Oak used in Cooperages

[scout]

I thought I would put this up for anyone who wanted to know a little bit about my craft. It may prove useful and it will at least be information many may not have at their disposal.

Oak Wood Composition*
Significant variation occurs in the composition of oak heartwood. There are many factors that contribute to this variation. These include: differences within a tree, age of the tree, rate of growth, soil and climate of the region, and more importantly, the genetic differences between various species. Variation Within a Tree Within a given tree, variation in the heartwood composition can be considerable. For example, heartwood close to the sapwood is richer in tannin than the heartwood close to the pith. Higher tannin levels are found in the base of the tree than near the crown. The tannin content increases as the tree gets older. Soil, climate, and other environmental conditions also affect growth and composition of heartwood. Although significant differences in composition can be found within a tree, as well as among the trees, these differences are minimized during the process of barrel making. A 50-gallon barrel is made out of 30 plus staves. The staves in a given barrel may come from different segments of the same tree or from several trees grown in a given area. Variation Due to Rate of Growth The rate of growth also affects the heartwood composition. A slower rate of growth is characterized by a greater proportion of spring wood and a smaller proportion of summer wood. The spring growth consists of large vessels; whereas in summer growth, the pores are relatively small. In a slow growing tree, due to the higher proportion of spring growth, the heartwood is less dense, softer, and accumulates more phenolic extractives. It should be noted that less dense wood would be easier to work, and therefore would be preferred by the cooper. Heartwood from a fast growing tree would be more dense, harder to work, and would be lower in extractives.

SOME IMPORTANT POINTS
1. Summer wood is invariably more dense than spring wood.
2. The faster growing tree has less extractable phenols than the slower growing tree.
3. On the average, European oak has a higher amount of extractable phenols.

Variation Due to Genetic Differences
Botanically, oak belongs to the genus Quercus. There are many species in this genus; however, only a small number of them are used in barrel making. From a winemaker's point of view, there are two major groups of oak: North American oak and European oak.
These two groups exhibit considerable differences in heartwood composition. American oak contains higher amounts of odorous compounds such as vanillin and oak lactones than the European oak. On the other hand, European oak contains more total extractables, and particularly twice the amount of extractable phenols than American Oak. A wine stored in American oak is likely to have a more pronounced “oaky” aroma and less tannic character. As the barrels are reused, the differences in wine stored in the American oak and European oak become less obvious and difficult to detect. There is no consensus among winemaker’s preferences, the style of wine, and the economic considerations.

Sources of Oak and Their Significance

Oak is widely distributed throughout the temperate regions of the Northern Hemisphere and in certain parts of the subtropical and tropical regions of the world. Oak used in barrelmaking belongs to the genus Quercus
which includes over 300 species. Of this large number of species, relatively few are used for cooperage. American Oak The American white oak grows over a wide area of the Eastern United States. The oak forest extends from the Canadian border to the north and the Gulf of Mexico to the south; from midwestern states such as Iowa, Missouri, and Arkansas to the west, and to the Atlantic Coast to the east. The main species of oak in the U.S. is Q. alba, and it constitutes about 45% of the standing timber. Other species that may be used in barrel production include Q. prinus, Q. bicolor, Q. mueh. lenbergi, Q. stellata, Q. macrocarpa, Q. Iyrata, and Q. durandii. Q alba is widely distributed over the area mentioned previously and is best suited for making barrels. Other species are not as widely distributed as Q. alba.
For example, oak wood obtained from Missouri, Kentucky, and from the northern part of the U.S. is more likely to include Q. bicolor and Q. macrocarpa;
The staves obtained from Arkansas and the South are likely to have come from Q. prinus and Q. Iyrata.
Staves made from Q. alba and other species are difficult to distinguish.
It is more realistic to assume that American oak barrels are made from largely Q. alba and to some extent, other species.
Since the influence of American oak barrels, as a group, on the sensory attributes of wine is fairly consistent, it is safe to assume that the chemical and physical properties of oak wood from other species is similar to Q. alba.
In the United States, barrel production is geared towards the needs of the whisky industry.

The so-called bourbon barrel, when used by the wine industry, did not give satisfactory results. Nowadays, many coopers are making wine barrels from American oak by using traditional French coopering techniques. These include air drying the wood, bending staves using wood fires, and wood fire toasting slowly over a relatively long period, to achieve deeper penetration of heat into the wood. French-style American oak barrels have yielded very encouraging results and more winemakers are using them for maturing their premium wines. Some winemakers are also experimenting with American oak barrels, using much thinner staves and using wood obtained from specific locations, such as Minnesota or Missouri. These experiments will yield some information that can be used in selecting and buying barrels.

However, a lot more research needs to be done in order to assist the winemaker in making the proper selection of barrels that would be suitable for maturation of various styles of premium wines.

European Oak
The oak wood preferred in Europe to make barrels is derived from two species viz Q. robur and Q. sessilis. These two species are known to grow in most of the European forest. Q. roburis reported to be more widely distributed than Q. sessilis. In many regions they grow side-by-side and easily hybridize. Q. robur seems to grow well in heavy and more moist soils. The wood is generally denser than in Q. sessilis, and the branching of the trunk occurs at a lower level. Q. sessilis, on the other hand, tends to grow in shallower soils and the tree trunk is tall and slender, with fewer low branches. For this reason it is preferred for reforestation in France.

French Oak
About 14 million hectares of land area in France is forest and about one third of this forest (about 4.5 million hectares) is in oak. The predominant species of oak are Q. robur and Q. sessilis. Other oak species of lesser significance include: Q. afares, Q. macranthera, Q. longipes, Q. imeretina, Q. iberica, Q. pedunculiflora, Q. lamugnosa, Q. farnetto, and Q. mirbeckii. There are four principal oak growing regions which supply the wood for making wine barrels. Center of France - This region includes the departments of Nievre and Allier, and a specific forest in Allier known as Troncais. The oak from this region is sometimes sold under the name of Nevers, Allier, and Troncais. The wood is tight grained and the species of oak grown in this region is mostly Q. sessilis.

Limousin
Limousin oak comes from the southwest area of France near the city of Limoges. It is close to the cognac region. The predominant species is Q. robur. The wood is wide or open-grained and more porous. It is richer in tannin than the wood from the center of France and is popularly used by brandy producers. Vosges This region is west of Alsace and northeast of Burgundy. The wood is tight-grained and relatively less dense, and close in character to the wood produced in the Nievre and Allier regions. The barrels made of oak from the Vosges region are popular with Burgundy producers.

Bourgogne
This area consists of the forest east of Burgundy. The wood is somewhat similar to the oak produced in the center of France. Traditionally, the wood is used by the Burgundy producers. There are other areas in France that supply oak wood. It is important to realize that the oak forest regions are not well defined and the origin should be considered as broad, general areas. In addition to origin, the French coopers and many winemakers also consider the grain of the oak wood as an important criterion in making a buying decision. For example, wide-grained vs. tight-grained wood should be considered. The grain reflects the growing conditions of the tree. A slower growth of the tree will result in tighter grain.

The genetic makeup of the tree will also determine the grain of the wood.
For example, Q. robur usually produces a wider-grained wood than Q. sessilis. There are several other conditions such as soil, climate, age of the tree, rate of growth, and location of tree in the forest that affect the grain. Even in the same tree, staves made from the bottom or top portion of the wood show differences in grain. Although the source (origin) of the wood and the grain are important considerations in buying barrels, one needs to realize that they may not be the most crucial factors to consider. Species of oak, method of seasoning the wood, and barrel manufacturing techniques are more important factors that would affect the quality of wood, and consequently, the wood's impact on the quality of the wine.

American versus European Oak
The question as to which oak is ideally suited for aging a given wine is a debatable point. Winemakers do not always agree on using a certain kind of oak for a particular type of wine. The choice of oak wood, in many cases, is a matter of preference. In order to make an intelligent choice between American versus European oak barrels, it is important to understand the differences in the composition of the two woods.
Generally, the American oak has a higher concentration of odorous compounds such as vanillin and oak lactone (trans- B-methyl-y-octalactone) than European oak.
On the other hand, European oak contains one and one-half times more extractable solids and twice the amount of extractable phenols than American oak.
Reference
Singleton V.L. 1974. Some aspects of wooden container as a factor in wine maturation.
Chemistry of Winemaking. A.D. Webb, editor. p. 265. *Previously published in Vineyard & Vintage View, Mountain Grove, MO.

There now. you have most of my knowledge of wood for barrels. I hope this is of help to all or some.

[Truckinbutch]

You , sir , are a treasure trove of information Glad you are willing to share with us .

[Jimbo]

Thanks for posting Scout. Good stuff

[S-Cackalacky]

Fascinating stuff. I've always thought of coopering as a technically complicated feat of woodworking. To master the science of it would also seem to be quite an accomplishment.

Thanks for posting this,
S-C

[Woodpile]

That was excellent - thanks!

[rumplestiltskin]

That was great. Verrry interesting.

[OlympicMtDoo]

WOW!! very good, a great pile of knowledge to add to the endless store house here. Thanks scout.

[Imgone]

We have a lot of Oregon white oak here in the north west. It's hard to come by because it's protected, but I picked a bit up from a home owner that had one fall down. Do you know if this is a good species to age with?

[scout]

We have a lot of Oregon white oak here in the north west. It's hard to come by because it's protected, but I picked a bit up from a home owner that had one fall down. Do you know if this is a good species to age with?

That is species Quercus Garryana and is a great stave wood. The trees are very slow growing which is the first thing to look for in suitability for stave wood. I'd use them any time I could get them.

[Imgone]

Good to hear Scout! I have a little saw mill so I traded labor for the raw material to rebuild an old apple press. I'm really happy it lends it's self to varying aspects of this hobby. Best Regards and Thanks for the comment.

[scout]

glad to be of help

[bearriver]

Don't go anywhere scout. HD needs a Cooper.

[scout]

oh I plan on staying around and I will be putting up a how to build your own tights, will probably be at least a three part series when I can get to it.

[Hound Dog]

Do you know if the white oak that grows in the mountain areas of Virginia and West Virginia (think Shenendoa Valley VA and Harper's Ferry WVA) are the right species of white oak to use? I just had to drop a huge white oak that was leaning dangerously toward my home after a recent wind storm. It took out two other small 8" - 10" white oaks on its way down.

[rbw65]

Well and good for WINE, but not Whisky. What does Scotland use? Used American Bourbon Oak barrels. What do American Whiskey Distillers use for aging? Why it is good ole American White OAk. But you can use any wood for aging to achieve different profiles. Try Wine staves, Scotland is using French Oak and Rum Barrels for finishing the aging process. I do not use chips, I use staves from Jack D or wine staves from Home depot that are from US wine makers. These staves are well used with a coat of Wine deep into the wood. It turns the Whisky pink.
Have fun aging and sipping the results.

[scout]

Hound Dog, yes that white oak is good stave wood.

rbw65, Scotland makes Scotch and for that very particular beverage they use sherry casks or at least they did up until the 1970's. Now they import U.S. wine barrels from California to age the Scotch in. The reason is purely financial, French casks have gone up like rockets in costs. Rum barrels are a poor substitute for aging scotch and are not allowed for any product labeled Scotch. Used staves from JD or anyone else are great to use (if you can find them George D. staves are really good I hear. What ever you decide to use, the sippin is sure to be fine.

[Due51]

That is a remarkable bit of information. Thank you for posting.

Last year I cut off a limb of white oak from here in Michigan (I believe it to be swamp white). I stripped the bark off and dried the limb in my utility room near the furnace. I split into 1 x 1 x 6" sticks, toasted in the oven, and charred with a torch. They are now sitting in 1 gallon glass jugs of bourbon in my attack. After reading your post, I fear I may have ruined my bourbon due to my lack of knowledge about oak and strains and spring/summer wood and heartwood.

How can I be sure to select the right tree/limb to use for future aging? Where can one buy Q. alba for home use?

Thanks again.

[der wo]

How can I be sure to select the right tree/limb to use for future aging?

If you buy barrel staves or JD smoking blocks, you know they are suitable for aging. The right sort of wood and well seasoned.

[scout]

That is a remarkable bit of information. Thank you for posting.

Last year I cut off a limb of white oak from here in Michigan (I believe it to be swamp white). I stripped the bark off and dried the limb in my utility room near the furnace. I split into 1 x 1 x 6" sticks, toasted in the oven, and charred with a torch. They are now sitting in 1 gallon glass jugs of bourbon in my attack. After reading your post, I fear I may have ruined my bourbon due to my lack of knowledge about oak and strains and spring/summer wood and heartwood.

How can I be sure to select the right tree/limb to use for future aging? Where can one buy Q. alba for home use?

Thanks again.

first thing to do is give a piece the "blow like a straw" test, true white oaks will not let you blow bubbles through them (red oaks do). Second test can only be done with a tree in leaf, a white oak has round lobes on the leaves, red oaks and other unsuitable oaks have points or near points on the leaf lobes. Color of the wood is not a good indicator, many times a white oak will have red tinted wood and red oaks can appear quite white to deep red.

While there are species considered to be the best or better ones for cask making (charred stick, etc.) all will work ok. I would always do a sniff test before char and after char, an unsuitable wood will smell, well nasty to put it simply.
Good woods will smell sweetish, with a clean, burnt smell (after the char of course). Unsuitable woods will smell like dirty socks or you will detect an odor that will make you want to say EWWWWWWWW.

As has been offered up, if you buy used stave wood, you know what you are getting and it will be good stuff. You can buy Q. alba in stores like Home Depot but a specialty wood store is a far better place to get "store bought".
I've actually bought complete barrels from JD, George D. and Evan W. all are good wood and since most folks can get broken down casks in the form of staves for a much cheaper costs than buying a complete casks, it makes good sense to do that, especially if you question whether or not a particular piece of tree is good for our purposes. Always better to know for sure than to do the second guess after you have a batch on the wood.

[Due51]

How can I be sure to select the right tree/limb to use for future aging?

If you buy barrel staves or JD smoking blocks, you know they are suitable for aging. The right sort of wood and well seasoned.

I do use those smoking blocks for my whiskey, but I was trying to make a genuine* bourbon using new toasted and charred American White Oak.

*realizing I'm not making it in Kentucky.

[Due51]

first thing to do is give a piece the "blow like a straw" test, true white oaks will not let you blow bubbles through them (red oaks do). Second test can only be done with a tree in leaf, a white oak has round lobes on the leaves, red oaks and other unsuitable oaks have points or near points on the leaf lobes. Color of the wood is not a good indicator, many times a white oak will have red tinted wood and red oaks can appear quite white to deep red.

While there are species considered to be the best or better ones for cask making (charred stick, etc.) all will work ok. I would always do a sniff test before char and after char, an unsuitable wood will smell, well nasty to put it simply.
Good woods will smell sweetish, with a clean, burnt smell (after the char of course). Unsuitable woods will smell like dirty socks or you will detect an odor that will make you want to say EWWWWWWWW.

As has been offered up, if you buy used stave wood, you know what you are getting and it will be good stuff. You can buy Q. alba in stores like Home Depot but a specialty wood store is a far better place to get "store bought".
I've actually bought complete barrels from JD, George D. and Evan W. all are good wood and since most folks can get broken down casks in the form of staves for a much cheaper costs than buying a complete casks, it makes good sense to do that, especially if you question whether or not a particular piece of tree is good for our purposes. Always better to know for sure than to do the second guess after you have a batch on the wood.

Thanks Scout. I made sure I chose a leaf with rounded lobes. It's for sure a white oak. I'm just not sure if it's Swamp white or American white.

I appreciate your response.

[der wo]

How can I be sure to select the right tree/limb to use for future aging?

If you buy barrel staves or JD smoking blocks, you know they are suitable for aging. The right sort of wood and well seasoned.

I do use those smoking blocks for my whiskey, but I was trying to make a genuine* bourbon using new toasted and charred American White Oak.

*realizing I'm not making it in Kentucky.

You are right. But about taste, if you made sticks from the staves, only a little part of it is used, the most is unused.

[Due51]

You are right. But about taste, if you made sticks from the staves, only a little part of it is used, the most is unused.

True. Sometimes I get hung up on the details and can't see outside the box. If the definition calls for new, I have a hard time taking my sights off "new" even though I put myself at risk of using the wrong wood. The stuff I have aging in the attack is coming up on a year old. If I don't like the smell or taste, I'm going to take out those oak sticks and throw in some JD smoking blocks.

[Secale]

I have a question about wood used for making aging barrels.

Has anyone ever made a single barrel with two different woods?

For example:

An white oak barrel made with maybe a few staves of sugar maple.
          Sugar maple is sweeter than oak and I suspect this would change 
          the flavor of the end product.

Blended barrels?

OMG: Look at the size and price of these barrels.

http://www.thevintnervault.com/product/ ... on%29.html" onclick="window.open(this.href);return false;" rel="nofollow

[rad14701]

I have a question about wood used for making aging barrels.

Has anyone ever made a single barrel with two different woods?

For example:

An white oak barrel made with maybe a few staves of sugar maple.
          Sugar maple is sweeter than oak and I suspect this would change 
          the flavor of the end product.

Blended barrels?

White oak is used because of its closed cell properties that even red oak can't claim... Very few types of wood have closed cells that inhibit leakage... Sugar maple would not be a good choice for this very reason... White Oak, French Oak, and a very few others would be considered suitable...

[Secale]

There's lots of northern red oak here. I could go out and cut a nice branch to make sticks or chips.
But unfortunately, it's way too rich in tannic acid from what I've read to age with.

[rad14701]

There's lots of northern red oak here. I could go out and cut a nice branch to make sticks or chips.
But unfortunately, it's way too rich in tannic acid from what I've read to age with.

If you're talking sticks, cubes, or chips, you can try just about any wood... Making a barrel is a totally different story... I doubt you'd like what red oak would do to your spirits due to the excessive tannins... I have some apple wood seasoning at the moment that I hope to use for aging but that will be a story for another day...

[kiwi Bruce]

Very good post here Scout.. worlds of info. Thank you SOOOO much ! ! Kiwi

[DAD300]

Has anyone ever made a single barrel with two different woods?

For example:

An white oak barrel made with maybe a few staves of sugar maple.
          Sugar maple is sweeter than oak and I suspect this would change 
          the flavor of the end product.

Not that I've seen, but even the big boys are trying using dif woods after the initial oak.

[Secale]

All I found is a hybrid barrel made with French oak heads and American oak staves.

http://www.worldcooperage.com/library/d ... Barrel.pdf" onclick="window.open(this.href);return false;" rel="nofollow

The only thing I can think of also is placing another type of wood inside a regular oak barrel.
i.e maple,cherry,apple,etc. wood sticks for flavouring.

I'm just reading all this oak stuff and getting lots of ideas.

Some are bound to be wacky so don't mind me.