Filtration and Winery Size:Selecting an Appropriate

Filtration System

Glenn CurtisWidmer Wine Cellars

32nd Annual NY Wine Industry WorkshopApril 2nd, 2003

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.

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!

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

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.

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.

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

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

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.

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.

Q & A