INTERNATIONAL WINE TECHNICAL FORUM, 2015 SUGAR METHODS DISCUSSION Steve Tallman 6 th May, 2015

Agenda Definition of wine sugar content Sugar composition of wine Labeling terms for wine sweetness Historical sugar method performance Sugar data comparison across methods Sugar compendia (draft) Laboratory quality assurance practices PRESENTATION TITLE HERE

Definition of Sugar Content Terms Reducing Sugars:  Includes any sugar with a aldehyde group (glucose + fructose)  Sucrose is not a reducing sugar  Should not be confused with other reducing substances Residual Sugar:  All fermentable sugars including Sucrose & Pentoses Reducing substances:  Includes glucose and fructose plus oligosaccharides, and other reducing matter (i.e. tannins and polyphenols) Non-fermentable carbohydrates includes:  polysaccharides, pectins, tannins, pigments, organic acids

Typical Sugar Composition in Wine Glucose – 47.6% Fructose – 47.6%* Sucrose – 3.1% Pentoses – 1.1% Pectins – 0.6% * Fructose is approx. 2X sweeter than Glucose

Sugar Labeling Terms OIV defines wine by sugar content 1  Dry: Contains a max of 4 g/L sugar content 2  Demi-sec: >4 g/L - 12 g/L sugar content 3  Semi-sweet: > g/L sugar content  Sweet: >45 g/L sugar content 1 OIV (18/73, Eco 3/03) 2 Or 9 g/L when the level of acidity of TA ≤ 2 g/L less that the sugar content. 3 Or 18 g/L when the content of TA is ≤ 2 g/L less that the sugar content.

Sugar Methods of Analysis MethodMeasures Instrument Technique TypeCalibrationPerformance OIV Method Reference PopularityComments HPLC Residual Sugar/Reducing substances HPLC-RIPrimary Glucose, Fructose, Sucrose Robust OIV-MA- As Low Quantifies separate sugars, calibration? EnzymaticReducing Sugar Manual or automated Primary Glucose + Fructose Very robust OIV-MA- As HighMost common EnzymaticResidual Sugar Manual or automated Primary Glucose + Fructose + Sucrose Very Robust OIV-MA- As Low Requires invertase to convert sucrose into glucose and fructose FTIRReducing sugar WineScan, OenoFoss, Bruker Alpha, Other Secondary Performance depends on calibration Depends on many variables, QA requirements Mod Depends on calibration for quantification Lane EnyonResidual SugarTitrationPrimaryDextroseTechnique dependent LowLacks specificity PRESENTATION TITLE HERE Between lab SD are much lower in Reducing Sugar methods. Enzymatic method showed the lowest differences from Grand Mean.

Historical CTS Sugar PT Data PRESENTATION TITLE HERE Thirteen Years of CTS Winery Laboratory Collaborative Data Howe, P.A., Sacks, G.L., and S.E. Ebeler Am J Enol Vitic

Sugar Data Comparison Wine Varietal Reducing Sugar -Enzymatic Glucose+Fructose Residual Sugar – HPLC/RI Glucose+Fructose+Sucrose Difference* g/L Chardonnay880.0 Sparkling wine Cabernet White Zin Pinot Noir Generic red Chardonnay Merlot * Average Difference = 0.8 g/L

Fit-for Purpose Sugar Compendia Fit-For-Purpose Working Group: Sugar Compendia (Draft) CountryDefinition of sugar content (i.e. the Chinese are now referring to it as “reducing substances” Methods of analysis (if stated) and units of measure Labeling requirements – definitions of sugar concentration and labeling compliance Other relevant regulatory or compliance information USAResidual sugars = mono- and di- saccharides TTB uses (but does not require others to use) an HPLC method that detects glucose, fructose, and sucrose and reports out in g/100mL. Optional – Nutritional information is optional on labels or in advertising. If used, TTB requires “complete information about the calorie, carbohydrate, protein, and fat content”, among other things. This must be either a statement of average analysis in accordance with TTB Ruling or a Serving Facts label in accordance with TTB Ruling Calories per serving must be within +5 or -10 of the labeled or advertising caloric content. Other values” are: “within a reasonable range below the [stated] amount but, in no case, more than 20% above [that] amount.” AustraliaImporting country requirements Australia does not require specific methods for analysis domestically (not required in regulation), thus methods use are those required by importing country requirements. NA

Reducing Sugar-Lab Quality Control PRESENTATION TITLE HERE Grand Mean +1 SD +2 SD +3 SD -1 SD -2 SD -3 SD

Thank You! Questions? PRESENTATION TITLE HERE