Ageing and Oaking of Wines with Ultrasound
Wine ageing and oaking contribute heavily to the final taste and quality of wine. Both processes are known to undertake long time, often the maturation process goes over serval years. Ultrasound is a highly efficacious and rapid technology, which intensifies wine maturation and accelerates processes such as the extraction of oak compounds, micro-oxygenation and chemical processe (e.g., polymerization) significantly. With ultrasonication, young wines can be aged within minutes to matured wines with the bouquet of several years of ageing in oak barrels.
Oak-Derived Wine Flavours using Ultrasonic Extraction
Astringency-related phenolic compounds and aromatic compounds both derived from oak wood are transferred extremely rapid when sonication is applied during wine during ageing. Ultrasound accelerated the extraction of oak compounds to a few minutes – compared to several years of traditional barrel ageing of wines.
Oaking of Wine with Ultrasound
For intensified oaking, oak chips or staves are sonicated in wine. The ultrasound waves open and disrupt the cell walls of the wooden material, so that the intracellular compounds such as tannins, phenols, furones, lactones etc. are released by ultrasonic cavitation into the wine. Since ultrasonic oscillation and cavitation create intense turbulences and micro-streaming, the mass transfer between the cell interior and the surrounding solvent is drastically intensified so that the biomolecules (i.e. aroma compounds) are efficient and rapidly released. Since sonication is a purely mechanical treatment it does not add any chemicals to the wine.
Ultrasound – Solely Mechanical Forces
High-intensity, low-frequency ultrasound creates energy-dense conditions, featuring high pressures, temperatures and high shear forces. These physical forces promote the disruption of cell structures in order to release intracellular compounds into the medium. Additionally, ultrasonically-assisted ageing process of wine promotes micro-oxygenation and oxidation processes. Thereby, controlled ultrasonication can positively affect the chemical reactions in the wine. Ultrasonically aged wines reach their quality peak significantly faster than traditionally aged wines. Furthermore, ultrasonically aged wines show a higher preservation level, so that sonicated wine maintains its peak quality for a longer time than the standard ageing process.
Advantages of Ultrasonic Wine Ageing Over Oak Barrel Ageing
Oak barrels are the common, traditional process for wine ageing. In the oak barrels, oxidation takes place in a small amount over a long storage time in the barrel. The storage time for premium wine oven takes several years in is thereby a costly process. During the maturation in oak barrels, the wine produces numerous unique aromas. Besides the long maturation process of years and the related time loss, oak barrels are expensive to purchase and maintain. Undesired microorganisms such as yeast species (e.g., Brettanomyces and Dekkera) may contaminate wine barrels. Yeast spoiled wine is known for poor taste and odour.
Due to these disadvantages of traditional barrel oaking, ultrasonic wine ageing and oaking is a cost-efficient and scientifically proven alternative to traditional ageing in barrels. Ultrasonication shortens the maturation time and improves several quality factors of the wine. Ultrasonication can be applied during various stages of the winemaking process, including maceration, polyphenol extraction, as well as ageing, maturation and oaking. Scientific studies and industrial implementations prove the validity of ultrasonication in winemaking with major improvements in shortened ageing periods and the more efficient production of high quality wines.
Scientific Studies on Ultrasonic Ageing of Wines
An ultrasonic intensity or acoustic energy density level at a relatively moderate level can promote rapid extraction and leaching of phenolics from oak chips into wine, thus potentially increasing the wine flavour and nutritional value within a significantly shortened maturation time. Furthermore, ultrasound treatment is capable to modify the composition of wine rapidly, which is assumed to be due to the effects of acoustic cavitation. Thereby, a high level of acoustic energy density is supposed to promote the ultrasonic modification of wine composition. (cf. Yang et al., 2014)
Similar ageing effects have been reported by Jiménez-Sánchez et al. (2020) for sherry vinegar using oak chips and ultrasound. Ultrasonication reduced the maturation time significantly when compared to traditional maturation.
Ultrasonic Release of Aroma Compounds from Oak
Breniaux and colleagues investigated the effects of high-power ultrasound for cleaning oaken wine barrel and the subsequent release of polyphenolic and other compounds, when the barrels were used after the treatment for wine ageing. Polyphenols and phytochemicals such as ellagitannins, lignin, and aromatic precursors contribute heavily to wine maturation and flavour. Overall, the study showed that ultrasonic treatment gave higher yields of polyphenols and other bioactive compounds within a very short treatment time. For instance, the concentration of furfural was higher in the case of ultrasound treatment at 8 months of ageing and 12 months of ageing, with the concentration increasing between 18.8 and 92.6% compared to alternative steam treatment. For the 5-methylfurfural, the concentration was significantly higher for ultrasonic treatment for barrels of 1 year-old barrels (12 months aged wine) and 2 year-old barrels (2, 8, and 12 months aged wine) with an increase between 20.5 and 97%. Regarding the whisky lactone diastereoisomers, the trans-whisky lactone was significantly higher for 3-year old barrels treated with ultrasonics: after 12 months of ageing, the wine has a concentration at 75.2 ± 5.6 μg/L, resulting in an increase of 46.9% compared to the wine aged in a steam-treated cask. For the concentrations of vanillin and syringaldehyde, values measured in wine were also significantly higher after the ultrasonic treatment. When compared with barrel steam treatment, the total energy consumption was 0.38 kWh for power ultrasound and 3 kWh for aqueous steam, which is 7.89 times lower.
(cf. Breniaux et al., 2021)
Ultrasonically Promoted Chemical Reactions in Wine
During wine ageing, numerous chemical reactions take place. For instance, proanthocyanidin compounds tend to polymerize, condense with anthocyanins, and combine with other polymers, such as proteins and polysaccharides. This condensation reaction with anthocyanins is the main chemical reaction involved in darkening and stabilization of the color of red wine, which changes from a bright red to dark red with brown tones.
Early studies by Masuzawa et al., 2000 already demonstrated that ultrasound promotes the polymerization of the phenolic compounds and increases the polyphenolic content in red wine as the wine matures.
During wine ageing in barrels, hundreds of compounds can be extracted from wood to wine, which directly contributes to the flavour, aroma, and mouth-feel sensations of the final wine. The fibre composition of the oak wood plays an important role in the ageing process, since volatile phenols and phenolic aldehydes from lignin, and furfural compounds from cellulose and hemicelluloses sugar degradation are extracted.
Although the traditional oak-barrel ageing has been extensively employed for centuries, there are still some inherent disadvantages. Firstly, the ageing process in a barrel normally takes from a few months to several years, which is very time-consuming. Secondly, barrels are expensive, take up a lot of space in the winery and need to be replaced with time. Thirdly, as oak casks become older, they may be contaminated by undesirable microorganisms such as yeasts genera Brettanomyces and Dekkera.
Read more about ultrasonic sanitation and cleaning of wine barrels!
Ultrasonic Equipment for Wine Ageing and Maturation
Since several decades, Hielscher Ultrasonics is trusted supplier of high-power, low-frequency ultrasonic processors to the food and beverage industry. Wineries and distilleries have adopted the ultrasonic technology to produce high-quality wines and alcoholic beverages under more efficient conditions, i.e., get high quality results in an accelerated process and under precisely controllable conditions.
Hielscher ultrasonicators are available at any size, from the hand-hold lab device for research and quality control to bench-top and pilot systems for boutique vineyards and mid-size winemakers as well as high-throughput ultrasonicators for large commercial wine producers.
All Hielscher ultrasonic processors feature state-of-the-art technology including digital colour display, sophisticated software, smart settings, automatic data protocolling on integrated SD-card, and browser remote control for precise operation, repeatable and reproducible results, as well as highest user-friendliness. Customers worldwide use Hielscher Ultrasonics technology in wineries and distilleries achieving great results in ageing, oaking and infusing wines and spirits.
Contact us now! Our well-trained and long-time experienced staff will assist you with technical information, recommendations on the ideal ultrasonicator and unbinding quotations!
The table below gives you an indication of the approximate processing capacity of our ultrasonicators:
|Batch Volume||Flow Rate||Recommended Devices|
|1 to 500mL||10 to 200mL/min||UP100H|
|10 to 2000mL||20 to 400mL/min||UP200Ht, UP400St|
|0.1 to 20L||0.2 to 4L/min||UIP2000hdT|
|10 to 100L||2 to 10L/min||UIP4000hdT|
|n.a.||10 to 100L/min||UIP16000|
|n.a.||larger||cluster of UIP16000|
Contact Us! / Ask Us!
Literature / References
- Parthey, Beatrix; Lenk, Matthias; Kleinschmidt, Thomas (2014): Ultraschallbehandlung von Traubenmaische und Wein. Präsentation der Hochschule Anhalt, Mitteldeutsches Institut für Weinforschung, 2014.
- Breniaux, M.;Renault, P.; Ghidossi, R. (2021): Impact of High-Power Ultrasound for Barrel Regeneration on the Extraction of Wood Volatile and Non-Volatile Compounds. Processes 2021, 9, 959.
- Y. Tao, Z. Zhang, D. Sun (2014): Experimental and modeling studies of ultrasound-assisted release of phenolics from oak chips into model wine. Ultrasonics Sonochemistry 21, (2014). 1839–1848.
- Y. Tao, J.F. Garcia, D.W . Sun (2014): Advances in wine aging technologies for enhancing wine quality and accelerating wine aging process. Critical Reviews in Food Science and Nutrition 54, 2014. 817–835.
- Masuzawa, Nobuyoshi; Ohdaira, Etsuzo; Ide, Masao (2000): Effects of Ultrasonic Irradiation on Phenolic Compounds in Wine. Japanese Journal of Applied Physics, 39 (Part 1, No. 5B), 2000. 2978–2979.
- B.K. Tiwari; A. Patras; N. Brunton; P.J. Cullen; C.P. O’Donnell (2010): Effect of ultrasound processing on anthocyanins and color of red grape juice. Ultrasonic Sonochemistry 17(3), 2010. 598–604.