GUIDES

EDWG Country WineMaking Course Notes Download these notes in pdf format.
Grape Winemaking.......Sparkling Winemaking

Grape Winemaking

Written by Stan Gower
Thursday, 31 December 2009 09:12

Picking the Grapes...Crushing...De-stemming...Pressing...Adding Yeast...
Adding Yeast Nutrient...Racking...Oak...Fining and Stabilisation...Bottling...Rewards!...Acknowledgements...Contributors Page

Introduction
This guide is written with the beginning, SMALL SCALE, HOME wine maker in mind and is an illustrated, master document tying together the wine making process described by other EDWG “summary” articles. You will notice some text coloured as follows, red wine making process; This is a link to another document. You can either read on, or click to be taken to another document for a more complete explanation of the concept or process.

Wine Making is a process beginning in the vineyard. This guide starts you off at the point where you pick the grapes and takes you through the individual steps to finally get your precious wine into its bottle.

The Guide presents low cost, sometimes home built equipment so that the beginner can get started with a relatively small financial commitment to expensive equipment.

It's true that wine making is a combination of practice, art and science. One selects the material based on its perceived qualities, then tweaks it based on measurement and taste. All the while you make sure that, through good practice and knowledge, only friendly microbes and yeasts visit your wine. You may give the process gentle pushes and nudges to protect it from microbes, enhance characters that are already present. You take particular care to make sure that the finished product will last for a reasonable time in the bottle until its finally consumed by you and your impressed family and guests.

There are some important differences between making red and white wines. Red wines are fermented with the skins and pulp. The whole lot is then pressed after the fermentation is complete or near complete. White wines on the other hand are normally fermented as a clear juice. That is, the grapes are first crushed, pressed with the resulting juice clarified lightly before fermentation is commenced. The Guide will point out other specific differences.

You may find it useful to refer to the diagrams summarising the red wine making process and the white wine making process.
PICKING the grapes (is a fun way to start making your wine) ... ^
The Eltham Winemakers' Guild has a web site set up (EDWG Winemaking Fruit Sources) early in each year for vineyards to post grape availability to Guild members, including type of grape; expected ready date; and price per kilogram, either picked or pick your own. The buying is then arranged directly between the wine maker and the vineyard.

Bulk grapes can also be bought at markets, but for a beginner it can be difficult to assess the grape freshness and quality, as these grapes often come down by truck from Northern Victoria; may have been sitting in the vineyard in boxes and on a truck for 5 or 6 days before they get to market. They are generally cheaper than grapes directly from the vineyard.

Good wine begins with good grapes, so if you are not careful you simply will not be able to make good wine no matter how careful you are in actually making the wine.

You will maximise your possibilities of making good wine if you buy good grapes from a reputable grower. Such growers will advise you on the fruit's ripeness in terms of its sugar (Brix) and acid content (pH).

grapepic   As a guide, red grapes such as Shiraz and Cabernet Sauvignon should be between 24 to  26 Brix with a pH between 3.4 to 3.7

White grapes such as Sauvignon Blanc and Chardonnay should be between 18 to 23 Brix with a pH between 3.0 to 3.4

pictured...PICKING CHARDONNAY GRAPES
 

Pictured ...RESTING OVER LUNCH

 


Diseased grapes... ^

Some of the issues when selecting healthy grapes when picking are: dried out grapes; severely bird pecked grapes; Botrytis mould or rot, see picture below; grapes that are past their prime, being picked too late after being ready.

 

 

 

 

Pictured ...DESEASED GRAPES


CRUSHING THE GRAPES
In early peasant wine-making, the grapes were crushed by stamping on them in a vat, after, hopefully washing your feet.

Modern machine crushers combine crushing AND de-stemming the grapes, all in one process.

  Destemmer Crusher

For the small wine maker, to buy a crusher de-stemmer would not be very cost economical.

They can be hired, but the time to book it when needed, when other people need it as well, to hook up a trailer and drive to collect it; use it within the time booked; clean it, and return it all takes a lot of time.
For quantities of grapes of 300kgs to 400kgs, or more depending on your energy, a hand operated mechanical crusher is less expensive, ($450 new, to $150 second hand if you can find one is a practical and convenient alternative. See photo below

One way to mount and operate the crusher is to wash and sterilize two wheelie bins about the same height. One bin, as in the photo, sits on one bin to collect the crushed grapes and juice. To allow getting the crush out of the bin, it is easy to slide the crusher out of the way onto the other bin standing alongside.

It's essential that the crush be sulphated.

 See the Summary article on PMS/SO2. Also see the Summary article on Oxidation.
 

Crushing....^

SAFETY. Use a block of wood to push grapes between crusher rollers. Some manual crushers have a "wavy" bar that rotates in the grape bin to help the bunches fall through the crushing rollers. The crusher pictured does not have that, so the bunches of grapes need to be pushed in with a piece of wood, to prevent risking crushing the fingers.

  NOTICE the small amount of PMS per 10 kgs of grapes
A GENERAL RULE. Never add an extra quantity of a chemical just because there seems to be a need for it, because, once added, you can't take it out again if you have made a mistake. Only add after you are sure that the additional amount is correct, and needed.

Pectic enzyme, when making WHITE WINE only.
at rate of 10 mgs per 100 litres of juice = 50 mgs per 1000 Kgs grapes ( 30 - 50 mls / ton.) = 10 drops (from eye dropper) of enzyme to 10 kgs of grapes = 1 drop (from eye dropper per 1 kgs grapes.

 

 Enzyme Crush

1 drop from an eye dropper per 1 kg of grapes

= 10 drops for the 10kg hopper of this crusher.

 

   

De-stem.... ^
The crushed grapes need to have the grapes and juice removed from the stems, and the stems discarded.

  Getting crushed grapes to de-stemmer tray

As mentioned above, a crusher de-stemmer does all this as the grapes are crushed
 

Vigorously stroking fingers back and forward through grapes releases grapes and the stems "float" to the top for removal.

NOTE RE: BIG CONTAINERS. Council wheelie bins are safe for crushing grapes into and for fermenting wine in up to the pressing stage, PROVIDED they are thoroughly cleaned and THEN sterilized BEFORE use.

Pressing ... ^
For WHITE wine, the grapes are pressed immediately after crushing and de-stemming

For RED wine, pressing is not done until after yeast fermentation is completed. If Malolactic “fermentation”is progressing at this time, that’s OK because it will continue on after pressing

  Left...Basket Press

Some are made of Stainless steel

 

Right....Pouring de stemmed
Grape Juice into the home
made basket Press.

 


 

  A lever off veranda post provides pressure

to squeeze juice from the crushed grapes

 


Processed 116 kgs of grapes on yielding about 49 litres of juice.
A fairly poor yield. Unfermented white grapes seemed to be harder to press than fermented red grapes.


 
Left...
Collecting the juice from press tray.

 

Right...
This is what's left from 180 kgs of grapes.
 

   

Adding yeast to the grape juice....^
See the EDWG Summary on Yeast Fermentation.

Only use fresh yeast bought from a reputable supplier.

If acid is to be added to adjust pH, leave that addition until the fermentation is well started in the juice containers. This is usually well noticeable by listening close to the container to hear the small bubbles “crackling.” If the yeast is hard to start, have the pH checked because this can sometimes inhibit the yeast start up. See the EDWG Summary article on pH/Acidity.

PREPARATION of Yeast in small plastic containers with 100ml of water at 38'C
Sprinkle 4.5 g of yeast in each one ...
Stand containers in water at 38'C for 25 minutes
 

Digital thermometer. Water in tray @ 40'C to keep water and yeast and sugar in small containers @ between 35'C and 40'C

- Put a pinch or two of sugar in with the yeast and water at 35-40 degrees.
- Now the rest is patience. After 20 minutes or so by time it should be foamy, leave the jar on your bench at room temp or less and let it cool.
- Gradually add a few mls of the grape juice (called must) every few minutes to hurry the temp drop, adding only with the foam remaining strong (wait otherwise). As the activity increases (helped by the small doses of must) you can add larger amounts of must.

- Bring the temperature of yeast suspension to the same temperature as the must.

- When using open top must containers, this can be done by floating yeast containers in the must until the temperature of the yeast suspension is the same as the temperature of the must. If the must containers do not have a large enough neck to float the must containers, then float the yeast containers in hot or cold water until their temperature is the same as the must.

- When yeast foam is more than 50% of the total volume, and its temperature is the same as the main juice, then pour yeast solution into the juice and stir in.

  Ready to go into the must.

- While fermenting, bring temperature down to about 16'C to 18'C.

This is important for flavour and nose of wine.


ADD YEAST NUTRIENT...^
See the EDWG Summary on Yeast Fermentation.

CHECK FOR Hydrogen Sulphide. (Rotten egg gas!!) smell while fermentation is in process, it is necessary to. This must be treated early, otherwise it can become a very serious fault that is almost impossible to fix.

FOR RED wine, Press after yeast fermentation is completed, and enough colour has been extracted from the skins. Also, see the EDWG Summary article on Malolactic Fermentation.

RACKING ..^
See the EDWG Summary article on Racking

Racking is simply syphoning the wine from one contained to another clean and sterilized container.

  AFTER yeast fermentation is completed, the wine needs to be racked, three times, about a month apart.

When the top container is nearly empty there will be some sludge of grape pulp and other residues at the bottom.

These are not syphoned off, but washed out with clean water, and then that container is used to receive the next container of racked wine.

 
   

Left...DemiJohns between Rackings
The wine is kept in containers with air locks filled with water to allow CO2 gas to escape, but stop air getting back into the wine container.

 

Right...HOME MADE lifting frame, (then slide small table underneath) to help with both racking and bottling.

 

OAK.
See the EDWG Summary article on Oak.

Fining and Stabilisation
For white wine, consider adding Bentonite. See the EDWG Summary article on Fining and Stabilisation.


Bottle Sterilisation, and filling....^
See the EDWG Summary article on Cleaning and sanitation (sterilisation).

  1-Bottle Tree

2-Bottle Filler

3-Bottle Corker

 

1- Bottle tree is to drain the sterilised bottle
The diaphragm regulator on the Right is for filling bottles. It cuts off the flow of finished wine when the bottle is full.


2-Pump on the center squirts PMS, (Potassium metabisulphite) solution is pumped into the inside of the bottle to sterilise it, (after it is cleaned by washing with bottle wash if it needs it).

3- Corking machine ...The following EDWG summary articles describe the basics of cork care; airlocks and bungs; and Measures, quantities, units and are also highy recommended.

  Reaping your reward    ^


This is what all the work was for!!!

Stan Gower enjoying his own wine.

 

Acknowledgements

The original drafts of this wine making guide were prepared by Stan Gower. He has been assisted over a number of years by Spencer Field, George Wright, Neil Johannesen and Ken King, and in particular over recent years by Karen Coulston, who is a Life Member of the Guild, professional winemaker, and provides a laboratory testing service for wine makers.

Disclaimer....^

Wine making is an art as much as a science, and there are many different views on must topics. Also, different factors interact to complicate what is right or wrong. This guide has been prepared by the Eltham and District Wine Makers Guild primarily to help new wine makers get started, and the Guild and its members cannot accept any responsibility for any errors in this guide or misinterpretations by users. The ultimate teacher of wine making is experience, and that included making your own mistakes, and perhaps spoiling a batch of wine beyond fixing. That’s all in the game!!

Contributors Page

The EDWG Winemaking Guide was commenced by Stan Gower and is intended to be continuously improved by the contributions of its members and advisors.

Version..............Date...................Contributors..............Changes..............
0.1....1-Sep-2009......Stan Gower....First draft and photos 1.0 ...2-Jan-2010 ....Gary Campanella
Editing first draft, addition of Appendices A and B (White and Red wine making at a glance diagrams)
Editing for web publication
1.1 26-Jan-2010...Gary Campanella....Additions to Section 2 (Picking the Grapes)
1.2 15-Mar-2010 Gary Campanella Added link to Fining and Stabilisation article
Last Updated on Monday, 15 March 2010 11:31

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Sparkling Winemaking ... ^

Tuesday, 17 November 2009 11:35
I’ve come to regard anything that Bryce Rankin writes about winemaking is accurate, informative and practical. He is accessible to the interested amateur and this book is no exception. It is a text for makers of sparkling wines and those who have a general interest. It is a manual describing the production, from grapes to packaging. It is intended that a winemaker who has never made a bottle of sparkling could follow the process.

1. Liqueuring...^
In broad summary, once you have a base wine you put it into a bottle and inject with a sugar solution and start a secondary fermentation followed by crown-sealing the bottle. The conversion of sugar into alcohol and carbon dioxide results in a fizzy wine, made cloudy by dead yeast cells. You encourage the deposits to collect under the crown seal, and discharge the plug of sediment wine to waste. The resultant wine is then sugared to taste, sulphured to stop further fermentation and sealed once again. I guess it can get a bit more complicated than that, so read the book.

I made my first sparkling wine armed with just this set of knowledge and it tasted OK, so don’t get put off by the complexities that the professionals must master.

I will ignore most of the process and concentrate on the important information I was lacking when I made my first attempts: the liqueur and liqueuring. Two types of Liqueur are required: the one before secondary fermentation to produce CO2 in the bottle, and the liqueur to sweeten the final product after disgorgement.

The first addition can create problems. If too much sugar is added, resulting in a pressure in the bottle that is too high (danger of explosion by popping the crown seal or at disgorgement) or the opposite (not enough fizz). This book gives clear instructions about alternatives.

The fermentation liqueur (tirage liqueur) is made from cane sugar dissolved in wine a week or so prior to pouring into the bottle, giving time for the sucrose to invert (change to a sugar that yeasts can use as a food source). It should not ferment in storage because the sugar levels are too high. To make 1L of fermentation liqueur, add 0.5 kg cane sugar into 0.69L of wine base. Add some citric acid to assist in sugar inversion and adjust the pH to that of the base wine. For smaller volumes, change the proportions.

The amount of liqueur you add depends on the pressure you want in the bottle. A graph is given in the text outlining the CO2 (g/L) and pressures (kPa) for various temperatures (from –5C to 25C). You select the pressure you want for a given temperature and insert the required number of grams of sugar per litre of wine. For example, for a final pressure of 400kPa (4 atmospheres) at 20C then 7.25 g/L of carbon dioxide are required. You may decide to seek a pressure of 500-600kPa in recognition that some will be lost when you disgorge the sediment. For the moment I’ll stick with 400kPa.

1 g of sugar produces 0.49g of CO2. Therefore, for 7.25g of CO2 you need 7.25/0.49 = 14.8g of sugar per litre of wine. Because 1L of liqueur contains 500g of sugar (see above), the volume of liqueur required is 14.8/0.5 = 29.6ml of liqueur per litre of wine. ...

[That’s all theory. If I added the amount of sugar they do in commercial wineries I think I would blow up my house. After some experimenting now add eleven grams of sugar to each bottle and squirt in some re-hydrated yeast solution with a hypodermic syringe (with the needle removed). Then I crown seal the bottle. This seems to generate enough bubbles for an acceptable sparkle but not run the risk of explosions. I have found it useful to use a receptacle that holds exactly 11 g as a measure which I dip into the bag of sugar and then I don’t have to worry about scales at this messy time. I use granular sugar and toss it in using a funnel. I suppose it would be better to use a sugar solution, but I find the sugar dissolves pretty quickly anyway.] ..... ^

If you want to be more precise, the addition of the 29.6mL per 1L of wine will increase the volume of the blend and this can be allowed for. The formula for this is as follows:

V (wine) x V (liqueur) = Volume of liqueur

V(wine) – V (liqueur)

e.g. : 1,000/(1,000 – 29.6) = 30.5 litres of liqueur required where V (wine ) is the volume of wine and V (liqueur) is the calculated apparent volume.

When this is fermented to dryness the low pH and the presence of carbonic acid makes the wine taste very dry and further sugar is added to personal taste (from 2.5 to 80g/L). Less that 15g/l will still give a Brut sparkling.

Dissolving at a rate of 6.26g in 6.12mL of wine normally makes this final liqueur. However other additions are also possible: For example to make 1L of liqueur, mix together and stir till dissolved:

Sucrose 625g
Brandy 40mL
Matured Wine 570mL
Citric Acid 5g
To prevent microbial activity and oxidation in the bottle of sparkling wine, add SO2 to the liqueur to bring the level of SO2 in the final bottle of wine to 35mg/L. (You can work out the proportions required for your homework)....^

If you are still with me, the calculation of the final liqueur addition is as follows: To liqueur a dry (brut) wine to 1% sugar (or 10g/L) with a liqueur containing 625g/L of sucrose, the calculation is as follows. For a 750mL bottle of wine, the quantity of sucrose required = 10/1,000 x 750 = 7.5 gm/bottle.

If you are using liquor containing 625g/L sucrose, the required volume of liqueur containing 7.5g sucrose is: 1,000/625 x 7.5 = 12mL of liqueur for each 750mL bottle.

2. Disgorgement... ^
Part 1 exposed the depths to which an amateur winemaker must descend to achieve a clean bottle of sparkling wine. Part 2 are my notes on the expert account outlined in the Reference book.

The lees (dead yeast cells) that have accumulated in the neck of the bottle of sparkling wine that has undergone a secondary fermentation in the bottle needs to be removed and this process is called disgorgement. Disgorging is a skilful operation when carried out manually. Commercially, the neck of the bottle is usually snap-frozen and the ice plug is expelled, along with the lees.

The book also describes a technique used when bottles are at cellar temperature and no ice plug is used. When cork-sealed bottles are disgorged, the bottle is held at about 45 degrees below the horizontal with the gas bubble held in the shoulder of the bottle. Then, using a special pair of pliers, the clip is levered off the cork, holding the cork with the index finger of the other hand. The cork is then allowed to be slowly forced out of the bottle until explosion when the bottle is uprighted with a twisting motion to about 45 degrees above the horizontal, to position the gas bubble between the liquid in the bottle and the deposit. The deposit is blown out of the bottle by the pressure and the bottle is given a sharp tap with the plier that induces the wine to foam slightly to wash any remaining deposit out of the bottle.

So much for the theory and practice of experts! We now come to the pornographic processes of the amateur. ..^

I use crown seals for the secondary ferment (and for the final product – the cork and wire and metal dressing are aesthetic, but the crown seal is inexpensive and does the job). As described above, I tried the 45-degree tilt and moved the bubble to the shoulder just as I released the crown seal. And yes, I did manage to discharge the sediment so I have managed to achieve the required result, I suppose. But my mental image of the process described in the book has never matched my reality.

I do not have the experience to remove the crown seal with precision. Some flip off quickly, some slowly. The danger is in a hesitation in the movement, and believe me there is real reason for hesitation. Too quick a release results in massive foaming and you lose half a bottle of precious wine. Too slow and you waste the energy of the fizz to remove the sediment. If there is any hesitation in the movement while the cap comes off, the pressure in the bottle is released while the cap is only partially released. The plug of sediment and wine is expunged in foam caused by the bubble in the bottle and the pressure of CO2 in the wine; it hits the partially released cap and sprays with considerable force and magnitude back onto the disgorger and onto everything behind him. His clothes are saturated and for a considerable distance behind him, the surroundings are doused in wine.

After many tries, I find the only practical way to achieve disgorgement is to select a warm day in summer and to take my bottles into the garden. I find an area not too close to the house, but with a broad area of garden behind me, not too close to the neighbors. I strip to my underpants (I have a false sense of modesty) and proceed to flip off the crown seals with the utmost care and precision. I like to refer to these sessions as disgorgement, rather than disgorging because it lends an artistic flavour to an otherwise very ordinary experience.

In every disgorgement I have carried out, I end up with the garden covered in spray and myself in the shower before I can approach the task of re-dressing myself and topping up and re-sealing the bottles so that I can achieve the necessary clarity of sparkling wine. The neighbours have threatened to sell tickets for the event. Such is my passion for homemade wine. There can be no greater sacrifice. ...^

Postscript

I now buy a small amount of dry ice in an Esky and invert the bottles into it (for about 30 seconds). That’s enough to freeze the wine in the neck of the bottle. Then I flip off the crown seal and the plug of ice (with sediment) shoots into the neighbour’s yard. It’s less messy but you still need a shower at the end. Wear safety glasses and keep the bottle facing away from your face. If the plug gets stuck you can prod it with a screwdriver to help it fly out but don’t point it towards your face. The mobile plug of ice is dangerous. It would be safer to work with the bottle behind a Perspex screen but I haven’t used one.
Reference:
Armstrong. D Rankine B and Linton G. 1994 Sparkling Wines. The Technology of Their Production In Australia Winetitles Adelaide ACC 291991 BRN 173284 NMIT Library: ARM 663.2240994

Last Updated on Sunday, 03 January 2010 23:17 ...^ 

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