Filtration is used at different stage of the wine process.

But why? To rich a crystal clear wine, stabilize it and also protect the wine from micro-organisms the wine normally is filtered.

But how? First it is juice filtration: the lees and visible particles (10-50μm filter). This depends  upon the variety of grapes and the style of the wine that is aimed for. 

There are, then, 3 options. RDV (Rotary Drum Vacuum filter), the most popular, who require patience skill to build this famous « cake «  of Diatomaceous earth, perlite or cellulose (filter media). It’s a Depth filtration type, that ’s mean, it’s not filtrated from the surface, the mode is by absorption and sieve process. The flow is perpendicular or called dead-end. it’s cross the filter media. The inconvenience to have a perpendicular flow is when the filter is saturated, nothing pass anymore. The difference of tangential-flow, who will be along the filter/membrane and can still circulate even if the filter is full of particles. Problems of RDV, it can be time consuming and produces waste(post harvest). During Harvest, sludge can be composted or sprayed under certain conditions. 

Second option is floatation, fast but have to be precise (temperature, etc) to made it works properly. 

Last method is by centrifuge. It is quite expensive by machinery price compare to small amount it can treat

After what ever coarse methods, the wine is still cloudy. Yeasts and other compounds are still in the wine, it is up to 100NTU. We measure the clarity with NTU (nephelometric turbidity unit).

The fine filtration gets rid of yeast and other microbes (2-0,65μm filter). So the wine get transparent, and it can also fixe or prevent some microbial problems. Fine filtration methods includes plate and frame, crossflow and DE filtration.

Plate and frame or pad filter and DE filtration are less frequently used. They are depth filtration type. They waste wine as well a risking cardboard flavor at the beginning. Lenticular filtration also works well but the cost is quite height. These methods all produce a waste stream.

Crossflow, It is the most used, but are different types. It can recently do coarse filtration but do fine particles until 0,2μm so it’s basically reaching the « sterile » point (<0.25μm). The different membranes are ceramic, hollow fibre and spiral wound. It can great to also eliminate bacterias as botrytis, brettanomyces, etc as well as yeast. The machine is expensive, but the labour is not. Low waste, don’t get block, but it can strips the color off and there is no test to check if it is working.

The wine is almost done, let’s get it «sterile». Membrane filtration occurs as the wine is bottled. It is expensive but as crossflow got the most out, the filter most of the time lasts well. There is an integrity test to certify it is sterile. All this, provide microbially stable product.

You can find bottles of wine, who can have visible particles. Can be deformable particles as calcium crystal, after the bottle been forgotten in the freezer. Or it can be just a question of style. A study from UC David (AWRI 2017), show filtration 0.45um, has no consequence on the taste, and aroma. However a style more natural would skip the filtration, because the visual aspect it’s not always the priority. Some winemaker just want to avoid to move the wine too much.


NMIT – powerpoint CC410 filtration 2020

Marketing and wine

It is important to understand the consumer, Wine it is not a service but a product. As it is not a necessity product, we can say it is a luxury product.  To sell it, we have to rise « desire »by either make it affordable for type consumers who look more of quantity, or go for somethings more «unique». Try to convince the consumer of an experience more special. The global production is slightly slowing down in some part of the world, people have more consuming choice. There are more type of alcohol offers, but it is also, sometimes, consumers choose healthier live style and drink less but better quality.

Understanding the market, it is choosing the consumer and deciding the wine style, the marketing strategy and the price range where we want to be on. To look at competitors is important for understanding better the market.


They are determined by different factors

  • Initial value of the product : Grape, additive, labour, infrastructures (rent, maintenance or development), power, aging time and spoilage
  • Marketing value : packagings, features, certifications, times, labours, communications, event, promotions
  • the market location (transport, benefice expected from intermediaries like restaurants, retailer shop, etc)
  • Risk (spoilage transport, not good payer, etc.)

The example of Misha Wilkinson for example, her husband and her target Asia mainly. It is a part of the world developing, with not to many competitors and some trade/business class are wellthy. Their distributors pass mainly by hotel and restaurant, so they offer a while range of wines to have enough styles to match with a whole dinner. They decided to go for small, enough to do most of it by their self and sell quality with a story with it. The wine come from a single vineyard close by a lac, right exposition. They choose the land, they planted the first vine there, they do it with passion…. Must be good, is it not?! Compare to a big corporate who optimize all with quantity and speed to sell wine in bag’n’box…. Both can make profit but have opposite strategy.

So pass the product who is supposed to fit to the market, marketing is also made, to « bring » it to the consumer. Distributors can partly make the job, but it is not always easy to have them as buyer…. So many options are possible in this globalization context. Many « tools » can be used but depends who you want to reach. Website, articles, medals, sponsoring event or business, promotions, innovation, etc. There are limit as alcohol is not an healthy product, each country has legislation who can limit advertising and promotions but I think, creativity is key in this field anyway.


CCO410 Nmit powerpoint

Labelling and legislations

There are generally two ways to make wine labels

One is the «clean front label». Who basically, has the minimum informations (Brand, type of wine, vintage, geographic indication) on the front and the rest on the back label. Has the advantage to be elegant at the first look and also cheaper and more sustainable if the wine is for different markets. The labeling for NZ and Australia would be the same. However, it would need different informations who change according the country of destination. To be clear, the clean front label allow you to keep the front label where ever it is going, and you will have only to change the back label.

The second type is the « single field of vision ».  Who has more informations on the front (net content, volume of alcohol and origin of the country). Those informations are still accepted in many countries, and add space in the back label.

Things who have to be on the label for NZ market: 

  • The brand
  • The word « wine »
  • The type of the wine
  • origin of the country: by NZ laws, it has to be 85% from the country indicated. It’s the same for the 19 geographic indications in NZ or to advise the origin of the block.
  • vintage
  • batch identification on label or bottle
  • sulphate declaration
  • producer (winery or brand or importer)
  • Allergens declaration (milk, milk products, egg, egg products, etc) except for isinglass who come from fish 
  • Standard drinks
  • Alcohol by volume

Promoting the « health » sides of alcohol is prohibited. To prevent excessive alcohol consumption some marketing strategy really have to be think twice and choose the right word. For example, you can right « lower on alcohol » but not « low alcohol ». Discounts can’t go up 25% etc. However warning logos of the pregnant woman, and cheers are optional in NZ at the moment…

Some special wines as sparkling, sweet, hight on alcohol wine have other rules proper to their category.

Oversea rules are so different so it’s better to check it with the importer of the country. It’s charing the responsibility as well. Rules are going from labels in other alphabet, to health warning sentences, to size of typo, to certificates, different tolerance of quantity for alcohol, indications, etc. A Wine Labelling Guide is available from NZ Winegrowers.


Wine labelling guide- NZ Winegrower

Biodiversity wanted!

Globalization is crazy. On one hand, it’s giving us more easy and affordable access to diversity of wine. We can easily find a wine from each continents, but which type of wine? I personally never saw Grolo on shelves around here, or whatever variety of grapes who are under the 20 most popular varieties in the world . Some varieties are just taking over! Cabernet Sauvignon, Merlot, Tempranillo, Chardonnay, Syrah, Grenache Noir, Sauvignon Blanc, Pinot noir , Ugni Blanc, etc are some of the top varieties. They have advantages to have be adapted to a while range of climate, to be disease resistant, or/and hight crop production with taste and aroma characteristics. They also won on reputation, than consumer are expecting its. It is then, an easy market for all of those. However, it does bring an homogenization of tastes and landscapes. It could be so much richer, knowing than it is existing more than thouthans varieties in the work! There are about 1300 types of wine grapes just for the white wine( And they can not be that weak as they been developed and cultivated for centuries to get 4 caracteristics: (

  – Production: resistance of vines and adaptation to the climat. Selection of sizes, aspects and quantity of berries and grapes. 

  • Fermentation factors: Sugar level, moderate acidity
  • Pigment composition for flavor and aroma
  • Colors

It would also more sustainable to diversify, rising the genetic diversity in areas the other model is fragilizing agriculture. 

The problem is probably culture and economical. 

For example, France is the 2nd country producing wine in the world and also second consumer of the global consumption from IOV 2020 report. Few hundreds of wine vine exist there. They exist and been created by culture and traditions. The fact than French people are drinking a lot their own wine make, probably it worthy. However in the other hand, France has 43% of its production are of the top 10 of varieties of the world, because they also export (3 positions). There is sort of a balance who can be report it to Spain, Italy and Germany with different proportions

The New world is quite different. For example , New Zealand produce way more than the national population could even drink. Even if we stop beer and gin! So because New Zealand production answer more to an export market, it is more about investment than cultural taste, so the risk to explored new markets by trying « minor » varieties is unlikely an economical futur. 91% of our production is from the top 10 varieties. There is also the factor than NZ wine is selling for more over see than is it own country….

It is unlikely than this model will change, but it still at individual scale possible to either drink local or just be more curious about things that we don’t know and open new markets.


Bottling logistic

Where I work, we bottle our wine mainly on site. The person in charge of the production is always playing between budget and delay. Once you have your brands, not much changes from one year to another, but you can not buy pallets of bottles, cardboard, caps, palettes for all year. It would be a lot to storage need and empty spaces a the end of the year. You also need an insulated warehouse to regulated the temperature once the wine is bottled. There is the cash flow to consider . Suppliers offer reduced prices, for bigger orders, but it is a lot of money to get out in once. It would include storage, workers at the bottling line and wine who take more space after than stored in a tank. 

We have all our bottle already chosen. We follow the traditional choice which is the glass bottle. It handles the pressure of the CO2, there are affordable options around sizes, shapes and colors. It is made partly from recyclable glass and can be recycled again. Standard types are made locally for reasonable prices. Inconveniences are the weight, the volume for transport and the fact that is breakable. A more customized bottle will bring the cost up and probably will be also longer delay to receive it, as it will come from overseas. There are other options like bag’n’box, cans, kegs, etc, but there are currently minor.

Once the bottle is picked, the person who manage the production is on the hurry to know the alcohol level to finalize labels. But she can have different labels, depends on the destination, but it is hard to predict how much each country will buy along the year. It is where, it is interesting to do a clear front label. We can at least have a descent order of front one and have several small order for the back label. A big part of labels are not made locally made (USA), and every effect (like foiled, etc) will add suppliers, cost and delays. Some shapes are also harder when you calibrate the labeler and it can have waste.

Closure are 70% aluminum of screw cap in NZ. Made of recyclable material, cheap and quite reliable compare to cork. Lux cap involve labour and tool cost. Vinoloc are good and elegant but expansive….

We personnaly design our cardboard box like many : without vintage and print it when just before they go on pallet. We can use them a year to an other. But there is still the dilemma of the complexity of the box: 6 or 12 packs, divider included or not, etc. 

On a side, there are tapes, plastic pallet wraps, and pallets stock to look at. Wraps can be recycled and will require storage and logistic. They are different types of pallets. They can worth money, so it is important to spend time on logistics. There is the blue empire, CHEP, who are used around the world and are in a loop as where ever they goes they can be reuse. CHEP fixed them if need it. Other (Arora, Charta) use the same reusable rincipe but at different scales 

The idea with a bottling plan is to leave the wine as long is possible in tank and playing with true orders and order predictions, delays of production and deliveries and cash flow. It is a big job, but it is saving us money and giving flexibility. Bottling companies offers more bottling options but they are more expensive, the wine get an extra transportation and they require more times for booking.

Sometimes, it is worthy to have a bottling plan close by the consumer and send it in flexi or Iso tank. It is saving on weight and volume during the transport, and suppliers can be closer, but it is hard to control the quality at the same time…


winework – powerpoint

bottling and packaging powerpoint

Work on a bottling line


Depends on the characteristics of the wine first. Variations by the type of wines and varieties of grapes occur, but for our classic Sauvignon Blanc, it is normally filtrated, free SO2 at 30ppm and CO2 around 1.4g/l, Alcohol, density and Do are also double checked

The bottling line is cleaned like a tank. Caustic and citric run through it (except the filterer) and sterilized with hot water. 

Running : 

Each first bottle of each filler head is take it out, in case the wine is diluted with the water who been use to rinse the line.

Then the following bottle is taste and approved by a winemaker. We put 2 samplings bottles a side, one goes to a lab to check the sterility of the wine. The other stay in the archives as long the wine is on shelve in case there is a complain and we can double check it. Wineworks archive a bottle every hour for each line. A check will then occur from the start and every hour: Speed of the pump, pressure at the filter, at the « snow » and at the head fillers tank, the aspect of bottles, all rinser heads and filler heads, snow dropping, caps correctly screws and thread, label positioning, lot number correctly printed, aspect of cardboard box and correctly printed.

Few records are running around: number of the Item, batch and time of bottle pallets, caps, wine pallets.

Terminal phase:

Once the pallet is wrap it can be dispatch at the right destination.

At the end of bottling, the wine is pushed with nitrogen to avoid dilution, the bottling line can be sterilized again and the area cleaned 

The person who supervise has to be qualified as the machines are not fully reliable and every problems are generating wastes of packagings, time and money. There is also a big responsibility of safety, quality and equipments.

Traditions and appellations

Appelations are made to respect traditions and guarantee a « savoir faire » of an area. Depends where, but it can certify grape varieties, ripeness and alcoholic strength, viticultural practices, yields and winemaking Practices. Because Europe is old on traditions, each country had their own certifications before E.U been created. They most of the time are writing in their own language and have specific rules. It does involve a bit of time to know what include each appellation rules as they are so diverse. For example, Bordeaux includes 60 AOC in 9 975,6 km2. Marlbourough by it self, is 12 484 km² and only one GI…..

Here are few specificities of the old wold:

Europe appellations who include all those particularity:

  • Protected designation of origin (PDO) : 100% produced, processed and prepared in specific area. Quality and properties due to a partial environment. Its obtained from vines varieties belonging to Vitus Vinifera only.
  • Protected geographic indication (PGI) : 85% produced, processed and prepared in specific area.
  • Wine : Do it how you feel!


  • Main appellations are :
    • « Appellation d’origine controlée » (AOC) or « Appellation d’origine protegée »(AOP) = P.D.O
    • vin de pays=PGI), vin de table VdP = VGP(vine)
  • There are different classifications by area : Grand, premier cru, village and regional appellation are appellations but « cru bourgeois » for example is more like contest and the classification can change according years.


  • Qualitätswein (QbA) and Prädikatswein are PDO terms: those PDO are classified based on ripeness harvested grapes and vine style
  • PGI are Tafelwein and Landwein – VDP (Verband Deutscher Prädikats- und Qualitätsweinguter) it does work like French Grand, premier cru, village and restate classification


they have 2 PDOs: « Denominazione di Origine Controllata e Garantita » (DOCG) and « Denominazione di Origine Controllata » (DOC).

  • DOCG is really easy to identify as they have a specific seal for proof of approval. The wine has to pass a tasting panel.

PGI is either « indicazione geografica protetta » (IGT) or « indicazione geografica tipica » (IGT)


Same as Italy and France, 2 appellations can fit under PDO : « Qualified Denominación de Origen » (DOCa)  and « Denominación de Origen Protegida » (DO) 

Spain has the specificity to include a minimum aging in the winemaking criterias

PGI is vino de la terra

All those regulations are supposed to protect consumers, and sort of guarantee a certain quality. However, good wines are hidden every where! Sometimes producers decide to not follow those rules and skip the appellation, but doesn’t mean they have no ethics…. For example, a viticulturist in « Côte rôtie » can still work properly but grow something else than Syrah or Viognier. a Beaujolais producer can have good practices but decide to machine pick, etc…. 

Colloidals and filtration

NTU in filtration

the clarity (unity=NTU) is measured by how much light is passing through a certain amount of liquid. It see suspending particles in the liquid but doesn’t say how big they are…. Roger Boulton published in 2001 an article « fouling of wines on membrane filter is not related to the clarity » it show studies who demonstrated wines at the same turbidity who are not fouling filter in the same way or higher NTU is fouling less the filter than smaller TNU in some case. It depends of their compounds. For example, if they are very thin and in hight number, they will build a more compact layer as retenante than bigger particles with less quantity. It is a bit like clay and sand. Sand will still let pass through where clay doesn’t. But in the bottle they can have exactly the same clarity depends of quantity. The problem are the colloidals in the wine.

Enzyme friend of filtration

Enzime can be part of filtration process, and because it is chemistry, it sound way more exiting than filtration to me. Sure people get very chill about enzyme as it can change the taste of the wine very easily but depend the type and the quantity used. Most of enzymes are naturally on the vine and it can be the wine when the grapes are crushed with stems.

Polyphenols can basically connect with other things. They build chains and hold goodness as retentates when normally those would pass. In some case it is possible to push them through with a bit of pressure but it is not ideal, and it can strip out the wine. Sometimes just the time break them apart but it can build up again later. Enzyme is the third option.

Some varieties can be very rich on colloidals, and it is obvious than this problem will appear. So an addition before alcohol is created, would make it more efficient. If the fermentation already started, then the addition will be after as it drop the yeast out. Some type of colloidals can also appear during malolactic fermentation. They seems to come out easier when they are at cold temperature

Enzymes can change the taste as it is changing the structure of the wine (not always in a bad way!), it also need time to stabilize. It can happen than the wine change and look strip out, but few week later, good flavors can express their-self again… Once the structure been change, the NTU can goes up but the filtrability is way better.

I still think NTU give a brief idea of which filtration type to use (if we have options), however colloidals can surprise us and make filtration harder.


AWRI ( 2017) Factors affecting wine texture, taste, clarity, stability and production efficiency. Retrieved from: /rde-plan/projects/project-3-1-4/  

Gases in wines

First of all, gases are naturally present in wine. Once pressed, for all wine’s movement, it will pick up oxygen(O2) and create Carbon dioxide (CO2) during fermentation.

Oxygen can be very beneficial to boost stunted fermentation, softening astringency, improve tannin, stabilizing color and get rid of some reduced smell. However, it can also be the cause of 3 types of oxidations : enzymatic, chemical, microbial. 

Enzymatic oxidation is produced by polyphenol oxidase and laccase. Both makes the SO2 unstable.

The second one is chemical and would react with phenol, change color (browning), losing aroma and bringing some reduced smell and taste

The last one is microbial oxidation and would feed bacterias, yeast and microorganism who can spoil the wine as acetic acid, acetaldehyde, ethyl acetate, etc

Those problems push to use Oxygen with care and moving or storing wine post fermentation with the minimum of contact with it. It is why (DO) has to be monitored frequently until the wine end up in a bottle. Using an electronical membrane sensor, a luminescent/optical sensorProbe or a luminescent with sensorspot allow you to check it. The big differences between those equipments would be speed, accuracies, if the probe have to be in contact with the wine or not, if it is fit in a bottle or just for tanks, and of course prices. Excess of O2 can be sparge with Nitrogen. Temperature is one of factor who has quite consequent importance with it. The wine will pick up more oxygen at cold temperature and releasing it better at hot temperature.

The second Gas mainly used is CO2. Depends of the characteristics of the wine, but it can enhance fruit flavor and bring some freshness to a white wine. However in red wines it can increase harsh textures and tastes in reds. So we impact on the style wanted, from somethings quite flat but with strong tanins to something fresh as sparkling wine. Sparkling wines have actually different methods. The gas can be 100% from the fermentation, directly the bottle (champagne style), or be manage in tanks with a pressure gas system, and sparge of one or different gases (Oxygen dioxide, nitrogen and/or argon). The level can be measured with a carbodosor and the excess can be remove by sparging Nitrogen or using a membrane contractor vacuum. Some factors have to be considering for the solubility (Temperature, alcohol, carbohydrates, phenols, proteins)


NMIT powerpoint- oxigene management


Sulphur compounds are used sometimes in the vineyard to prevent powdery mildew and a bit at the pressing for antioxidant capacity.  Problems if there are not enough amino acids or nitrogen in the juice, yeast will create, during the fermentation, volatile sulfur compound (sulphides, H2S) as a by-product of amino acid metabolism. More they stress, more they produce!  No one want sulphides. Its is creating bad smells and pre-age the wine, and what a process to get rid off it when you have them! The wrong solution can even make it worst….

Four types exist. First H2S. It is the easiest to get rid off, as it is volatile: a bit of oxygen would be enough. This action has to be soon as the rotten egg smell appear. If you leave it for too long, it could be already transformed to the second type: Mercaptans. Then, the oxygen would  « feed » it and it will become the evil and sneaky di-sulphide. Why don’t you want di-sulphides? Because it’s harder to get rid off it. There are 2 sub-types. The type DMDS, once comfortable in the bottle, it will express some onion and cooked cabbage smell. The other one, DEDS, will have more burnt rubber and garlic notes. Lovely! Dimethylsulphides (DMS)are the last sulphides of the list. You can not get rid off it and it get most of the time detected at the final stage. The consuming stage! we can find it in aged wines. It can be nice at small dose as it can bring some blackcurrant and jam caracteres for reds, but it can also bring unplaisante vegetals test (asparagus, cooked corn, etc)

So if mercaptans are already in the wine, a copper addition will do. However, if it is too late and di-sulphides are already in the place, copper won’t change anything…. To « reverse » di-sulphides to mercaptan, it needs first ascorbic acid addition, and then, treat it with copper.

To be sure to know which type of sulfides you have in your wine, it’s better to do a trial with different fining agents: Copper, cadmium, ascorbic+copper. 

I find the chemistry of those compound incredible, how we can go forward, and reverse… and forward again… but until a certain point. Sparging O2 or using too much of ascorbic acid can oxidase the wine. Copper also has to be manipulate with care and be added the best and minimum amount to don’t spoil the nice aromas existing.

However, if it’s a bad year, and sulphures will be in quantity from the start. There are few alternatives to prevent all this « hide and seek game». Commercial yeasts produced less HO2 than some wilds. Feeding the yeast of DAP and nutriment at the right time of the fermentation if YAN is low. Control the temperature for a fermentation nice and slow and not stressed yeast. Be sure than the fermentation is finish when you add SO2. As sulphides are sometimes in the lees, racking early can allow decrease the amount in the wine too… if too early, maybe clean lees from somewhere else can be used instead.

Good luck!


NMIT powerpoint