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{"id":1582181509,"title":"HI 83748-02 Photometer for the Determination of Tartaric Acid in Wine","handle":"hi-83748-02","description":"\u003cp\u003e \u003c\/p\u003e\n\u003cdiv id=\"Product-Body\"\u003e\n\u003cp\u003e\u003cstrong\u003eTartaric Acid: Wine Acidity\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTartaric acid and tartrate play an important role in the stability of wines. They can be present in wine and juice in various forms. like tartaric acid (H2T). potassium bi-tartrate (KHT) or calcium tartrate (CaT). The ratio of these depends mainly on the pH of the wine. The percent of tartrate present as bitartrate (HT-) is maximum at pH 3.7.\u003c\/p\u003e\n\u003cp\u003eThe formation of crystalline deposits (tartrate casse) is a phenomenon of wine aging that does not meet customer acceptance. It is therefore important to test for. and to reduce the potential of bottle precipitation. For example. by adjusting the pH of the wine. winemakers can significantly influence the potential of casse formation.\u003c\/p\u003e\n\u003cp\u003ePotassium concentrations in wine can range from 600 to 2500 mg\/L (ppm) in certain red wines. Although the potassium bi-tartrate is soluble in water. alcohol and low temperatures decrease its solubility. Especially during the alcoholic fermentation potassium bi-tartrate becomes increasingly insoluble resulting in super-saturation and precipitation. The KHT stability can be restored by chilling (with or without seeding). Wines with initial pH values below 3.65 can show a reduction in pH during cold stabilization because of generation of one free proton for each KHT precipitated. The pH may drop as much as 0.2 pH unites. For wines at higher pH than 3.7. the pH shifts to a higher pH.\u003c\/p\u003e\n\u003cp\u003eCalcium concentrations can range from 6 to 165 mg\/L (ppm) and may complex with tartrate or oxalate to form crystalline precipitates. Calcium tartrate instabilities occur normally from 4 to 7 months after fermentation and are temperature independent.\u003c\/p\u003e\n\u003cp\u003eSulphates. proteins. gum and polyphenols can form stable complexes with tartrate thus inhibiting casse formation. The complexes are mainly between polyphenols and tartaric acid in red. and proteins in white wine. This explains why. as pigment polymerization occurs. the holding capacity of tartaric acid diminishes. resulting in delayed casse. The sulfate instead does not complex with potassium from 50% in white wines up to 100% in red ones.\u003c\/p\u003e\n\u003cp\u003eTartaric acid concentrations in wine range normally from 1.5 to 4.0 g\/L. This acid concentration may not be confused with total or titratable acidity of wines that are often expressed in tartaric acid content too. Although it is the tartaric acid that is the predominantly present acid (up to 60% of the total acidity). others like malic. citric and several volatile acids do give a significant contribution total acidity.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOrder Information:\u003c\/strong\u003e\u003cbr\u003eHI 83748-01 (115V) and HI 83748-02 (230V) are supplied with sample cuvettes and caps (2). reagents for 5 tests (HI 83748A-O. HI 83748B-O). 200 µL automatic pipette with Instruction Sheet. plastic tips for 200 µL automatic pipette (2). 5 mL syringe with tip. cuvette cleaning cloth. 12 VDC adapter. batteries. instructions. instrument quality certificate and rugged carrying case.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"TabbedPanels\" id=\"TabbedPanels1\"\u003e\n\u003cul class=\"TabbedPanelsTabGroup\"\u003e\n\u003cli class=\"TabbedPanelsTab TabbedPanelsTabSelected\"\u003eSpecifications\u003c\/li\u003e\n\u003cli class=\"TabbedPanelsTab\"\u003eAccessories\u003c\/li\u003e\n\u003cli class=\"TabbedPanelsTab\"\u003eDownloads\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"TabbedPanelsContentGroup\"\u003e\n\u003cdiv class=\"TabbedPanelsContent TabbedPanelsContentVisible\"\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eRange\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e0.0 to 5.0 g\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e0.1 g\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAccuracy @25°C\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e±0.1 g\/L ±5% of reading\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLight Source\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003etungsten lamp\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLight Detector\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003esilicon photocell with narrow band interference filter @ 525 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMethod\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003ethe reaction between tartaric acid and the reagents causes a yellow\/orange red tint in the sample.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnvironment\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e0 to 50°C; RH max 95% non-condensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery Type\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e1.5V AA batteries (4) \/ 12 VDC adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAuto-off\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003eafter 15 minutes of non-use\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e225 x 85 x 80 mm (8.7 x 3.3 x 3.1\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e500 g (17.6 oz.)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cdiv\u003e\u003cstrong\u003eProduct Manuals\u003c\/strong\u003e\u003c\/div\u003e\n\u003cp\u003e\u003cimg width=\"20\" height=\"22\" align=\"absmiddle\" alt=\"\" src=\"http:\/\/www.hannainst.com\/usa\/images\/icon-pdf.gif\" border=\"0\"\u003e\u003cspan\u003e  Manual: \u003c\/span\u003e\u003ca title=\"Download Product Manual\" href=\"http:\/\/www.hannainst.com\/manuals\/manHI_83748.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eDownload\u003c\/a\u003e\u003c\/p\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eSolutions\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%2093703-50\"\u003eHI 93703-50\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eCuvette Cleaning Solution\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eAccessories\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20740226\"\u003eHI 740226\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eGraduated Syringe. 5 mL\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731350\"\u003eHI 731350\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003ePlastic Tip Set for 200 µL Graduated Pipette\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20740027P\"\u003eHI 740027P\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003e1.5V AA Battery Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731318\"\u003eHI 731318\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eCuvette Cleaning Cloth\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731321\"\u003eHI 731321\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eGlass Cuvette Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731325W\"\u003eHI 731325W\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eCap Set for Glass Cuvettes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eReagents \u0026amp; Standards\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%2083748-20\"\u003eHI 83748-20\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eTartaric Acid Reagents\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","published_at":"2016-09-01T16:17:56+12:00","created_at":"2015-09-01T15:17:47+12:00","vendor":"HANNA Instruments Inc.","type":"Electrochemical","tags":["brand_Hanna","category_photometers"],"price":93000,"price_min":93000,"price_max":93000,"available":true,"price_varies":false,"compare_at_price":null,"compare_at_price_min":0,"compare_at_price_max":0,"compare_at_price_varies":false,"variants":[{"id":4857322053,"title":"Default Title","option1":"Default Title","option2":null,"option3":null,"sku":"HI 83748-02","requires_shipping":false,"taxable":true,"featured_image":null,"available":true,"name":"HI 83748-02 Photometer for the Determination of Tartaric Acid in Wine","public_title":null,"options":["Default Title"],"price":93000,"weight":0,"compare_at_price":null,"inventory_quantity":1,"inventory_management":null,"inventory_policy":"deny","barcode":""}],"images":["\/\/cdn.shopify.com\/s\/files\/1\/0931\/0956\/products\/hi83748_200_2015.jpeg?v=1443495801"],"featured_image":"\/\/cdn.shopify.com\/s\/files\/1\/0931\/0956\/products\/hi83748_200_2015.jpeg?v=1443495801","options":["Title"],"content":"\u003cp\u003e \u003c\/p\u003e\n\u003cdiv id=\"Product-Body\"\u003e\n\u003cp\u003e\u003cstrong\u003eTartaric Acid: Wine Acidity\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTartaric acid and tartrate play an important role in the stability of wines. They can be present in wine and juice in various forms. like tartaric acid (H2T). potassium bi-tartrate (KHT) or calcium tartrate (CaT). The ratio of these depends mainly on the pH of the wine. The percent of tartrate present as bitartrate (HT-) is maximum at pH 3.7.\u003c\/p\u003e\n\u003cp\u003eThe formation of crystalline deposits (tartrate casse) is a phenomenon of wine aging that does not meet customer acceptance. It is therefore important to test for. and to reduce the potential of bottle precipitation. For example. by adjusting the pH of the wine. winemakers can significantly influence the potential of casse formation.\u003c\/p\u003e\n\u003cp\u003ePotassium concentrations in wine can range from 600 to 2500 mg\/L (ppm) in certain red wines. Although the potassium bi-tartrate is soluble in water. alcohol and low temperatures decrease its solubility. Especially during the alcoholic fermentation potassium bi-tartrate becomes increasingly insoluble resulting in super-saturation and precipitation. The KHT stability can be restored by chilling (with or without seeding). Wines with initial pH values below 3.65 can show a reduction in pH during cold stabilization because of generation of one free proton for each KHT precipitated. The pH may drop as much as 0.2 pH unites. For wines at higher pH than 3.7. the pH shifts to a higher pH.\u003c\/p\u003e\n\u003cp\u003eCalcium concentrations can range from 6 to 165 mg\/L (ppm) and may complex with tartrate or oxalate to form crystalline precipitates. Calcium tartrate instabilities occur normally from 4 to 7 months after fermentation and are temperature independent.\u003c\/p\u003e\n\u003cp\u003eSulphates. proteins. gum and polyphenols can form stable complexes with tartrate thus inhibiting casse formation. The complexes are mainly between polyphenols and tartaric acid in red. and proteins in white wine. This explains why. as pigment polymerization occurs. the holding capacity of tartaric acid diminishes. resulting in delayed casse. The sulfate instead does not complex with potassium from 50% in white wines up to 100% in red ones.\u003c\/p\u003e\n\u003cp\u003eTartaric acid concentrations in wine range normally from 1.5 to 4.0 g\/L. This acid concentration may not be confused with total or titratable acidity of wines that are often expressed in tartaric acid content too. Although it is the tartaric acid that is the predominantly present acid (up to 60% of the total acidity). others like malic. citric and several volatile acids do give a significant contribution total acidity.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOrder Information:\u003c\/strong\u003e\u003cbr\u003eHI 83748-01 (115V) and HI 83748-02 (230V) are supplied with sample cuvettes and caps (2). reagents for 5 tests (HI 83748A-O. HI 83748B-O). 200 µL automatic pipette with Instruction Sheet. plastic tips for 200 µL automatic pipette (2). 5 mL syringe with tip. cuvette cleaning cloth. 12 VDC adapter. batteries. instructions. instrument quality certificate and rugged carrying case.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"TabbedPanels\" id=\"TabbedPanels1\"\u003e\n\u003cul class=\"TabbedPanelsTabGroup\"\u003e\n\u003cli class=\"TabbedPanelsTab TabbedPanelsTabSelected\"\u003eSpecifications\u003c\/li\u003e\n\u003cli class=\"TabbedPanelsTab\"\u003eAccessories\u003c\/li\u003e\n\u003cli class=\"TabbedPanelsTab\"\u003eDownloads\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"TabbedPanelsContentGroup\"\u003e\n\u003cdiv class=\"TabbedPanelsContent TabbedPanelsContentVisible\"\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eRange\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e0.0 to 5.0 g\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e0.1 g\/L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAccuracy @25°C\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e±0.1 g\/L ±5% of reading\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLight Source\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003etungsten lamp\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLight Detector\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003esilicon photocell with narrow band interference filter @ 525 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMethod\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003ethe reaction between tartaric acid and the reagents causes a yellow\/orange red tint in the sample.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnvironment\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e0 to 50°C; RH max 95% non-condensing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBattery Type\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e1.5V AA batteries (4) \/ 12 VDC adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAuto-off\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003eafter 15 minutes of non-use\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e225 x 85 x 80 mm (8.7 x 3.3 x 3.1\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e \u003c\/td\u003e\n\u003ctd\u003e500 g (17.6 oz.)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cdiv\u003e\u003cstrong\u003eProduct Manuals\u003c\/strong\u003e\u003c\/div\u003e\n\u003cp\u003e\u003cimg width=\"20\" height=\"22\" align=\"absmiddle\" alt=\"\" src=\"http:\/\/www.hannainst.com\/usa\/images\/icon-pdf.gif\" border=\"0\"\u003e\u003cspan\u003e  Manual: \u003c\/span\u003e\u003ca title=\"Download Product Manual\" href=\"http:\/\/www.hannainst.com\/manuals\/manHI_83748.pdf\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eDownload\u003c\/a\u003e\u003c\/p\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eSolutions\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%2093703-50\"\u003eHI 93703-50\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eCuvette Cleaning Solution\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eAccessories\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20740226\"\u003eHI 740226\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eGraduated Syringe. 5 mL\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731350\"\u003eHI 731350\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003ePlastic Tip Set for 200 µL Graduated Pipette\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20740027P\"\u003eHI 740027P\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003e1.5V AA Battery Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731318\"\u003eHI 731318\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eCuvette Cleaning Cloth\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731321\"\u003eHI 731321\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eGlass Cuvette Set\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%20731325W\"\u003eHI 731325W\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eCap Set for Glass Cuvettes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eReagents \u0026amp; Standards\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"http:\/\/www.hannainst.com\/usa\/prods2.cfm?id=009006\u0026amp;ProdCode=HI%2083748-20\"\u003eHI 83748-20\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003eTartaric Acid Reagents\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e"}

HI 83748-02 Photometer for the Determination of Tartaric Acid in Wine

Product Description

 

Tartaric Acid: Wine Acidity

Tartaric acid and tartrate play an important role in the stability of wines. They can be present in wine and juice in various forms. like tartaric acid (H2T). potassium bi-tartrate (KHT) or calcium tartrate (CaT). The ratio of these depends mainly on the pH of the wine. The percent of tartrate present as bitartrate (HT-) is maximum at pH 3.7.

The formation of crystalline deposits (tartrate casse) is a phenomenon of wine aging that does not meet customer acceptance. It is therefore important to test for. and to reduce the potential of bottle precipitation. For example. by adjusting the pH of the wine. winemakers can significantly influence the potential of casse formation.

Potassium concentrations in wine can range from 600 to 2500 mg/L (ppm) in certain red wines. Although the potassium bi-tartrate is soluble in water. alcohol and low temperatures decrease its solubility. Especially during the alcoholic fermentation potassium bi-tartrate becomes increasingly insoluble resulting in super-saturation and precipitation. The KHT stability can be restored by chilling (with or without seeding). Wines with initial pH values below 3.65 can show a reduction in pH during cold stabilization because of generation of one free proton for each KHT precipitated. The pH may drop as much as 0.2 pH unites. For wines at higher pH than 3.7. the pH shifts to a higher pH.

Calcium concentrations can range from 6 to 165 mg/L (ppm) and may complex with tartrate or oxalate to form crystalline precipitates. Calcium tartrate instabilities occur normally from 4 to 7 months after fermentation and are temperature independent.

Sulphates. proteins. gum and polyphenols can form stable complexes with tartrate thus inhibiting casse formation. The complexes are mainly between polyphenols and tartaric acid in red. and proteins in white wine. This explains why. as pigment polymerization occurs. the holding capacity of tartaric acid diminishes. resulting in delayed casse. The sulfate instead does not complex with potassium from 50% in white wines up to 100% in red ones.

Tartaric acid concentrations in wine range normally from 1.5 to 4.0 g/L. This acid concentration may not be confused with total or titratable acidity of wines that are often expressed in tartaric acid content too. Although it is the tartaric acid that is the predominantly present acid (up to 60% of the total acidity). others like malic. citric and several volatile acids do give a significant contribution total acidity.

 

Order Information:
HI 83748-01 (115V) and HI 83748-02 (230V) are supplied with sample cuvettes and caps (2). reagents for 5 tests (HI 83748A-O. HI 83748B-O). 200 µL automatic pipette with Instruction Sheet. plastic tips for 200 µL automatic pipette (2). 5 mL syringe with tip. cuvette cleaning cloth. 12 VDC adapter. batteries. instructions. instrument quality certificate and rugged carrying case.

  • Specifications
  • Accessories
  • Downloads
Range   0.0 to 5.0 g/L
Resolution   0.1 g/L
Accuracy @25°C   ±0.1 g/L ±5% of reading
Light Source   tungsten lamp
Light Detector   silicon photocell with narrow band interference filter @ 525 nm
Method   the reaction between tartaric acid and the reagents causes a yellow/orange red tint in the sample.
Environment   0 to 50°C; RH max 95% non-condensing
Battery Type   1.5V AA batteries (4) / 12 VDC adapter
Auto-off   after 15 minutes of non-use
Dimensions   225 x 85 x 80 mm (8.7 x 3.3 x 3.1")
Weight   500 g (17.6 oz.)
Product Manuals

  Manual: Download

Solutions
HI 93703-50 Cuvette Cleaning Solution
Accessories
HI 740226 Graduated Syringe. 5 mL
HI 731350 Plastic Tip Set for 200 µL Graduated Pipette
HI 740027P 1.5V AA Battery Set
HI 731318 Cuvette Cleaning Cloth
HI 731321 Glass Cuvette Set
HI 731325W Cap Set for Glass Cuvettes
Reagents & Standards
HI 83748-20 Tartaric Acid Reagents

This product is available upon request. Contact us for more information.