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May 2018 WINES&VINES 71 PRACTICAL WINERY & VINEYARD GRAPEGROWING Differences in storage temperature of only 5.5° F (3˚ C) such as 15˚ C vs 18˚ C or 59° F compared to 64.5° F could have a massive impact on thiol preservation. The cost of refrig- eration should be considered and a workable compromise of 50° to 53.5° F (10-12˚ C) has been identified. 2 Temperature logging during exports should be considered to ensure pres- ervation of all aroma compounds and espe- cially the thiols. It might be worth the cost and effort to ensure the transport temperature and condition is of a certain standard to guarantee better preservation. Interaction with other wine components The Top 10 Sauvignon Blanc competition, pre- sented by the Sauvignon Blanc Interest Group of South Africa and sponsored by First National Bank, is the country's foremost platform for Sauvignon Blanc producers to showcase and benchmark their wines. The ten selected 2015 wines were subjected to various chemical analy- ses including volatile thiol and methoxypyr- azine, while the sensory profile of each wine was determined using projective mapping. Results from the top 10 2015 winners showed great diversity in wine styles: from fresh and fruity to green and even wooded wines and volatile thiol concentration in these wines ranged from less than 10 ng/L to 547 ng/L for 3MHA; while 3MH concentrations ranged from 328 ng/L to 1,638 ng/L. These values are much lower than the maximum values determined by Vinlab for 2015 which ranged from less than 10 ng/L to 2,440 ng/L for 3MHA and 29 ng/L to 4,140 ng/L for 3MH. The diversity of wine styles chosen as com- petition winners, shows great complexity in quality South African Sauvignon Blanc wines. The contribution of other aroma compounds in these wines should not be underestimated as compounds such as esters and monoter- penes can significantly influence the aromatic composition of the wine delivering great com- plexity and desirable profiles. The sensory results of the selected wines did not always correspond to the chemical profile highlighting the importance of other aroma compounds impacting the wines and interactions occurring between volatile compounds. Analysis of the 2016 Top 10 Sauvignon Blanc wines showed very interesting results for 4MMP. The values ranged from 0 to 122 ng/L, which are huge amounts of this thiol especially con- sidering, in general, that this thiol is mostly absent in wines from other countries. Even to such an extent that some researchers have stopped analyzing for it. From the selection of top 10 wines, the wines containing copious amounts of 4MMP had a distinct black currant character and it added a different dimension to the wines' aromatic characteristics. It would seem as if the presence of 4MMP in South Afri- can wines could give a needed edge to distin- guish the wines in the international market. The above mentioned techniques can be used to tailor-make a wine to fit the aroma profile desired, however, it is not an easy task. Not only is there no guarantee for success, there is the added hurdle of wine complexity where sensory interactions can play a bigger role than anticipated. Sauvignon Blanc needs to be considered holistically by the way the compounds work together to create wine aroma. The presence of other molecules in the wine, whether it be aromatic or non-aromatic, can influence the perception of volatile thiols. This is a complex relationship within the wine medium and there is no real way to control these type of interactions as the effects of many have not been investigated. Some relationships have been studied. The interaction of 3MH with oxidation-related compounds (especially methional, reminis- cent of cooked potato) showed a strong sup- pressive effect with methional reducing the intensity of the fruity aroma significantly. 1 Conversely, acetaldehyde actually enhanced TTB LABEL APPROVALS Low per-label costs Gov't. Liaison Negotiations or Footwork Reasonable Hourly Rates TRADEMARK SEARCHES As Low as $185 Your trade names or designs are searched at the U.S. Patent Office to help establish valuable ownership or avoid costly legal liability. Over 100 years' total staff experience handling every government liaison need for industry. Phone or write for details. 200 N. Glebe Rd., Suite 321 Arlington, Virginia 22203 Phone: (703) 524-8200 Fax: 525-8451 TOLL-FREE 1-800-642-6564 Major Credit Cards Accepted www.trademarkinfo.com Since 1957 GovtLiaison_Dir08 11/29/07 2:00 PM Pag For your nearest dealer, contact: Quick and economical, this long-lasting dripline holder can be installed in seconds. The built-in saddle prevents water flow restriction. Available in 1/2" and 7/8" sizes. Patent No. 4,615,140 DRIPLOK™ Toll-Free: 877-552-4828 909-464-1373 • Fax: 909-464-1603 www.agfast.com WinVineDripLok AD.qxp_Layout 1 12/1/16 2:55 PM