Controlled trials were conducted in during the 2020 harvest in California, Washington Virginia, New Jersey, Pennsylvania and New York. Nine trial comparisons were evaluated for sensory characteristics and phenolic profiles. Participants provided assessments of operations experiences.
Accentuated Cut Edges is a brainchild of Dr. Richard Smart who conceived the simple idea that skins would extract quicker if fragmented in such a way as to not abrade the seeds. Color and flavor extraction in conventionally crushed grapes does not occur through the outer wax cuticle and proceeds slowly through the pectin-coated inner surface. The exception is the rapid extraction that takes place along the cut edge. This is a minor proportion of extraction because the edge is short and distant from most of the skin’s vacuoles. Smart’s insight was to chop the skins into 8-10 fragments to accelerate extraction.
Initial trials were performed by Dr. Angela Sparrow at the University of Tasmania in 2017 using a stick blender on half-ton bin trials. Engineers at Della Toffola’s research and development facility in Treviso, Italy perfected an automated in-line device in 2018, dubbed DTMA and offered in three low-cost sizes for 10-12, 20-24, and 40-48 metric tons per hour. Preliminary trials were conducted in California, Italy and Australia in 2019. The American trial on which this presentation reports constitutes the first large-scale intensive investigation of the technology.
It is widely held that early extraction of monomeric anthocyanins reduces tannin polymer length, resulting in smaller colloids with greater surface area, more refined texture and greater aromatic integration. Besides the sensory advantages, the DTMA offers the option to press in as early as three days. These wines have brighter red fruit and smoother tannins and thus can be released earlier.