Issue link: http://winesandvines.uberflip.com/i/987926
56 WINES&VINES June 2018 WINEMAKING Although the above information has been submitted to TTB, the agency has not given final approval of this product. Apparently, TTB would like to hear from industry people that winemakers want to use this product before the agency will give its approval. I suggest that wineries send their comments and urge TTB to approve Zenith for use in wine production. Lactobacillus plantarum There is a wealth of active research on alter- nate organisms to Oenococcus oeni for conver- sion of malic acid into lactic acid. However, some of the reported literature has been inac- curate in its interpretation. Among many different strains of LAB (Lac- tobacillus Bacteria spp), L. plantarum is one of the better organisms for acid conversion, es- pecially for higher pH wines (above 3.4). In addition, its diverse and complex metabolic pathways provide complexity to wines, accord- ing to Lucio et al. 1 The research on this organism addresses three methods: inoculation of LAB into must pre-alcoholic fermentation, co-inoculation and addition post-alcoholic fermentation. Despite the inference by Lucio et.al. that pre-alcoholic fermentation is the preferred method, in my discussions with colleagues involved in current research, there seems to be a changing con- sensus that co-inoculation might be the better method. This conclusion developed and evolved as several strains have been identified and selected that are better suited to this pro- duction environment. These strains are more complete in their metabolism of malic acid into lactic acid, especially in high-pH wines. Malolactic-fermentation organisms have two types of metabolic pathways for basic respiration: heterofermentative and homofer- mentative. O. oeni is heterofermentative, meaning it will use multiple energy sources for survival, including hexoses. L. plantarum, in contrast, is not able to metabolize hexoses, which means that O. oeni can produce acetic acid but L. plantarum will not. LAB organisms have been saddled with another misconception 3,4 : That they produce biogenic amines and carbamates, neither of which are desirable in wines. Biogenic amines are compounds responsible for causing head- aches as well as noxious aromas and flavors. No producer wants putrescine or cadaverine in its wines, and consumers who are sensitive to histamine or tyramine don't want them, either. Through research, we now know that cer- tain LAB organisms, including L. plantarum, do not produce biogenic amines or carbamates, but actually degrade and remove those sub- stances from the wines in which they are used for MLF. 2 It also has been found that S. cerevi- siae and O. oeni are active producers of acetic acid, biogenic amines and carbamates. Often in stressed fermentations S. cerevisiae produces significant quantities of biogenic amines. The carbamates might be produced by certain LAB, but not by L. plantarum. Unfortunately, there is a lot of old informa- tion online that has not been updated. One example is the University of California, Davis Department of Viticulture and Enology's web- site. In their descriptions of various bacterial species, the site specifically mentions that there is concern about the L. plantarum organism as a possible producer of acetic acid, biogenic amines and carbamates. This mention might be one of the reasons TTB has not acted on adding L. plantarum to the list of approved organisms. Similar to the Zenith product, perhaps the only way L. plantarum will be allowed for use in wine production will be if the industry peti- tions TTB. Those wineries or winemakers who would like to see how this organism will affect their wine production can obtain limited sam- ples of L. plantarum from Lallemand. If a winery decides to try this organism, Lallemand requests that they co-inoculate with yeast. In addition, the winery must understand that it won't be able to sell wine treated with L. plan- tarum, at least in the short term. It should be noted that winemakers should not go to ATCC to purchase off-the-shelf cul- tures because they likely will be dissatisfied with the results. Companies such as Lallemand that provide yeast specifically for winemaking have found that L. plantarum must be grown in a specific culture solution to stabilize it and tune its tolerance for wine. The fact that L. plantarum is approved for use in beer, but not wine has led to a "Call to Arms" to petition the TTB to allow the use of Lactobacillus plantarum as an alternate organ- ism to O. oeni. If readers agree with the propo- sition, they can write to TTB at the address below to ask not only for the ability to trial-test this organism, but for its experimental use and sale in the production of wine. Despite re- peated attempts, TTB has not returned calls requesting answers about their reasoning for not allowing its use in wine. Lallemand staff members said they have had the same experience. If readers agree with the proposition, they can write to TTB at Alcohol and Tobacco Tax and Trade Bureau, 1310 G Street, Washington, DC 20004 to ask not only for the ability to trial-test this organism, but for its experimental use and sale in the production of wine. Richard Carey, Ph.D., is a wine consultant in Lancaster, Pa., and owner of Tamanend Wine, Inc. Figure 3: Cold stabilization of wine using MTA is temporary, due to hydrolysis after 12 months in the bottle. Figure 4: In comparison with other methods of treating the wine, colloid com- pounds provide cold stabilization using the least amount of water. To see references for this article, go to winesandvines.com and search under Magazine › Features › June 2018. K-POLYASPARTATE: PERFORMANCE STABILIZATION WITH COLLOIDS: KEY BENEFITS Resistance over time Greater sustainability of winemaking process: Water consumption Potable water used (L/hL) 0 5 10 15 20 Protecting Colloids C.E. Resins Electrodialysis Cold Control 10 g/hL KPA 10 g/hL MTA 0.6 0.5 0.4 0.3 0.2 0.1 0 Cabernet Sauvignon DH 2 T (g/L) after cold test n 0 months n 5 months n 12 months Cold test: wine stored at -4°C during 6 days