Vineyard & Winery Management Magazine
Feature Story
Barrel Care
Barrels can be one of the best places to store certain wines and one of the worst. This is mostly subject to what style of wine one wants to produce, how one cares for the full barrels, and how one stores barrels that are empty. The best rule of thumb for many is: A full barrel is a "happy" or "safe" barrel.
WHEN TO INSPECT YOUR BARRELS?
Every winemaker has his own way of taking care of his barrels. In essence, there is no right way to take care of a barrel, just many wrong ways. If one ignores the timely applications of some simple processes, the result may be a certain spoilage bacteria becoming established in the porous grain of the wood leading to a cumbersome battle for the future.
If we are timely and diligent in our barrel care, we save ourselves much time, work, and money keeping many oak barrels for up to a decade, or more if desired. Always visually inspect barrels when they are received from the cooperage and smell each barrel to familiarize yourself with its scent.
PREPARING NEW BARRELS
Most winemakers have several different ways to prepare their barrels for their first fill. This can range from no treatment (not recommended), to quick rinse, to head soaking, to full fill. Visually inspect and smell every barrel before filling so you know what your hard-earned juice/wine is about to go into and the flavors it will extract.
No treatment: Some winemakers will simply receive the barrel and fill it with juice or wine. In some cases the barrel will leak, so most winemakers generally do not recommend this. It's always better to find a leaky barrel with water. (Not recommended.)
Quick rinse: This can be acceptable in some cases if the barrel is allowed to actually soak up the water in order to swell beyond the leaking point. However, I still find risk with this process, unless you're using a form of pressure test to know that the barrel will not leak. (Not recommended.)
Head Swell: Some winemakers fill their barrels with about 10-15 gallons of water and allow them to sit on one head for 12-24 hours and then roll them over to allow the opposite head to have contact with the water. This, in my opinion, is still better than the above solutions because the time needed for the wood to swell is taken before placing juice or wine into the barrels.
Full fill: This involves either using cold or hot (120°F) water to completely fill a barrel about 24 to 48 hours prior to needing it. This time can be shortened if all looks well and leaks are not discovered. Remember not to extend the time, since the water can turn smelly and certain slimes/films may develop. Freshen the water or make a solution of citric acid water (pH to near 3.5 or lower) and SO2 (near 60-70 PPM). This solution will allow longer contact time with the wood if that is desired.
Depending on the cooperage used, I prefer to fill barrels with fresh water at 120°F, bung solid, and allow to cool overnight. Next, I empty the water and allow it to drain completely for one hour (bung hole facing upside down). The barrel is then righted, given another visual/smell check and filled.
FRESHLY EMPTIED BARRELS
Barrels that have been freshly emptied of wine are often overlooked for too long. An empty barrel will start to dry fairly rapidly so we must deal with it as soon as possible, even though we may be tired or distracted. As with any clean-up, it's much easier if one can get to the dirt before it dries.
Try to at least give the barrels a good solid rinse as soon after emptying as possible. It may be a reasonably high-pressure rinse to loosen and wash away the sediment from the barrel. Then start any other cleaning regimens, or if re-filling, one may be fully prepared to do so at this time.
If further cleaning is needed, this can also be a time to start a more serious high-pressure washing regimen, ozone or any other method to address a specific need.
Be sure to take the time to clean the bung area of the barrel both inside and out. The bung area can be a place for solids to dry and for bacteria to proliferate, if uncared for.
STORING OF EMPTY BARRELS
Most readers are probably scanning this article for answers just to this issue. Wide-ranging experiences have winemakers storing empty barrels in many different fashions. I prefer to rinse a freshly emptied barrel as described above, allow the barrel to drain overnight (bung downward) and then re-right the barrel with bung facing skyward.
Liquid sulfur dioxide: Fresh pure liquid sulfur dioxide can be the best choice, in my opinion, yet care must be taken when using this liquid gas. Please follow all MSDS and handling instructions. Another helpful common sense task is to only do this outdoors, upwind from the barrels, and away from others. I will typically meter 10 grams of pure liquid sulfur dioxide per 60 gallon (225 liter) barrel for the initial dose and then re-dose at five grams every month thereafter.
If I'm ever in doubt about what may be too much pure sulfur dioxide, I always lean toward more in the empty barrel because I haven't seen any literature suggesting negative effects with slightly higher use. (This is not to say that you should go higher than recommended or be excessive). Please be careful here.
Wicks and disks: This is another form of introducing sulfur dioxide into the barrel. Most sulfur wicks contain roughly 6 grams of actual sulfur dioxide in them and yield this upon burning. This is another great way to take care of your barrels when empty. Please remember to re-burn a wick/disc in the barrel every month.
Do your absolute best to store barrels, full or empty, in the best conditions possible. One should strive to store barrels full or empty at or as near 50°F, out of direct sunlight, avoiding excessive temperature swings and in a mold-free environment.
DIXIE CUPTM, STYROFOAMTM OR BUNG?
Some winemakers allow barrels to be stored unbunged after treatment with sulfur dioxide. These winemakers are few. Others use different methods of sealing the barrels to keep the risk of insects and small animals out of the barrels. The most popular methods are:
DixieTM cups: These fit nicely in most 50 mm bung whole openings and do a fine job at sealing the barrel just enough to keep the gas inside the barrel. They do tend to pop out as some actually like to store the empty barrel bung down while empty. (Not recommended.)
StyrofoamTM cups: These are similar to the DixieTM cup above, with essentially the same function. (Not recommended.)
Bungs: I prefer this seal to the barrel to best keep the gas in. It is also recommended to wrap these bungs in cling wrap to protect the bung silicone from the harsh sulfur dioxide environment. This is functional and the clear wrapping is a great way to identify empty wine barrels in your cellar. (Recommended.)
I have had little experience with glass bungs or other forms of barrel closures for this purpose. These may need further review in your own -cellar.
TYPES OF RINSE
Water: All types of rinse generally use water, which should be chlorine-free and have enough pressure to rinse the back and top of the vessel in question. This can be difficult with larger barrels such as puncheons.
High-pressure: Nice to have but not essential with overall good cellar practices. This will aid in tartrate removal and it has much more logical mechanical pressure removal than just typical water pressure in a -winery.
Ozone: More and more popular, but this process must be used with caution and in well-ventilated areas. With best cellar practices these machines should not be needed, but they are a great tool to fight back when bad spoilage bacteria become troublesome.
Many thanks to enologists Jacques Boissenot and Jacques Rech, as well as to Mark Heinemann and all the Demptos Cooperage team for their help. (Full disclosure: The author represents Demptos on the East Coast.)
Tom Payette consults with established -wineries to improve their products and systems and assists in new winery start-ups.