Reasons to Filter

1. Filtration and Winery Size:Selecting an Appropriate Filtration SystemGlenn CurtisWidmer Wine Cellars32nd Annual NY Wine Industry WorkshopApril 2nd, 2003

2. Reasons to Filter • Financial: • Increase yields, less product disposed of. • Less settling time required allowing better tank utilization. • Up-stream filtration extends life of down-stream filters. • Higher quality, less risk exposure to wine going “bad.” • Quality: • Reduce solids levels in juice before fermentation. • Better control of “stop fermentation” wines. • Microbial stability in bulk storage/aging and bottled wine. • Appearance, consumer acceptance.

3. Factors in Deciding to Filter or not? • Know your consumer: are they well educated about wine, will they accept crystals, sediment, less than perfect clarity? • Know your market: is the wine sold and consumed locally, do you have wider distribution entailing more risk? • Know your wine: Alcohol %, pH, residual sugar, ML+, FSO2, Sorbate • Know your comfort level for Risk!

4. Factors in Deciding Appropriate Filtration System • Look at multiple use equipment versus single use equipment: • Plate & Frame lees filter for juice and wine recovery using perlite or D.E. • Pressure leaf filters using various grades of DE for post fermentation, post cold stability, pre-filtration before sterile filters • Filter press with cellulose filter pads, single use with different grade pads or dead plate for multi-use at same time

5. Factors in Deciding Appropriate Filtration System • Size equipment for appropriate flow rate taking into account capital cost, labor cost and future growth. • Take into account any disposal cost of used filter media. • When looking at new technology to replace existing equipment, calculate IRR, NPV and payback period.

6. Factors in Deciding Appropriate Filtration System • Take into account safety concerns using DE and associated cost (dust mask, collection systems) • Decide if all of the “bells and whistles” like automatic CIP and operator controls really needed and cost effective. • Take into account cost of service, repair, cost of down time to process stream.

7. Factors in Deciding Appropriate Filtration System • Look at new “reusable” filter media options • Back-flushable cellulose pads and membrane cartridges • Can have significant cost savings implications: • cellulose pads …saw a 50% reduction in usage • membrane filter …currently on set that is 2 years old and has 1.8 million gallon throughput

8. Factors in Deciding Appropriate Filtration System • Explore other options like cross-flow, micro-filtration, ultra-filtration, reverse osmosis. • Depending on situation, may or may not be economically feasible. • Look at other areas in winery needing filtration: compressed air, process water

9. Filtering for Sterility • Considered a “must” for wines with residual sugar and mixture of ML/non-ML wines. • Should test for residual malic acid at end of ML fermentation to make sure complete. • Need to ascertain risk of contamination by spoilage organisms: Acetobacter, Brettanomyces and Zygosaccharomyces. • Should do base line micro-plating to find out what level of risk is.

10. Filtering for Sterility • Zygo: Extraordinarily resistant to common preservatives • Sulfur Dioxide  120 ppm free (3mg/L molecular @ 3.4 pH) • Sorbic Acid 600 - 800 mg/L • Benzoic Acid 600 - 1,000 mg/L • Ethanol  18 % (v/v) • 1 cell in 5 liters can cause spoilage • Case in point, one large winery dumped 60,000 cs. over a 2 year period. • Case in point, another large winery put 600,000 cs on hold for 3-6 months over a 2 year period and dumped 2,000 cs.

11. Q & A