How Barrels Work and How to Care for Them

First published on Distillique's website 2015 GM Bosman

Oak barrels are more than just expensive liquid-tight containers that give oak flavor to spirits and wines. They soak-up and breathe, flex, filter oxygen out of the air, aid wine and spirit maturation and allows spirits to develop unique character.

They flavor and color our spirits and allow the most volatile (and mostly unwanted) components of our distillates to "disappear".

A brand new (first fill) french oak wine barrel easily costs more than R16 000.

Luckily, these are unsuited for aging distilled spirits. As barrels get used (first fill, second fill, third fill etc) they get infused with the wine, sherry, port or eventually brandy, that matures in them. Sherry/Port oak barrels are most suited to mature and age spirits.

How Oak Barrels work:

Evaporation
The Oak wood in a Distillique barrels has been specially selected for its a fine, porous micro-structure which, in the tree, helps supply the nutrients that allow it to grow. This micro-porosity capillaries, like blotting paper, suck the liquid components of spirits (mainly water and ethanol) through the barrel wall and out to the barrel surface where they evaporate. This evaporation is enough to force a vacuum within a stoppered, tight barrel. French Oak is generally more porous than American Oak.

Micro-oxygenation
As the porosity of oak runs "both ways", the vacuum inside allows outside air (20% Oxygen) to be sucked into the barrel until an equilibrium is reached between the rate of evaporative loss and the rate of incoming air. At equilibrium, the barrel vacuum stabilizes at about -0.12 atmosphere in a "tight" barrel. However, differences between individual barrels causes barrels to behave differently and each barrel finds its' own equilibrium.

Flavoring
As the air enters the barrel through the force of the vacuum, the "oak flavor" (mainly phenolics) is drawn from the oak into the alcohol with the air. These infused compounds, also need extended maturation time to develop character and complexity.

Maturation
By law, brandy should be aged at least 3 years in oak barrels not larger than 360 liters, before it may be called brandy. This period is considered a minimum to allow the characteristic flavor and coloring of brandy to develop. Small quantities of caramel may be added to enhance the coloring without affecting the taste. However, smaller barrels age (infuse) spirits much faster than larger barrels. You may find that on small barrels a few weeks are perhaps more than enough. If your spirits have "over-wooded", just add neutral spirits to reduce the woodiness.

Solera Brandy
A solera is a series of barrels (called butts in the solera), each holding a slightly older spirit than the previous one beside it. When brandy is racked (drawn off) from the last butt (no more than a third of the volume is removed) it is replenished with brandy drawn from the previous butt in line all the way down the solera line to the first butt, where newly distilled brandy is added.

This system of racking the brandy through a series of butts, blends together a variety of vintages (some soleras have over 30 stages) and results in a speeding up of the maturation process, and greater consistency in the character of the brandy over time.

Home Distiller's Soleras
A series of 4,5 liter, 9 liter or 25 liter barrels are quite suitable for the home distiller to age brandy and develop your own solera for consistency. Aging in these smaller barrels happens faster as the alcohol gets exposed to more oak interaction than in larger barrels.

For the home distiller, a solera can consists of only one barrel, being topped up regularly with "fresh" brandy, or may consists of as many butts as you have space for. As a rule of thumb, the more butts in a solera, the better the consistency, aging and character development of the brandy.

Distillique Barrels
Distillique barrels are all handmade by master craftsmen in the age old tradition of cooperages. The oak is selected from french oak barrels used for red wine, sherry or port production and imparts a pleasant, lush, slightly sweet and fruity note to the character of home distilled brandy.
Our barrels range from 1.6 lt to 50 lt and barrels up to 360 lt are available on order for brandy or whisky maturation..

How to care for your barrels
As the proud owner of a hand made oak barrel, like all things beautiful, your barrel needs a little care and attention from time to time.

By following the next few guidelines, you barrel will become a valued family heirloom.

1. The oak from which your barrel is made, may have shrunk slightly while being empty and transported to you. Fill it with COLD WATER and allow it to stand for at least 48 hours before use. If, after the 48 hours it still leaks, keep it filled with water until the water stops leaking (sometimes up to a week). It is normal that a barrel leaks when new or when it has dried out.

2. After this first soak, vigorously shake the barrel with clean water and empty it through the filling hole a few times. Some "gluey white stuff" will be seen in the rinsing water. This is some dough (flour and water) that is used (the traditional way) to seal the barrel staves against the head. On especially small barrels, this dough is rather difficult to remove from the barrel during manufacturing and the excess might cloud your spirits if not rinsed out.

3. Always rinse vigorously with COLD WATER before filling with any type of wine or spirits.

4. Try keeping the barrel as full as possible to allow all wood internally to be "wetted" by the wine or spirits.

5. When using spirits, do not age the spirits with the tap installed on the barrel. Remove the tap for aging and plug with a cork. Turn a full barrel on its side when inserting the tap for decanting from the barrel. Then remove the tap again for proper aging.

6. NEVER leave a barrel almost empty. Fill up with cold water if you intend not using it for a while. The barrel should not be allowed to dry out after it has been filled.

7. Rinse the outside of the barrel (but NEVER immerse the barrel) with COLD WATER after completely emptying the barrel for a next fill.

8. Keep you barrel in a cool place out of sunlight.

9. You may store sherry, brandy, sweet wine, whiskey or any other spirits in you barrel for any length of time. Fruit juices and wine may be served from the barrel, but not left standing in the barrel for longer than 24 hours as it will loose its flavor.

10. The barrel should be rinsed with COLD WATER before and after each use.

NEVER use hot water with your barrel as the wood will expand unevenly and too much and damage your barrel permanently.