The Importance of a Good Cork

It is a good day to write a little bit about the importance of a good cork when bottling wine. It is a Saturday, the store is open but not yet busy, and on Monday I will be getting in a shipment that includes WinExpert wine kits, winemaking equipment and home brew supplies. On Tuesday I am expecting in the second shipment of Cellar Craft wine kits in the last week. These two shipments might must keep me too busy to write blog articles so best get it done today.

I know there are many home wine making people out there and you use a number of different kinds, styles, lengths, and diameters of corks when you bottle one of your Cellar Craft or WinExpert kits or some of your backyard fruit wine. When people are in the store my criteria for helping them select corks initially centers on what type of corker they own or wish to purchase. If they own (or want to purchase) a plastic hand corker (or what I call the brute force method of putting a cork in a bottle) I recommend either the #7 or #8 diameter corks. The #7 corks are the smallest diameter corks and are also the lowest quality. The #8 corks are a medium diameter cork and are of marginally better quality. Why do I recommend these two corks if they are of lower quality? Mostly based on the corker itself. The #9 corks are the largest diameter corks but are virtually impossible to insert into a bottle using this corker. The #7 and #8 corks also have chamfered ends which assist in insertion. We do sell one style of #9 cork with chamfered ends but these are of the same grade as the #8s.

The next choice in corkers is to purchase either a Portuguese or Italian double lever corker. They operate on the same principle (tapered sleeve for the cork to slide through prior to insertion) as the plastic hand corker but instead of pounding on the top of the corker with your hand or a rubber mallet, you pull two levers apart which in turn drives a plunger downward which pushes to cork through the tapered sleeve and into the bottle. Do they work well? No! I personally like the plastic hand corker better. Do they work with a #9 cork? Maybe if you are Hercules!

If your hobby is important enough to you to own a floor corker then the choice of corks comes down to style and quality as opposed to diameter. A floor corker will insert a #9 cork into the bottle easily. Pick the quality cork that you need based on the length of time your wine will be in the bottle. Cork choices range from first quality corks (these are the same grade as the #8s) to winery grade twin disc which are an agglomerated (compressed ground up cork) cork with a disc of natural cork on each end to Altec corks which are agglomerated suberin (this is the highest quality cork available) to synthetic corks. I personally use either the twin disc corks or the Altec corks for bottling our wine here at the winery.

So what is the importance of a good cork?

The whole purpose of the cork is to establish closure. Closure to me is defined as the ability to seal the bottle so that air does not transmit from outside the bottle to inside the bottle. Please do not believe anyone who tells you that a cork breathes! This would imply that air passes through the cork and this simply is not true! Air can pass by the cork if your cork is of a smaller diameter or if it is damaged in some way or if your corking process puts a crease down the side of the cork. If corks did breathe then I would not be in the business of making wine. I would be in the business of making a liquid that had a taste similar to vinegar!

If wine does aerate because of a poor quality cork or a leaking cork the wine will oxidize and in turn it will lose the protection of the free SO2 (sulphites) and then the tannins, pigment and polyphenolic protections of the wine will leave followed by the loss of flavor and discoloration of the wine.

My advice is to purchase the very best corker that you can and then purchase the very best corks to put in your wine bottles. Lots of cork shoved into a very small space makes for longer lasting wine.

Not to forget our beer brewing customers, BlueStem Winery carries a complete line of homebrewing supplies, homebrew ingredients, and home brew equipment in addition to our fine line of WinExpert and Cellar Craft kits and other home winemaking supplies. Our beer brewing supplies inventory has grown significantly and we look forward to serving either your home brew or wine making hobby!