this study, we investigated the process of beer making by adding oak during the brewing process. Oak addition is performed at the time of mashing, primary fermentation, secondary fermentation, and maturation. In previous studies, the oak material was sometimes added after fermentation but not before fermentation. We evaluated the finished beer by analyzing the oak-derived compounds and by sensory evaluation. The results revealed that aroma of oak was imparted to the beer, regardless of the oak addition timing and within a shorter time than that in the case of barrel aging. Some differences in flavor characteristics were confirmed between the finished beers. These results suggested that the addition of oak during the brewing process is effective in imparting the characteristic flavor and aroma to the finished beer.