Department of Viticulture and Enology, University of California, Davis, One Shields Avenue, CA, USA.
School of Biotechnology, Assumption University, Bangkok, Thailand.
J Sci Food Agric. 2019 Jan 30;99(2):805-815. doi: 10.1002/jsfa.9249. Epub 2018 Sep 3.
Cold soak is a prefermentative maceration technique believed to enhance grape skin extraction. Studies show variable results depending on cold soak and winemaking conditions. To investigate the effect of cold soak more fully, systematic and highly reproducible Cabernet Sauvignon fermentations with increasing cold-soak durations were performed.
Phenolic extraction during cold soak and fermentation showed significant differences among all treatments for monitored phenolics at the end of the cold soak. At the end of alcoholic fermentation only gallic acid, (-)-epicatechin, and the flavonols were significant, and only (-)-epicatechin was significant after bottle ageing. Descriptive analysis of the bottled wines showed that the 4- and 7-day treatments were significantly higher in caramelized/vanilla/browned flavor compared to the 1-day treatment and lower levels of bitterness were observed up to 2 days of cold soak. While oligosaccharide content increased with increasing cold-soak duration, differences were not large enough to result in sensory differences.
While increased cold soak duration led to differences in phenolic extraction during early fermentation, these differences did not last through to the end product. Thus, under the conditions of this study, cold-soak duration had little overall impact on Cabernet Sauvignon wine composition and style. © 2018 Society of Chemical Industry.
冷浸渍是一种预浸渍技术，被认为可以提高葡萄皮的提取率。研究表明，冷浸渍和酿酒条件的不同会导致结果的差异。为了更全面地研究冷浸渍的效果，我们进行了一系列系统且高度可重复的赤霞珠发酵实验，其中增加了冷浸渍的持续时间。
冷浸渍和发酵过程中的酚类物质提取在所有处理中均存在显著差异，尤其是在冷浸渍结束时监测到的酚类物质。在酒精发酵结束时，只有没食子酸、（-）-儿茶素和黄烷醇类物质具有显著性，而在瓶陈结束时只有（-）-儿茶素具有显著性。对瓶装葡萄酒的描述性分析表明，与 1 天处理相比，4 天和 7 天处理的焦糖/香草/烤面包风味明显更高，苦味水平在冷浸渍 2 天内下降。虽然寡糖含量随冷浸渍时间的增加而增加，但差异不足以导致感官差异。
虽然冷浸渍时间的增加导致了早期发酵过程中酚类物质提取的差异，但这些差异并没有持续到最终产品。因此，在本研究的条件下，冷浸渍时间对赤霞珠葡萄酒的成分和风格影响不大。 © 2018 英国化学学会。
