How can you tell that a bottle has cork taint? Unless you know what the wine should taste like ahead of time (e.g. it's your favorite wine and you know how it should taste), or you recognize the smell of cork taint, you may think that the bottle was just not very tasty, or the wine critic that praised that wine doesn't know what they are talking about. The problem with cork taint, is that there are different levels of taint. A very slight taint is the hardest to detect and usually just is represented by a flatness in the fruit flavour and aroma. With more cork taint, along with the reduced fruit flavour and aroma, you may smell wet cardboard or freshly dug potatoes.
Cork manufacturers have been trying to produce better cork with fewer defects, but there are still rivals to traditional corks, being synthetic (plastic) corks and the stelvin closure. In a previous blog post I talked about an alternative to cork, which is the stelvin closure. You may want to check it out.

You will also notice difference in length. Longer tends to be better for corks, as there is more separation between the wine and the air outside of the bottle. The agglomerated corks are basically bits of cork that fall off or break off in the cork making process. These bits of cork are broken down into pieces of about the same size then glued together. These corks do not look very nice, but get the job done. Some winemakers go for the agglomerated cork sandwiched with slices of real cork. The Mission Hill cork in the photo has a real slice of cork about half way through the M in Mission and then at the last L in Hill. Some people prefer this cork over the simple agglomerated cork, as there is a real piece of cork in contact with their wine as it ages as opposed to wine + glue. Finally you have the single piece of cork. This is the ultimate goal for many winemakers. The better cork would have the least amount of holes/pits visible in the cork. The Pisano cork has more holes/pits visible on the cork, which could be housing cork taint, or could let too much air interact with the wine, making it age quickly. The longer Montes Purple Angel cork (leftmost cork) is an example of a high quality single piece cork. You do not see lots of small holes along the sides of the cork.
Well now you know a bit more about cork and about cork taint. The next time you open a bottle of your favorite wine, check out what type of cork they are using. If you wine smells off, as described above, and you are in a restaurant, please don't hesitate to talk to your server and ask for them to confirm with you that the wine is corked. If it si, they should give you a replacement bottle at no additional charge. It's your money and enjoyment. Cheers!