ask the Back to Vintage with Download the 2018 Vintage Catalogue at grapeworks.com.au Wine-Making Wine instabilities - the Additives Cleaning Grapeworks has an extensive Tools range of yeasts, enzymes, tanins, Food Grade malo bacteria and other solids won’t hurt you wine-making additives. Plastic A range of hazes and deposits can form in wine and these can sometimes cause concerns for consumers. The AWRI helpdesk has recently received queries asking if there are any health risks associated with consuming wines affected by hazes or deposits. This column discusses the common Food Grade Polyethylene. instabilities seen in wine and provides reassurance that they do not pose health or safety risks. 225L, 350L, 500L, Ferment 700L, 1000L Vats What are the most common instabilities found in wine? Hazes and deposits in packaged wine consistently make up around 40% of investigations conducted by the AWRI IBC helpdesk. The majority of these are protein, 1000L IBC EVOH oxygen barrier tank with steel pallet and frame. tartrate crystals and wine yeast/bacteria. Bin Liners Grape protein hazes in wine Liners for harvest and fermenting. Packs of 5 or Rolls of 40 units. Wine-grapes contain proteins that Nally Mega Bins persist through the winemaking process Square food grade polyethylene. Solid and vented bins with and can cause hazes in finished wine. optional gal tipping bars. Wineries usually prevent protein hazes by using bentonite fining to remove most of the haze-forming proteins from wine prior to bottling. In some cases insufficient fining can result in residual soluble grape VC Tanks Variable Capacity Tanks proteins remaining in wine, or late copper High quality flat bottom stainless steel VC tanks with floating lid additions to wine before bottling can result and kit. Tanks inner are mirror polished for easy cleaning. in formation of a copper-protein complex, which can come out of solution and form tartrate can also form in some wines with reactions occur following inhalation of Capacity 100L 230L 330L 530L 1000L a haze once the wine is bottled. Similar to high calcium levels. Being non-toxic and yeast in its aerosolised form rather than Diameter mm 470 620 620 750 1020 those in cloudy apple and pear juices, or non-allergenic, tartrates are actually from consuming foods or beverages made Height mm 800 820 1160 1270 1400 cloudy beers and ciders, the ‘solids’ simply commonly used as food additives (such as with the microorganism. Natural wines, or affect the appearance and texture of the cream of tartar used in baking) and pose deliberately unfiltered and unfined wines, Seal Size mm Ø 450 600 600 700 1000 product consumed. These types of proteins no health risks if consumed. often contain residual yeast lees to aid in Outlet mm 12 25 25 25 25 are non-toxic and non-allergenic, and are wine texture. Many other food products Suction Hose Large range of replacement VC seals available. also contain microbiological species, such found in other fruits and vegetables. While Yeast and bacteria 25, 50, 75 & 100mm ø. CALL FOR VC TANKS 1500 & 2000 LITRE. a protein haze, particularly in white wine, Yeast and bacteria are commonly as yoghurts or probiotic milk drinks. may not look attractive, it poses no risks to found in deposits in wine, due either human health. to insufficient filtration or yeast and Fining agents bacterial growth in wine post-bottling. Different types of fining agents can Tartrate crystals Fortunately, the pH, sulfite and alcohol be used when clarifying wine. Many Ferment Covers Crystals of potassium bitartrate (KHT) conditions typically found in wine make it of these are proteins derived from egg, Covertec breathable and non-breathable covers are are one of the most common deposits an environment that is extremely hostile fish, gelatine or milk and as such have found in wine. Grape juice naturally to food-borne pathogenic organisms, potential to cause allergic reactions in ideal for open fermenters. Keep out fruit flies, wasps contains both potassium and tartaric acid, ensuring wine presents a low risk to health some consumers. Research has shown that and contaminants. Complete range of square which associate together to form KHT from a microbiological perspective. Good Manufacturing Practice ensures rectangular and round covers available. crystals. After fermentation, when wine The most common microorganisms that minimal residual protein remains in becomes saturated with KHT at levels detected in packaged wine are the the final wine, at amounts not associated greater than its solubility in an ethanol/ yeast that conducts wine fermentation, with adverse reactions in food allergic water solution, it drops out of solution Saccharomyces cerevisiae, which is consumers. When making wines suitable Aird Cleaning Chemicals as crystals. To a consumer, KHT crystals also used in baking and brewing, and for vegans, winemakers can now choose Clean and sanitise sustainably. Remove wine tartar, colour, neutralise might look like small glass shards in white the bacteria that conducts malolactic plant-based clarifying agents instead of bacteria, microbes, black mould etc. Meets Food Codex, FSANZ & wine. In red wine, they are usually dark fermentation, Oenococcus oeni. These animal-derived products. organic production by OFA. red in colour and could be mistaken for organisms are not harmful to humans residual colour, tannin or even pieces of when consumed. It is also unlikely that For further information about deposits oak/wood. These crystals often dissolve wine consumers with an allergy to baker’s in wine or any other technical matter, Download the 2018 Vintage National 03 9555 5500 upon touch, or, if consumed, present yeast will react adversely to wine, bread please contact the AWRI helpdesk on (08) as a gritty texture. Crystals of calcium or beer, because generally such allergic 8313 6600 or email [email protected] Catalogue at grapeworks.com.au Email [email protected] www.grapeworks.com.au 66 Grapegrower & Winemaker www.winetitles.com.au February 2018 – Issue 649