Everybody I know in the wine industry turns up their nose at things like shavings, chips, chunks, and spirals etc., of oak preferring the use of the oak barrel and most of them are persnickety about what oak it is, where it comes from, and even how the oak is split. The finest barrels are not made from staves that come off a lumber mill's saws, but are rift split with a splitting tool that follows the natural grain of the wood. (Chair makers prefer this also because the wood is stronger). The oak they prefer comes from tended forests in a specific part of France where the soil provides just the right minerals and nutrients and the certain species of oak is carefully tended over the centuries to obtain just the right quality of lumber then air seasoned ( never Kilned) in protected open air sheds.
Bit even the cheaper barrels used in lower grade wine and liquor industries insist on Rift or Quarter sawn staves and not slab or flat sawn.
The reason for this preference is all about what edge (what part of the grain) of the board is presented to the liquid. The wrong edge allows the wrong things to leach out of the wood into the wine or spirits.
They all say the same thing about those cut up or shaved oak products that one might add to a tank: That they expose the wine to the wrong parts of the oak whereas the barrels (with correctly produced staves) don't. Apparently there are host of things in the oak that can leach out into the wine that are not desirable, but that the right oak presented to the liquid the correct way will allow the vanillans and desirable wood sugars and such to leave the wood and enter the wine while the undesirable elements tend not to.
Of course this leaves unanswered the question of what happens to beer exposed to oak in any fashion for the short time one might during a ferment or even in the keg. Wine and spirits sit on the wood a hell of a lot longer in oak barrels than beer does. So the whole leacheate question may be different.
What it does for me, is informs me that there may be negative factors contraindicating the use of oak products in my beer. ERGO: I wouldn't use it and certainly I'd not use a sawdust product of for no other reason the surface area of sawdust would provide too much surface area exposing my beer to too much of the side of the grain that offers too great a chance of negative flavor compounds. I think the saw dust is just something that some one in a marketing department somewhere thought up as a way to make money from a waste product.
The money they can make selling sawdust to hobby brewers certainly has to be better than what they'd get selling it to wood stove pellet makers.
Here is some more information about coopering for the liquor industry.
http://www.worldcooperage.com/page.asp? ... d=vid_homehttp://seguinmoreaunapa.com/resources/c ... g-process/http://www.louislatour.com/pages/index.php?id_page=74
