Storing Wine Ingredients

Make wine at home for a few years and you will probably accumulate a lot of stuff. Pieces of equipment join the collection as the needs and resources come up. Consumable supplies are not always packaged for single-use applications and the leftovers hang around. Maintenance and cleaning supplies are often cheaper in larger packages, so while you are it at, you might as well get the economy size. All of it goes in a corner of the garage, in the basement, to a convenient outbuilding, or wherever else you can find room to stash it while not actively making wine. For this column, we are addressing just those supplies that serve in a direct wine-addition capacity. We have our imaginary winemaker’s cupboard and we are going to take a look inside. What belongs in there? How should it be stored? How long can you keep it and still get reliable results the next time you use it to make wine?

Rather than relying on just accumulating things at random, we will look at the deliberate collection of things likely to be useful. Considerations include whether to store something at all or to acquire it only on an as-needed basis. Of course, any such consideration starts with the nature of the product itself — what it is. From there, we can look at proper storage conditions, a reasonable shelf life, and tips for maximizing value over time. Regardless o

f the material or its purpose, some basic rules of thumb will help in almost every case. First, make sure the product is clearly labeled. If you transfer it to a new container from the one it came in, transfer the label information as well. Second, if you do use a different container, make sure it is compatible with the material to be stored (more on that later). Finally, write the date on it. Not all winemaking products include expiration dates on the label and it does not do you much good to know the shelf life of a product if you don’t know when you brought it home!

If possible, choose your cupboard in a mild-climate location to store the various winery supplies. Cool, dry, and dark works for almost everything. Conversely, hot storage conditions will spoil many products in a short time. Oxygen is often the enemy; keep containers tightly closed and, for some products, minimize headspace. Direct sunlight or fluorescent light (both rich in ultraviolet wavelengths) will also contribute to oxidation of many products. Moisture may react and allow chemical transformation or microbial spoilage.

To consider the wine addition products, I will divide the sequence into three broad periods in the life of homemade wine: At the crush and fermentation, during the cellaring period, and when you bottle. First among the crush-time products is your choice of sulfite addition. When making wine from fresh grapes, a sulfite addition at the crusher is often the first chemical intervention in the process. You want your sulfite to be potent, effective, and of known concentration. Commonly available sulfite forms include sodium metabisulfite powder, potassium metabisulfite powder, Campden tablets, and effervescent sulfite tablets. Although they differ in molecular weight (MW), potassium metabisulfite (222 Daltons or Da) and sodium metabisulfite (190 Da) behave very similarly in use and storage. The solid material is fairly stable, although it loses strength over a period of months. A good rule of thumb is to replace sulfite solid materials after no more than about two years if stored under cool, dry conditions. If you have a desiccator, store dry powders in it. Similarly effective is inserting into each container or bag a new (or reconditioned) desiccant pack like the little silica gel packets that come with new electronic equipment. Keep powders or tablets in their original plastic containers or bags or transfer to a container that is polyethylene (PE), polypropylene (PP) or polyethylene terephthalate (PET). All three of these plastics are available as food-safe containers and I will refer to them as “plastic containers” for the remainder of this column. Tupperware brand containers, for instance, are mostly made of PP or PE. When solutions are prepared for use, higher concentrations last longer. A 10% solution is reasonably stable for a year or so but I would replace a three-percent solution after six months. Tightly closed glass or plastic bottles work well for these solutions.

The next addition that might occur could be an acid. Tartaric acid, citric acid, and acid blend are all solid materials with good shelf stability. It is worthwhile to keep tartaric acid on hand for acidification trials and possible addition to low-acid musts, but it is rather expensive so do not buy more than you anticipate needing. Citric acid is useful to neutralize porous materials such as plastic or wood that have been washed with alkaline cleaners like soda ash or sodium percarbonate. Acid blend is used mostly by makers of wine from fruit other than grapes; only buy it if you have a recipe that requires it. Store acids in the original plastic bag or use plastic containers. Glass jars are also very inert, but metal lids may corrode when used on acid containers. Stick with plastic lids for acid storage.

After acids, you may find yourself adding enzymes and yeast. As these are biological agents, the storage period is likely to be much shorter than sulfites or acids. As originally packaged in vacuum-sealed “brick” packs, active dry wine yeast is considered to have a shelf life of four years from the date of manufacture. That said, however, it should be noted that the producers expect the dry yeast to be dying at a rate of about 15% per year. The specifications for viability are written such that four years of such loss will still allow meeting minimum requirements. As a practical matter, any small packages of yeast should be viewed as having a much shorter shelf life. Pay attention to expiration dates on the yeast packages and use them before they expire. Enzymes are biological, but not alive. For them, you can probably extend to a second harvest after initial purchase, but not much further. Store in sealed plastic containers with minimal airspace. Because of their short lives, it is not usually practical to keep yeast or enzymes on hand.

Some winemakers add oak powder or oak chips to primary fermentation to help stabilize color and improve eventual mouthfeel. There are plant-derived enological tannins that are applied in a similar manner. All of these products are very, very stable. The only significant risk is loss of native aromas due to exposure to heat and air. Kept dry, cool, and sealed in a bag or plastic container, oak products and tannins should stay in good shape for several years. The same conditions apply to oak products used later in wine production, like balls, cubes, sticks, or staves. Because these products are so stable, do not hesitate to buy the ones you like in economic quantities.

In most fresh-grape fermentations you will be adding nutrients. The simple mineral nutrient diammonium phosphate (DAP) is very stable. It is distributed industrially in 50-pound (23 kg) paper sacks that include a polyethylene bag liner. In that format, the producers advise a 24-month shelf life under normal storage conditions. Under good storage conditions in the winemaker’s cupboard it should last at least that long and likely longer. If it remains loose, free flowing, and white in color go ahead and use it. Because of its good stability, keep some on hand. If a primary fermentation suddenly exhibits a rotten-egg hydrogen sulfide stink, adding DAP at one gram per gallon will quickly clear it up. More complex yeast nutrients like Fermaid K, Go-Ferm, or Superfood contain inactivated yeasts, minerals, and B vitamins along with DAP. Due to their complex blends, these nutrients may have a shorter shelf life than the mineral DAP. Lumps may form if exposed to humidity. If that happens, or if an unpleasant aroma develops, discard the nutrient. Otherwise, if it stays free flowing with a light yeasty smell and pale tan color, you may be able to hold onto it for two to three years. Not as essential to keep on hand as DAP, but it doesn’t hurt to have a little bit hanging around.

After all these primary fermentation additions, most red wines and some whites move on to malolactic (ML) fermentation. That requires inoculation with ML bacteria culture. These cultures are usually freeze-dried and come in a package with an expiration date on it. The lifetime is about 30 months in the freezer or 18 months in the refrigerator. Once opened, the entire package should be used. The use of ML bacteria can usually be planned and there is not a need to keep any on hand.

The next major phase in production of your wine can be rolled together in the term “cellaring.” Sulfite additions remain paramount, of course, and the storage conditions cited above continue. You may have applications in the cellar for inert gases, either in commercial cylinders or little aerosol cans like the product “Private Preserve.” As the name “inert gas” suggests, these products are non-reactive. If the container is not damaged, the product could probably outlast the winemaker — no matter how long you have it, it won’t go bad.

You may be inclined to use a fining agent during wine cellaring. Among these products, stability varies a great deal. Bentonite is a natural clay mineral and PVPP (polyvinylpoly-pyrrolidone, Polyclar) is a synthetic polymer — a plastic-like material. Both are extremely stable and will likely remain usable for several years. Sparkolloid is a dry mixture of silicate minerals and natural alginates derived from seaweed. Its producer, Scott Laboratories, reports a 4-year shelf life under good storage conditions. For all of these products, as long as the material remains loose and free flowing and has no off-odors, it is probably safe to apply to your wine.
Powders that are potentially much less stable include isinglass and gelatin. Both derived from animal sources (fish for isinglass and pigs for gelatin), these materials are highly absorptive. While that is beneficial in their use, it means any exposure to humidity or odors may cause unwanted absorption. While producers may claim that gelatin powder can last as much as five years in perfect storage, I do not trust these products beyond one or two years at the most. They are also available as liquid preparations with a much shorter shelf life. If you purchase one of these protein-based fining agents as a liquid, use it in the same wine season and discard the leftovers. Opened containers should be used up right away, so purchase only for specific applications.
In addition to the general fining agents, there are specialized treatment products that may also be applied in the cellar. One of these is copper sulfate solution for sulfide removal. This is a simple mineral salt dissolved in distilled water. Kept in a sealed glass or plastic bottle, it will keep indefinitely. Since you never know when it might be called for, it is worthwhile keeping some on hand. Yeast hulls or inactivated yeast also may be used in wine treatment. Either plain or formulated into specialty products such as Reduless or Noblesse from Lallemand, they have moderate shelf lives. Unopened packages may be good for as much as three years, but after opening use in one year or less. Considering the shelf life, it may be best to wait until needed to buy these materials.

The final phase for cupboard consideration is bottling additions. Oak treatments have been described earlier. If you wish to sweeten wine at bottling, you may want to use sugar or grape concentrate. Dry sugar is stable for several years and you have it in your kitchen already! Grape concentrate in cans is stable for a year or more, but one year would be about maximum for concentrate in plastic bags or jugs. If you sweeten, you will also want to add potassium sorbate to prevent refermentation. Potassium sorbate powder should be kept in the dark as it is light-sensitive. Properly stored, it should be stable for a year or more. Gum Arabic is sometimes added to improve stability against tartrate precipitation. As a powder, it is stable for several years. For home winemakers, however, gum Arabic is usually sold as a liquid solution. This material should be viewed as stable for a year or less and should be purchased for the specific bottling season.

So there you have it. Buy some materials fresh upon the occasion for use. Keep a few things on hand for repeated application. Inspect stored materials for clumping, off-colors, or unpleasant aromas before using in your wine. And keep your winemaker’s cupboard cool, dark, and dry.