Making wine

In the following:

  1. SO2 means potassium or sodium metabisulphite - commonly available as campden tablets (ct) - or SO2 gas if available.
  2. Gallon is used interchangeably with 5 litres (4.5 litres is more accurate).
  3. Carbonate means calcium carbonate – sometimes called precipitated chalk.
  4. Suss (or suss reserve) means fruit juice retained for sweetening.

Tips

  • It is useful to have a variety of storage vessels of different sizes.
  • Keep all bottles and vessels clean and sterile.
  • Harvest grapes and crush (i.e. break the skins) or if you have the luxury of a destalker (sometimes called destemmer) or a very small quantity of grapes that can be destalked by hand you may prefer to destalk white varieties rather than crush. For red wines it is considered very much better (or even essential) to destalk as the stems can flavour the wine during the maceration process.
  • Check the sugar content of the juice with a hydrometer or refractometer if you have one.
  • Press white wine grapes at this stage; (for red wines, see below)
  • For white wines, transfer the lot to a storage and 99% fill the container to exclude air. (Note this is where a planned harvest or a variety of vessel sizes is important.)
  • Kill any wild yeasts in the juice with SO2 - 1ct per gallon, minimum.
  • Stand white juice overnight or for 24 hours to settle out the pulp – use air lock and if possible exclude air by blanketing with CO2.
  • For white wine, rack off the clearer, upper layer of juice and transfer to the fermenter. Transfer the bottom layer of pulp to a small vessel which should be completely filled. Add 2 ct per gallon to this and allow it to settle further - this will produce a clear juice that can later be used to sweeten the wine, if necessary - this fraction is called ’suss’ following the German for ’sweet’ as they are credited with inventing the practice.
  • For red grapes, hand-destalked berries may optionally be crushed. The juice and berries are then transfered to a bin which should be substantially full and covered with lid to keep out contaminants. The mix then undergoes the process of maceration’ during which the juice extracts tannin and other chemicals from the skins and pips - and from the stalks if the bunches were just crushed. (Note that stalks and pips contain more tannin so crushed grapes should produce a more astringent wine.) If all the wild yeasts are not killed, fermentation will commence and CO2 will be generated.
  • If a polythene bucket with a tight fitting lid is used, an air lock should be added to allow the CO2 to escape.
  • During this process some berries will float to the surface and form a ‘cap’; this needs to be pressed into juice with a potato masher or a similar tool. Do this at least every second day or more often. When sufficient colour has been extracted transfer to the press and separate the juice from the skins and thence to the fermentation vessel.
  • Note that if SO2 is not added initially, the wild yeasts present on the grapes will start the juice to ferment. If the berries are no crushed the process is called ‘carbonic maceration’ and is a deliberate ploy when making certain types of wine - such as Beaujolais. This is not recommended with a new vineyard as the ‘good’ wild yeasts may not yet have moved in while some ‘bad’ ones will almost certainly be there.
  • Rosé wine is made the same as red with perhaps a one day maceration period rather than 5 to 10 days for red.
  • If necessary, adjust the sugar level by adding cane sugar before starting fermentation - download ‘WineCalc’ to help you calculate the correct quantity of sugar.
  • Add yeast, following the instructions on the packet; fermentation should commence within a day or two.
  • If you have a lot of juice, a starter bottle is used. About 5% of the juice is transferred to a bottle which should be about 70% full. Yeast is added and the bottle is covered to exclude dirt but not air. Under this condition the yeast will grow. After a day or two when the yeast fills the juice add an air lock. When fermentation starts, the starter is returned to the main body of the juice where fermentation continues under air lock. If more than one fermentation vessel is used, divide the starter in proportion to the contents of the vessels.
  • Do not fill fermentation vessels to more that 75 to 80% of capacity as frothing may carry the juice/wine through the air lock.
  • Use sterilising solution in the air lock - this helps to keep oxygen out.
  • When fermentation is complete and the yeast has settled, rack the wine into a storage vessel. Add SO2 - 1ct per gallon. Make sure the storage vessel is brim full and add a pinch of carbonate. Store under an air lock and leave the wine to clear.
  • Store the lees (i.e. the residue after the wine has been racked off) in a separate vessel – brim full; add SO2 - 2ct per gallon – and a pinch of carbonate and store under and air lock or better yet a one way valve such as a safety cork if you are using demijohns or a BetterBottle dry air lock if you are using carboys.
  • If the wine fails to clear you may need to use finings.
  • If available, coarse filter the white and rosé wine when it appears clear.
  • Rack the suss when wine and suss are both clear.
  • Blend a small trial batch of suss and wine to find the optimum sweetness. (e.g. add suss to achieve ½% sugar; if insufficient try ¾% and so on).
  • Blend the wine to the preferred sugar level and sterile filter immediately.
  • Fill storage vessels brim full and add SO2 - ½ct per gallon and leave to age.
  • Bottle.

Important Note

If you blend wine and suss and do not have a sterile filter there is a risk of further fermentation even if only a trace of invisible yeast it left in the blend. A wine that looks clear is not necessarily free from yeast and the only safe way to use this procedure is with a sterile filter. If you do not have a sterile filter it is safest to stick to dry wine but this may not be to your taste
If you risk sweetening without sterile filtration, add SO2 - 1ct per gallon – and a pinch of carbonate. Store the blend under a one way valve or a safety cork (or an air lock as a poor second) as a precaution against further fermentation. Bottle as late as possible before drinking to reduce the risk of the bottles exploding. You can also use sorbate as a preservative. If possible, delay blending until just before drinking as this minimises the risk of explosion.

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