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The cellar is built next to a table-grape packing facility.
This means that we have an unrivalled refrigeration capacity, as the table grapes are only processed for eight weeks of the year, and the end of the table grape season dovetails with the start of the winemaking.
Before de-stemming and crushing, hand picked grapes of red and white cultivars are cooled to 0°C in the same cold rooms used to chill the table grapes. The low temperature of the crushed grapes makes it possible for us to avoid the use of sulphur dioxide (SO2) at this stage, as low temperatures inactivate bacteria and yeast.
Machine harvesting takes place in the early morning when the grapes are at their coolest. If additional cooling is needed the grapes are pumped through a mash chiller.
White grapes are separated from their juice before fermentation and the juice is cold settled to clarify it. We also have the ability to clarify juice quickly by means of flotation with inert gas. This is especially useful when power outages threaten, as one only needs an hour of power supply to inject fine bubbles of nitrogen. After that the bubbles rise through the juice taking solid particles attached to them to the surface. The clear juice is then drawn off from under the foamy cap that forms. A selected yeast culture is added and the wines fermented below 15°C to retain a fresh fruit driven style.
Much use is made of the protection afforded by yeast lees (the yeast cells that settle on the base of the tank after fermentation). These lees are stirred regularly and protect the wines from oxidation as well as contributing to the balance and mouth feel of the wine. When it is time to bottle, the wine is made protein-stable with bentonite and cold stable by chilling the wine close to its freezing point to allow the potassium tartrate crystals to fall out of the wine. The wine is sterile filtered and bottled with a filling machine that replaces the air in the empty bottle with inert nitrogen. This gives maximum protection to the wine from oxygen during the filling operation.
Red grapes are also cooled before de-stemming and crushing. This allows us to achieve a "cold soak" for a few days before fermentation starts. The low temperatures take the place of SO2 in inhibiting the growth of wild yeast and bacteria. Cold soaking is the steeping of grapes in their own juice without fermentation. The red pigments are water-soluble and immediately start coming out of the skins and into the juice. At the end of this soaking period the juice can be as dark, or even darker than the finished wine. The alcohol and heat from fermentation is not needed to extract this colour. The darker juice and grapes are then allowed to warm and are then inoculated with a selected yeast.
Temperatures are regulated to around 250c. This provides an optimum temperature for the yeast. Each tank is connected to a computer that regulates the flow of cooling fluid in their double jackets.
Tannins and phenols are responsible for the astringency and mouth feel of the wine. These components are extracted from the skins and seeds and the heat and alcohol from fermentation hasten this process. Having already extracted the colour during the cold soak one can press off (separate) the skins from the wine before the end of fermentation when the tannins and phenols have reached the right intensity.
During fermentation the skins rise to the surface with the trapped carbon dioxide and form a cap. The skins need to be kept in contact with the juice. The conventional way to achieve this is to pump the juice from under the cap and let it flow through the skins back into the wine. However, we make use of large bubbles of air, introduced at the base of the tank. These large bubbles have a strong lifting force and mix the skins and juice very quickly. We insert a stainless steel lance through the cap and use compressed air that passes through an air and oil filter. The advantages are that it is a much gentler operation. There is no chance of crushing skins and pips in a pump impeller. It is quicker and more hygienic. Sceptics worried about the introduction of damaging air into the wine should remember that a bubble that breaks at the surface has not dissolved any air into the fluid. In any case a strong ferment needs a lot of air and one of the reasons for pump-overs is to introduce oxygen. Towards the end of fermentation or even if one is doing a post ferment maceration, stirring can be achieved by using nitrogen gas from our nitrogen generator.
The pressing of the grapes is done with two Bucher XP 150 Ortal Flow Presses. These are amongst the most modern and sophisticated presses available in the industry. They ensure maximum yields of top quality wine and juice.
Wood can be used in different ways depending on the style and price of the wine. One can make use of chips during fermentation to stabilise colour. The wine can also be fermented with staves installed inside the stainless steel tanks. These methods are the most environmentally responsible as they make the most efficient use of a tree that was almost one hundred years old when it was felled. The last, most expensive and most traditional method is to use barrels. These are used on our flagship range: The Sensory Collection.
These are wines produced without the addition of sulphur dioxide at any stage of the winemaking process.
Sulphur dioxide is one of the oldest known food additives and has been used in wine since ancient times when sulphur was burnt before sealing the wine in the barrels. It also develops naturally in wine as part of the fermentation process.
However it is also added as a preservative to prevent oxidation of the wine and at the grape-crushing stage as a cleansing agent to kill unwanted bacteria and wild yeasts.
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Organic refers to a system of farming that maintains and replenishes the fertility of the soil. The grapes are grown without the use of chemical pesticides, herbicides, fungicides, or fertilizers.
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Only compost and organic materials are used, with indigenous vegetation for mulching.
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Weeds and pests are controlled using environmentally sound practices that sustain the health of our planet and ultimately our own well being.
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In the cellar the maximum allowable quantity of sulphur dioxide is half that of the maximum permitted for conventional wines and certain chemicals are forbidden.
We are committed to the principles of organic production and our dedication is shown by the following:
- The winery is a processing facility and its task is to maintain the organic status of the grapes during the production of wine and to do so in an environmentally responsible manner.
- Where possible waste products are recycled or reused. Skins from the press are composted and plans to make organic grape seed oil are well advanced.
- Water usage in the cellar is audited. Water has the solids screened from it and goes through aeration and an effective micro-organism treatment (EM), before being used for irrigation.
- Chemicals for cleaning and for use in winemaking are kept to a minimum and alternatives such as steam are used where possible.
- Wine is at all times recognized and respected as a natural product and additions and manipulations are therefore kept to a minimum so as not to compromise the integrity of the farms, the cellar and its products.
The organic policy is formally reviewed before the start of each crush, and is open to review on an on-going basis.
Stellar Winery is supervised by Control Union Certifications, an organic inspection body accredited by the Dutch Accreditation Council RvA, whose very strict production criteria must be met for organic certification. Our Certificate of Accreditation number is: CU 021 094
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