Winemaking in the Classroom 1 Equipment, Yeast, Fruit & Chemicals Sirromet Wines Pty Ltd 850-938 Mount Cotton Rd Mount Cotton Queensland, Australia 4165 www.sirromet.com   Courtesy of Jessica Ferguson Assistant Winemaker & Site Chemist Downloaded from seniorchem.com/eei.html

Requirements Fruit, juice, or juice concentrate Chemicals may include: potassium metabisulphite, tartaric acid, enzymes, bentonite, fining agents Temperature Control Method for fermentation (air-conditioned room as a minimum) Yeast Fermentation Vessels and Equipment Testing Equipment for: pH, SG, Free SO2, temperature, acidity, alcohol Siphon for Racking, Filters, Bottles and Closures

Fruit/Juice: Strongly recommend use of grapes/grape product Possibilities include: Wine grapes, table grapes, grape juice concentrate, raisins soaked or blitzed in water Fruit preparation: ideally low solids, but relative high dissolved oxygen Freshly crushed and pressed juice best option Also preservative free juices, or can soak raisins (must be sulphite free) Canned juices are an option also ‘Cloudy’ juices may work better than filtered juice as they have a higher natural nutrient level

Reasons for Preferring Grapes: Ideal pH range for fermentation (not too high/low) Sugar ratio 50:50 glucose:fructose Naturally high levels of tartaric acid (stability) Better structure to wines Better balance of acid and flavour High number of flavour compounds from grapes vs. other fruit

Potential Issues with Other Fruit Use of other fruit may result in negative flavour and structure characters such as: greenness, bitterness, hardness, ‘thin’ acidic or bitter wines Possible issues with flavour/colour stability, fruit wines often don’t keep well Usually lower alcohol than grape wine – potential for spoilage is higher Sugar balance and acid profiles of other fruits may make them less suitable for fermentation i.e. sweet eating apples: fructose>>glucose – this can cause sluggish ferments

Grape Juice Concentrate Kits Consider as an easy option to get started Can buy ‘kits’ to make red or white wine including all chemicals required Less likely to have stuck ferments with a concentrate kit (but not foolproof!) May be ideal if time is restricted for getting fermentation set up and started

All About Yeast Wine strains best suited (not brewers yeast) Requirements: alcohol tolerant to 15% suited to low pH/low Nitrogen low VA & H2S production medium sugar accumulation

Where to get yeast Where to buy yeast: Laffort (bulk supplier), Sirromet (comes in 500g packs) many home brew shops sell wine yeast in small packs which may be more suitable Comes in freeze-dried form Care of dried yeast: Cool store or fridge, vacuum sealed, 12 months maximum shelf life. Once opened, seal packet with tape, store in fridge and use within a few weeks

Fermentation Equipment Suitable fermentation vessels: Beer kegs, glass demi-johns: no taint Plastic: hydrocarbon pickup, can produce plastic taint in wine Use fermentation bubblers or silicon bungs One way seals, or a plastic bag full of sand.

Fermentation Equipment (cont) If your juice contains solids or skins, or is at higher temps: Initial ferment should be started in a wide necked vessel Bucket or plastic keg (loosely covered to allow CO2 escape) Move to a narrow neck vessel once ferment has become less vigorous

Ferment Monitoring Equipment Refractometer – for measuring Brix on juice pre-ferment Hydrometers: Baume scale (for juice) Specific Gravity (for ferment monitoring) Thermometer or data-logger to monitor temperature Valenche or Wine Thief for sampling (optional)

Sanitation of Equipment Sterilisation (heat) – could rinse/soak clean vessels in boiling water – limited effectiveness, or boil small pieces of equipment Chemical sterilisation – hypochlorite (bleach) – rinse very, very well after Chemical sterilisation – caustic wash followed by acid wash, water rinse Chemical sterilisation – sulphite solution

Chemicals Tartaric acid – to adjust acidity of must before or after ferment (can be used for any fruit/juice) Yeast Nutrient – DAP or Fermaid Sugar (if required) – use table sugar Enzyme – to assist with cold settling of high solids juice pre-ferment Potassium metabisulphite or Camden tablets – SO2 preservative and/or sanitiser Bentonite – kaolin clay base used to aid clarification after fermentation (comes in dry form)

Processing & Finishing Equipment Fruit press – for grapes or soft fruit, table top, manual stainless steel Siphon tubes – clear plastic tubing is effective (silica or PVC food grade) Filtration options – most are beyond the classroom budget, but gravity filters or small electric filters are available Bottles and screw-caps or corks

Some useful links for businesses that sell winemaking supplies www.ibrew.com.au 12-16 Tonga Place, Parkwood www.homebrewbarn.com 325 Gympie Rd Kedron www.uq.net.au/homebrew 69 Shore St, Cleveland www.nerangbrewing.com.au 41 Price St Nerang or Shop 9, Oxenford Square Shopping Centre, Old Pacific Highway, Oxenford Many other large home brew shops may have equipment/kits www.winequip.com.au - not in Qld, high quality home winemaking equipment by mail order, well-priced Carlton Glass (Sunshine Coast) www.carltonglass.com.au manufacturer of hydrometers and other wine testing glassware