Oak barrels loose the ability to impart flavor after about 3 years of use. Each year after the first, the barrel will impart less influence on the wine until it becomes "neutral" and will not do anything more than allow for microoxidation.
You can have the barrels re-toasted and shaved but it's cost prohibitive. The best way is to utilize staves. Innerstave will put in new, toasted pieces into the barrel and you're good to go again. The only problem is the flavor. Innerstave cannot match the flavor of a good new barrel.
Another issue is, with time the pores of the barrel close up and you loose the micro-oxidation effect. Bacteria can also build up in the barrels.
Remember the old Italian and Spanish wines that were very funky? It's because they used barrels for years (5-15) and the microbial instabilities were passed from vintage to vintage.
Oak barrels allow the slow ingress of oxygen. And of course, there's a slight influence of metabolic reactions. For the past few years, we have been using only oak barrels now, but previously (due to some money related issues) we used glass bottles: the flavor and the taste are drastically different.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .