We at The Wine Blokes have to admit we are idealists when it comes to growing and making great wine. The overwhelming philosophy is that to make good wine you need good fruit. This obviously requires the careful attention and nurturing of the grapes in the vineyard throughout the growing season. If you’ve planted the right varieities in the right region, and follow the right management techniques and focus on quality you will end up with great fruit, right?? Well, most of the time this is the case, but sometimes mother nature will decide she’s had enough and will deliver the biggest right hook to send you tumbling to the canvas. This is what has just happened to many vintners around some of Australias’ premiere wine regions this vintage. While many regions in Australia suffer cooler and wetter desired temperatures toward the end of vintage, it its rare that temperatures rise to such an extreme as to cause irreversible damage to the remaining grapes on the vine. Blame it on climate change or El Nino if you like, but for 15 days straight in March this year, temperatures in Adelaide and surrounding grape growing regions rose to above 35 degrees celsius (an all time Australian record).

Any remaining grapes on the vine were fried, causing mass dehydration and shrivelling, concetrating sugar where Baumes raced to unbelievable levels. So much for Australian wines becoming more refined, delicate and lower in alcohol.

There is not alot winemakers can do to make adequeate wines under these circumstances. Alcohol levels become excessive, yeast have a tough time completing fermentation, and volatile acidity can become a problem. Short of adding water (which is illegal), what choices do winemakers have? There really is nothing that can be done to transform these wines into the same condition as if mother nature had provided a good season.

Enter Memstar, and boy are these guys going to be busy over the next few months. Memstar offers essentially a wine doctor service where undesirable components in wines are removed, particularly:

- alcohol reduction

- smoke taint

- brettanomyces removal

- volatile acidity removal

- flavour conentration

- salt removal

The Mems-t-a-r Process:

The Memstar processes have in common the concept of Membrane Separation Treatment And Recombination.

Membrane

Memstar reverse osmosis equipment is the basis of all the other Memstar processes. Wine is pumped at high pressure past a semi-permeable membrane.

Separation

The wine to be treated is separated by a reverse osmosis membrane into concentrate and permeate flows. The permeate (about 15% of the original flow) contains small molecules from the wine which have passed through the membrane differentially according to their size. The wine and most of its vinous components do not pass through the highly selective membranes. They remain substantially on the high pressure, or concentrate side of the membrane and become concentrated.

Treatment

The separated permeate is then treated by any of a number of specific processes (including anion exchange, activated carbon adsorption and perstraction) to remove a particular, undesirable constituent. These processes would not normally be considered for treating whole wine because they would be too damaging to other desirable components.

Recombination

The permeate is then recombined with the concentrate and returned to the bulk of the wine. The result is a wine with substantially the same volume and composition except that a specific, undesirable component has been reduced, enhancing the overall quality.

These processes are essentially physical separation processes – nothing extraneous is added to the wine.

The Memstar Process Reduces Wine Alcohol

Memstar AA allows wine to be processed entirely on-site at your winery
The market-leading technology is a proven design based on years of winemaking experience
Only alcohol is removed offering the lowest wine loss out of any system available

• Hire or purchase options available

• • As a cost effective, on-site service provided by our skilled personnel
• • On a short to long term hire basis
• • To be purchased outright (including a license for the use of the technology)
• Systems are available to process 2,500 to 500,000 litres per day, reduced by 1% or more

• Wine processed entirely on-site

• Wine doesn’t leave your winery
• No need for any portion of the wine to be shipped away for further processing
• This means no extra freight costs and less risk of contamination or loss
• Our unique mobile equipment is used entirely on-site by skilled personnel so the winemaker can observe and participate

• Without any water addition

• No water is added to the wine from any source
• Adding water is a practice which is not permitted in most wine producing countries

• No distillation - No regulatory issues

• The process does not involve distillation (high temperature or vacuum) with its substantial infrastructure and energy costs
• It avoids the taxation, OH&S and other regulatory issues associated with the production and handling of high strength alcoholic spirit

• No dilution or degradation of wine quality

• Preserves flavours, colour and tannin
• The wine itself is not heated or evaporated
• No addition of any extraneous material which would dilute wine flavours or otherwise degrade quality
• The process is a closed loop, oxygen free environment

• Minimal volume losses

• Only alcohol is removed in the process so the volume losses are small. In fact for every litre of pure ethanol removed, only about 700 to 800 ml of total volume is lost (a consequence of the different specific gravities of ethanol and ethanol/water solutions).

• Hitting the “Sweet Spot”

• Determine your preffered alcohol level or “Sweet Spot” at the commencement of the process
• Select the preferred amount of alcohol to remove and the plant automatically monitors and controls the job
• Stop the process at any time or go further as you wish
• Perform “Sweet Spot” taste trials as the process proceeds

Taint Problems in Wine

Memstar’s process for salvaging Brettanomyces and bush fire smoke tainted wines was developed and refined in response to the massive problems with grapes tainted by smoke in large areas of SE Australia in 2003 and again in 2007.

Wines made from smoke tainted grapes have a wet ashtray / campfire aroma and a bitter, acrid palate. Similarly, wines severely tainted by Brettanomyces infection are extremely unpleasant with aromas variously described as horsy, medicinal and a finish on the palate that is hard and metallic . The major indicator compounds associated with both these types of taint belong to the group called volatile phenols. In the case of Brettanomyces, the responsible compounds are 4-ethylphenol and 4- ethylguaiacol; and in the case of smoke taint, guaiacol and 4-methylguaiacol.

The Memstar taint removal technology is able to remove much, if not all, of the offensive taint character without stripping the wine of its essential vinosity and character. Since its introduction, millions of litres of smoke- and Brett-tainted wine have been successfully recovered in Australia, Canada and New Zealand.

Reducing Volatile Acidity

Memstar has successfully used its patented VA reduction process since 1997 to reduce the level of volatile acidity (acetic acid and ethyl acetate) in many millions of litres of clients’ wine while flavour elements and other wine constituents remain essentially unchanged.

Excessive volatile acidity still remains a problem, despite the advances in winemaking technology and practice. Wines with VA levels greater than about 0.6 g/l are less appealing to consumers, often displaying estery, glue-like aromas, diminished fruit flavour, and a sour, ’spiky’ acid finish.

High VA can lead to stuck or sluggish fermentations and a product that is, in many cases unsaleable, particularly at levels in excess of 1.5 g/l, when the wine may not be sold legally.

Since 1997 the Memstar VA reduction process has been used successfully to treat wines with VA levels higher than 3 g/l as well as significantly improving wines with even minor reductions from 0.8 to 0.6 g/l.

Why Concentrate?

The Memstar concentration process treats grape juice or wine to increase flavour intensity, colour and body. It does this by using reverse osmosis to remove a portion of the grape juice or wine as permeate.

Grape juice (or must) concentration by reverse osmosis has been used for many years for the removal of water to increase sugar and flavour concentration. It is ideal for treating juices and musts that have become heavily diluted as a result of rain just before harvest. It is a superior technique for alcohol augmentation compared to the addition of sugar (chaptalisation) but has limited benefits where the grapes are green and under-ripe.

Wine concentration after fermentation is the preferred option when sugar levels are already high but the concentration of flavour, colour and other quality components is low. Concentrating the juice in this situation, results in increased sugar levels. These in turn lead to excessive alcohol levels in the fermented wine. Concentrating the wine instead does not increase the alcoholic strength significantly because alcohol passes through the membrane into the permeate and is not concentrated.