Wine is an alcoholic beverage resulting from the fermentation of grapes or grape juice. This article provides a brief synopsis of the wine making process. Wikibooks logo Wikibooks, previously called Wikimedia Free Textbook Project and Wikimedia-Textbooks, is a sister project to Wikipedia and is part of the Wikimedia foundation, begun on July 10, 2003. ... Wine is an alcoholic beverage made by fermenting grapes or grape juice. ...

Basic steps

The following is a list of the basic steps involved in making wine:

1. Grow grapes until ripe. Ripeness can be judged using the Brix scale, or by waiting for the grape's moment of "physiological ripeness" by taking into account the ripeness of the seeds and skin of the grapes, based on color or other attributes.
2. Remove stems and crush to release the must. If using carbonic maceration, crushing is unnecessary.
3. For white wines, press the juice off the skins. The juice that comes out from the pressure of the grapes alone is called "free-run" juice, and is generally saved and fermented separately. Some appellations and regions regulate how much juice may be pressed from a given mass of grapes.
4. Optionally, allow the juice to rest under refrigeration, to prevent fermentation. This period of maceration helps extract the maximum quantity of compounds from the skins.
5. Induce fermentation by introducing a yeast culture. Never allow wild yeast to ferment the wine naturally as this can ruin the fermentation.
6. Keep the wine in a cool ventilated location, in a food-grade container that has a way for the CO₂ produced by the yeast to escape (which is one reason for the ventilation). Home winemakers often use carboys; commercial fermentation of larger amounts of juice is done in stainless steel containers.
7. While fermentation is active in a red wine, the seeds and skins will rise to the top of the fermenting vessel. This "cap" needs to be kept wet with fermenting juice for maximum extraction. To achieve this, punch down the cap at regular intervals.
8. The Specific Gravity of the fermenting must is periodically measured to determine when fermentation is complete.
9. Separate the juice from the skins (if this is a red wine), seeds, and fruit pulp. This may be done at various points, usually at the end of tank fermentation.
10. Optionally, either during alcoholic fermentation or while in storage, induce malolactic fermentation. Many reds and some whites undergo this process to convert sharper malic acid to softer lactic acid.
11. When tank fermentation is complete, "rack" (draw off) the wine from the settled yeast cells and sediment which is called the lees. Or, leave the wine with its lees to age sur lie. Most winemakers add sulfur dioxide to prevent both oxidation and any further fermentation.
12. Most solids suspended in the wine will settle out on their own, given a little time. However, this could take months, and does not always result in a crystal-clear wine. Commercial wines sometimes use fining agents such as bentonite (a kind of clay) or egg whites to remove these suspended solids. Filtration is also used to remove solids from wine and to remove all yeast and some bacteria cells.
13. Wine is transferred to storage tanks (or for some wines, oak barrels, to allow the oak to impart additional flavors to the wine). Store the wine for anywhere from three months to several years.
14. Optional: blend wines from different areas, years, and grape types. If producing a wine designed to meet a certain appellation, check local regulations for what is allowed.
15. Bottle the ready wine. Continue its ageing in the bottle if appropriate.

If you wish to make a country wine from ingredients other than grapes, the procedure is similar. Usually refined sugar or another sweetener is necessary; add it before fermentation begins. Species Vitis acerifolia Vitis aestivalis Vitis amurensis Vitis arizonica Vitis x bourquina Vitis californica Vitis x champinii Vitis cinerea Vitis x doaniana Vitis girdiana Vitis labrusca Vitis x labruscana Vitis monticola Vitis mustangensis Vitis x novae-angliae Vitis palmata Vitis riparia Vitis rotundifolia Vitis rupestris Vitis shuttleworthii Vitis tiliifolia Vitis... Degrees Brix (symbol °Bx) is a measurement of the ratio of dissolved solids to water in a liquid. ... Must is the juice of freshly pressed grapes, prior to fermentation into wine. ... In winemaking, the process often used in Beaujolais, in which whole grapes are fermented without crushing. ... An appellation in its broadest sense is a name or designation. ... A region can be either: an administrative subdivision of a country a sometimes vaguely-defined geographical area of a country or continent It is important to realize that regions are found in the minds of humans and so regions can be of any size and that each region is unique... In its strictest sense, fermentation (formerly called zymnosis) is the anaerobic metabolic breakdown of a nutrient molecule, such as glucose, without net oxidation. ... Maceration is a process which takes place during the fermentation of wine. ... Yeasts constitute a group of single-celled (unicellular) fungi, a few species of which are commonly used to leaven bread , ferment alcoholic beverages, and even drive experimental fuel cells. ... Wine is an alcoholic beverage made by fermenting grapes or grape juice. ... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ... A carboy is a glass vessel used in fermenting wine, mead and sometimes beer. ... The pinnacle of New Yorks Chrysler Building is clad with stainless steel In metallurgy, stainless steel (inox) is defined as a ferrous alloy with a minimum of 10. ... Malolactic fermentation is a process of fermentation where tart malic acid is converted to softer-tasting lactic acid. ... Malic acid is a tart-tasting organic acid that plays a role in many sour or tart foods. ... Lactic acid (α-hydroxypropanoic acid, AHA) is a chemical compound that plays a role in several biochemical processes. ... Sulfur dioxide (or Sulphur dioxide) has the chemical formula SO2. ... Bentonite - USGS Bentonite is an absorbent aluminium phyllosilicate generally impure clay consisting mostly of montmorillonite, (Na,Ca)0. ... Quaternary clay in Estonia. ... Albumen redirects here. ... Whiskey barrels at the Jack Daniels distillery Barrels for aging wine in Napa Valley An aging barrel is a barrel used to age wine or distilled spirits such as whiskey, brandy, or rum. ... Country wines are fermented alcoholic beverages made from a variety of ingredients other than grapes (the base of ordinary wine) and having a variety of flavors. ... Refining is the process of purification of a substance, usually used of a natural resource that is almost in a usable form, but which is more useful in its pure form. ... Magnified view of refined sugar crystals. ...

Winemaking at home

Until the early 20th century, most wine drinkers produced their own wines at home out of necessity, as the average bottle of commercial wine could cost up to a month's wages for a farmer or factory hand. As can be imagined, the quality of these homemade wines was very uneven and the alcohol content sometimes greater than would be expected.

In the last thirty years, however, the task of home winemaking has become easier and results much more predictable. Nearly every good-sized city in North America and Western Europe has at least one shop catering to home brewers and winemakers. Kits make it possible to produce decent table wine at a fraction of the cost of even the cheapest wine in the liquor store.

Making wine at home isn't necessarily easy. There's a lot of work involved, especially in cleaning and sanitizing, but the sense of accomplishment the winemaker can get from producing 30 bottles of extremely drinkable white wine for less than $2.00 a bottle cannot be understated. Although one could theoretically make wine with nothing more than grapes, a big barrel, and some young maidens to stomp the grapes, most winemakers find the following equipment necessary to produce decent wine on a predictable basis:

• a 30-liter or larger food-grade plastic container (similar in shape to a garbage can) with a non-airtight lid and a mark at the 23-liter point
• a 23-liter glass or food-grade plastic carboy
• an airlock and bung (rubber stopper with a hole in it) for the carboy
• a hydrometer to check the specific gravity (s.g.) of the wine
• a long, narrow tube or jar to hold the wine while you're checking its s.g. (generally the tube the hydrometer comes in works fine)
• a dairy thermometer
• a long piece (at least 1.5m or five feet) of food-grade plastic tubing
• a long spoon that can fit into the neck of the carboy and reach the bottom
• a wine thief to remove the developing wine from the carboy without having to tip it

It is essential that any plastic items that are in contact with the wine be made of food-grade plastic. Regular plastic can and will leach polymers into the wine, which will give it an odd plasticky taste. A carboy is a glass vessel used in fermenting wine, mead and sometimes beer. ... An airlock is a device which permits the passage of objects, people, etc between a pressure vessel and its surrounding space while minimising the change of pressure in the vessel. ... A hydrometer is an instrument used for determining the specific gravity of liquids. ... A wine thief is a glass or food-grade plastic pipette used in the process of wine making. ...

All of these items will last basically forever, and most wine stores stock a reasonably priced starting kit. If you decide to brew beer as well, you can use most of this equipment, but you'll need a separate 30-liter plastic container (as the taste of the wine will remain in the plastic) and you should make sure your carboy is glass. A mug of lager beer, showing the golden colour of the beer and the foamy head floating on top. ...

For every batch, you'll also need the following:

• something to ferment. Generally that means grape juice, but wine has been made from almost all fruits, especially crabapples and elderberries. Winemaking stores sell kits containing between eight to thirteen litres of concentrated grape juice of various varieties such as Riesling, Merlot, and Chardonnay. If you're not into a specific variety, you can use unpasteurized grape juice, but it tends to be a bit more expensive and your results might not be as predictable.
• good quality water. Generally in the city or on the farm this means filtered water. Heavily chlorinated water (common in the spring) can skunk your wine.
• wine yeast. The type of yeast you use will affect the flavour of your finished wine. Bread yeast can be used in a pinch (say, if you're making wine behind enemy lines during a war), but generally if you're not in dire circumstances you want to use a wine yeast tailored for the type of grape or other fruit you're using.
• something to settle the wine. You can use sterilized bentonite, isinglass, or (again, in a pinch) egg whites. The first two are readily available at any winemaking store.
• something to stop fermentation. You can use a little pure ascorbic acid (Vitamin C, but don't use vitamin pills containing sugar or flavouring), or you can buy a packet of potassium sorbate at the wine store.
• bottles and corks. You can reuse bottles, and unless you're making champagne it doesn't really matter what type of wine bottle you use as long as you get it clean. The best way to do this is to remove any garbage in the bottles, soak them in water with strong detergent to remove the labels and the glue, wash them again in new water and detergent, rinse well, and sanitize. New bottles are also available at a reasonable price and can be reused indefinitely. You'll need 30 bottles for a standard 23 litre recipe. Both natural and synthetic corks work well (although the natural is cheaper); you'll need longer corks if you plan to keep the wine for longer than six months.

• sodium metabisulfite for sanitizing. Warning: Do NOT use this under any circumstance whatsoever if you or anybody in your family has asthma. Use iodophor or bleach instead. Sodium metabisulfite is the most convenient form of sanitizing, and sanitize you must if you want your wine to turn out as wine and not as vinegar. If you must use iodophor, follow the instructions on the label and rinse well. If you use bleach, soak your items for 10 minutes in a 5% bleach concentrate, then rinse at least six times thoroughly. Sodium metabisulfite is perfectly safe for the average person, but it can cause a serious reaction in asthmatics, so heed the warning.
• detergent. Dish detergent is probably not strong enough. Wine stores sell strong, unscented detergents that do a better job at removing labels, old smells, etc.

The process of actually making the wine is simple but somewhat tedious. Kit wines must be prepared according to the manufacturer's instructions. Otherwise, the following is a good rule:

• make sure the area in which you're making your wine is at a stable temperature below 23C or 75F. At higher temperatures, the chances of your wine turning into vinegar are increased.
• clean and sanitize everything just before it touches the wine. That includes any funnels, cups, bowls, and other items. If you have to use them on two consecutive days, clean and sanitize before every use. A good yeast will outgrow the odd bacterium that gets in, but the sloppier you are the more likely something like acetobacter is going to get in and turn your wine to vinegar.
• pour your juice into the large plastic container. If you're using a concentrate, top up with filtered water to 23 litres. You want the finished product to be between 65 and 75 F or 18 to 23 C. Test with your sanitized dairy thermometer when you're up to 20 litres, and add hot or cold juice or water at the end to adjust the temperature.
• stir like mad.
• add yeast.
• check your specific gravity by putting the sanitized hydrometer right in the container. It should show a s.g. of about 1.010 or greater. If it's less, you probably want to add a bit of sugar syrup and stir, then check again. Remove the hydrometer.
• put the lid on. If you live in an area with lots of little flies, cover the container with a big plastic sheet and tie it closed with some string or twine around the middle of the container.
• in a day or two, your must should be bubbling away. Soon after that the yeast will drop to the bottom of the container and you won't see it working, but it'll still be fermenting.
• after a week, clean and sanitize the carboy, the bung, the airlock, and the plastic tubing. Siphon the must into the carboy. Leave out as much of the sedimentation on the very bottom as you can. Attach the bung and the airlock, making sure to fill the airlock halfway with water.
• cover the carboy with a dark, clean, thin sheet if you're doing this in an area where light can get to it.
• wait ten days and check the specific gravity. The best way to do this is to use the wine thief to transfer a little wine from the carboy to the measuring tube (the one the hydrometer came in), then use the hydrometer to check the specific gravity. If you started out at 1.010, you're looking for a s.g. of about 0.998 or lower. Check this once a day until the s.g. is the same on two separate days.
• remove the bung and airlock and add whatever you're using to stop fermentation and to encourage settling. Stir for five minutes straight. Make sure to stir up all the sedimentation on the bottom. Replace the bung and airlock.
• fourteen days later, clean and sanitize your bottles and your tubing and siphon the wine into the bottles and cork. You can buy a corking machine, or you can rent or borrow one from your friendly wine store - many stores lend them free of charge to their customers. Most corks are sold pre-sanitized, but you can soak them in a sulfite solution if you can't buy them already prepared.
• let the bottles sit upright for three days, then let them sit on their side for at least a month. If you've made red wine, you should leave it for a year. If you do hold wine for over six months, you may wish to add a bit of sulfite to prevent discolouration, unless of course someone in the house has asthma.

It's a bit time-consuming but there's nothing more satisfying than enjoying a delicious glass of wine that you made in your own kitchen. Acetobacter is a genus of acetic acid bacteria characterized by the ability to convert alcohol (ethanol) to acetic acid in the presence of air. ...

See also

• Wine
• Noble rot
• Sweetness of wine
• By-product Grape seed oil

Wine is an alcoholic beverage made by fermenting grapes or grape juice. ... Noble rot (French: La Pourriture Noble) is the benevolent form of a grey fungus, Botrytis cinerea, affecting wine grapes. ... The sweetness of a wine is defined by the level of residual sugar or RS (residual spunk) in the final liquid after the fermentation has ceased. ... Grape seed oil (also grapeseed oil) is a vegetable oil pressed from the seeds of various varieties of Vitis vinifera grapes, an abundant by-product of wine making. ...

Related links

• The Winemaking Homepage - Jack Keller
• The Home Winery
• Winetopix.com - Information for Wine Lovers