This week AEB USA's Scientific Advisor Federico Tondini, PhD, is discussing an article published in the Journal of the Science of Food and Agriculture:
Lerno, Larry A., et al. (2018) "Impact of cold soak duration on Cabernet Sauvignon fermentation and phenolic composition."
Department of Viticulture and Enology, University of California, Davis, CA 95616 This article investigates the effects of increasing Cold Soak duration on phenolic extraction, sensory properties and polysaccharides on resulting wines, to provide a better tool for color and tannin extraction.
Results:The experiment showed that 4-7 day Cold Soak treatment having the greatest anthocyanin extraction concentration, while tannins extraction was relatively low during Cold Soak, with most of the extraction occurring at the beginning of alcoholic fermentation. In these conditions, the extracted color risk to precipitate out of solution because it cannot polymerize, and therefore, be protected.
A tannin for color stabilization specifically design for cold soak. It’s a blend of ellagic tannins from oak and proanthocyanidinic tannins from grapes which are activated with an ethanal bridge. Ethanal bridges is greatly responsible for color stabilization and tannin polymerization even is absence of ethanol, and then suited for pre-fermentative maceration.
AEB R&D labs also conducted a detailed analysis to formulate different tannins blends best targeted specific grape varieties with similar color profile (similar anthocyanins composition).
AEB VARIETAL TANNINS!!! • Fermotan CB for Cabernet, Merlot, Teroldego, Montepulciano, Barbera, Syrah. • Fermotan AG: for Aglianico, Nero d’Avola, Primitivo, Zinfandel, Malbec, Tempranillo. • Fermotan SG: for Sangiovese and Pinot Noir.
The results also indicate there were no significant differences among treatments in tannin composition except that the longer Cold Soak duration could potentially favor seed extraction. The 4- and 7-day Cold Soak wines exhibited significantly higher values in caramelized/vanilla/browned flavor.
AEB solutions are PROTAN PEEL and PROTAN RAISIN: proanthocyanidins tannin from grape skins. They add a velvety smooth structure, boosting the body and mid-palate of the wine.
AEB also offers a vast range of ellagic tannin (ELLEGITAN BARRIQUE), which can impart to the wine desired flavours in different combination, depending of the type and toast of the oak (i.e. caramel, almonds, woody, spices, cloves, coconut, vanilla, berries).
Finally, the abundance of polysaccharides generally increased up to 7- day Cold Soak and then decreased with the 10-day Cold Soak, but no significant impact on the mouthfeel were detected in the sensory testing.
If you find yourself in the situation where you want to modulate the astringency perception, increasing the sweetness sensation and body, try AEB polysaccharides.
AEB provides polysaccharides from different sources: yeast derived, which simulate sur-lies and bâtonnage techniques, and gum Arabic (plant derived-Acacia) with different molecular weight and structure to obtain different sensory properties, ranging from aroma enhancing and protection to increased mouthfeel and sweetness.