Napa, Calif.—Oak Solutions Group announced Glenn Jeffries is the company’s new tru/tan technical sales engineer focused on the company's line of enological tannin products. Jeffries has more than 15 years of experience as a chemist for Analytical Sciences in Petaluma, Calif., where he focused on chemical analysis, extractions and field sampling. “Since tannins involve one of the most complex areas of chemistry, we have carefully assembled a team to support the intricacies of this field,” said Kyle Sullivan, Oak Solutions Group’s director of sales.