Wine must be protected from oxygen, so bulk wine is always stored in full, sealed, containers. Small batches of red wine are usually fermented in open containers. New red wines are then stored in closed containers after pressing. White and blush wines are best fermented in closed containers, and most commercial wineries ferment their red wines in closed tanks. Large volumes of carbon dioxide gas are produced during fermentation, so wine storage containers must be sealed with fermentation locks until all the sugar is gone. Most fermentation locks contain a water trap of some sort. The trap lets the carbon dioxide gas escape but prevents air from entering the container.

Glass

Five-gallon water bottles are readily available, and these are the containers most often used by beginning home winemakers. Water bottles have advantages and disadvantages. Glass can be cleaned easily, and it can be completely sterilized. Glass is transparent, and the progress of fermentation can be easily monitored visually. On the other hand, glass containers are heavy, and some winemakers find moving full carboys difficult. Glass is slick and fragile, and handling heavy glass bottles with wet hands can be dangerous. Five-gallon water bottles are a bit too small for long term wine storage because of the oxidation problem. However, a few water bottles are handy for storing leftovers for a few months. Another negative factor is the high cost of glass. The price of a new glass water bottle is about $16.00 (more than $3.00 per gallon).

Polyethylene

Polyethylene is a recognized "food grade" material, and polyethylene drums are widely used for shipping and storing liquid food products. Wine can be safely stored for extended periods in heavy walled containers made of dense polyethylene. Polyethylene is light, strong and inexpensive, and several firms now produce polyethylene tanks specifically for use as wine storage containers. New and used poly drums are available in 20, 30, 40 and 55 gallon sizes, and they make excellent wine storage containers. Wine storage containers made of polyethylene also have advantages and disadvantages. They are light weight, so polyethylene drums can be handled and stored easily. Best of all, they are inexpensive. Unfortunately, polyethylene has a porous micro-structure, and the small pores make this material difficult to clean completely. Used polyethylene drums can retain odors for long times, and the odors can contaminate wine. Consequently, secondhand drums must be selected with care. New poly drums sell for about $1.00 per gallon, and good used drums (used for food products) can often be purchased for a few dollars.

Stainless steel

Most winemakers agree that stainless steel is the best material for fabricating large wine storage tanks. Polished, stainless steel surfaces are easily cleaned, and properly designed stainless tanks are inert and tight. Although stainless steel containers are expensive, they give many years of trouble free service. Home winemakers often use surplus stainless beer kegs for wine storage containers. The deposit for a 15-gallon beer keg is about $15, and finding a first class wine container for less than a dollar per gallon is difficult.

Oak

Standard wine barrels come in sizes of 200 liters (52 gals) and 225 liters (59 gals). Oak barrels impart a vanillin flavor to the wine, and this oak character is desirable in most red and some white wines. After a barrel is four or five years old, it no longer produces the desirable flavors, so wineries must replace their barrels from time to time. A few wineries replace all of their barrels each crush season, but most wineries replace 20 to 30 percent of their barrels each year.

Barrels full of wine require little extra attention. However, empty barrels are difficult to maintain, and they require a great deal of attention. When a new barrel is first filled, almost four gallons of wine soak into the wood. When a used barrel is stored empty, the wine in the wood starts turning into vinegar in just a few days. Sterilizing oak barrels is practically impossible, so barrels infected with vinegar bacteria must be discarded. Commercial winemakers avoid this problem by not emptying their barrels until new wine is available. The barrels are washed with clean water as they are emptied and then immediately refilled with new wine.

Oak barrels have several other disadvantages. Barrels are heavy and difficult to handle. Empty barrels weigh almost 100 pounds, and full barrels weigh about 600 pounds. Empty barrels can be moved by hand without much difficulty, but moving full barrels more than a short distance by hand is seldom feasible. Wineries place full barrels on pallets, and the pallets and barrels are then moved with a fork lift. Oak barrels are often attacked by wood-borers unless treated with a special preservative. Eventually, any barrel will develop a leak.

New French oak barrels cost about $600, and new American oak barrels cost about $200. Clean, sound, used, barrels can often be purchased for $25 to $75 from commercial wineries

Summary

Most home winemakers use glass water bottles, polyethylene drums, stainless steel beer kegs or oak barrels for bulk wine storage. Because of the difficulties outlined above, novice winemakers are advised to avoid oak barrels until they gain some winemaking experience. Polyethylene drums are light weight, easily handled and inexpensive. Stainless steel beer kegs are inexpensive and last for many years. Poly drums and beer kegs are usually the most practical bulk wine storage containers for home winemakers. All wine storage containers must be kept full, so winemakers collect a variety of containers. Several one-gallon glass jugs and a few five-gallon carboys are always handy for storing leftover wines.