During maceration, red wine develops its phenolic and aromatic profile. The outcome of maceration depends on multiple factors including fruit composition, chemical processes and winemaking techniques. How do common winemaking techniques affect the chemical and sensory properties of wine? Federico Casassa presented on this topic at our 2016 Vintage Report conference in Paso Robles, CA.
Winemaking techniques explored in the talk include cold soak, extended maceration, saignee and the addition of whole clusters and stems. In the cold soak method, winemakers chill the must before fermentation using refrigeration or ice water. In the saignee method, winemakers “bleed off” a small percentage of the must to produce a more concentrated juice.
Cold soak practitioners often cite improved aroma and flavors as the key motivation for this winemaking technique. Interestingly, Casassa’s 2014 paper shows that cold soak has negligible effects on aroma, bitterness, astringency, and body of the wines. In another study, the traditional external refrigeration method even showed negative impact on anthocyanin, phenolic content and color saturation.
When combined with other techniques, however, the cold soak method leads to interesting results. Combining coal soak with the whole cluster method increases floral and fruity notes for the wine, while combination with the whole stem method produces vegetative notes.
Cofermentation is another frequently used technique with the purpose of improving mouthfeel and enhancing aroma profile. In 2015, Casassa experimented with cofermenting Syrah with different quantities of Viognier grapes. This experiment did not produce improvements in phenolic contents or color stability of the wine.
Casassa’s 2016 paper studies the effects of extended maceration and saignee methods on tannin composition and extraction under regulated deficit irrigation for Cabernet Sauvignon grapes. Both extended maceration and saignee wines show better tannin extraction relative to wines made under standard maceration. In terms of color saturation, however, extended maceration leads to lower anthocyanins while saignee produces higher anthocyanin and concentration of color pigments.
The use of different techniques or combination of techniques has negligible to significant impacts on wine sensory properties and phenolic contents. Fruition Sciences will continue to monitor latest research results and share with you through this blog as well as through our signature Vintage Report conferences.
The Vintage Report brings together scientists, winemakers and industry leaders from all over the world to produce a one-day seminar that brings together open minds within the industry to discuss the previous year’s harvest in light of the most recent scientific findings and newly available data. Our biggest impact is asking the question: how can we leverage what we learned this year to improve vineyard practices and wine quality? Check it out at https://www.vintagereport.com.