One of the most popular questions we get asked is “What wine cork should I buy?”

Depending on the manufacturer and supplier, wine corks can come in various types and names. Below is a breakdown and explanation of the more popular styles which are available at Brew Craft.

The #9 size cork is the most common option for almost all wine bottles in use and are the ones assumed to be talked about below.


The Agglomerate cork is a wine cork closure made of natural cork granules. The NovaCork is made from cork granules that range from 3mm to 7mm.  These granules are moulded into a straight cork of specific size with the use of a synthetic silicone glue. The characteristics of agglomerate cork differ from natural wine corks in production methods and visual appearance. Similar to natural corks, the Agglomerate cork has high resistance and offers a fairly good seal and is therefore preferred to more expensive synthetic substitutes. Due to its composite construction, seepage of wine may occur but this is very seldom. These corks are not intended to replace good quality natural wine corks, which remain the best option for a good quality bottle seal. All of the Agglomerate corks available at Brew Craft are silicone treated for ease of insertion and removal.

It is recommended to use the #9 Agglomerate corks in bottles of wine that you plan to enjoy within approximately 18 months.  Depending on the type of storage, any longer than 18 months may cause damage to the wine.

Brew Craft also carries the #8 long Agglomerate cork.

The #8 long Agglomerate cork can be used in standard wine bottles, but for short term storage only. They offer ease of insertion and extraction, but due to the initial smaller diameter of the cork, they do not offer a well sealed bottle which is necessary for storage that lasts longer than 6 months.

Due to the ever increasing availability of bottles that have smaller neck diameters, it is recommended to check the size of the opening in your bottles and sort them according to the size of the inside diameter of the opening.  Depending on the actual neck diameter, it may be necessary to use a #9, #8 or even a #7 size cork.

Due to the small particulate size, and the smaller the particulate size the more pronounced the problem, a piece of cork may fracture off and fall into the wine bottle if the corkscrew pierces the bottom of the cork. The NovaCork, being made from a larger particulate size, lessens this problem.


The Diamond cork is a straight chamfered wine cork which is punched, at a specific size, directly from a flat sheet of natural cork bark which has been steamed flat. The punched stopper is then cut to its proper length.

The stoppers are then optically sorted into different grades of cork.  They are then washed in an automated system using a hydrogen peroxide based solution from which they get the term BWC [bleached without chlorine]. The corks are then dried in sterilized air and sorted manually into finer classifications.

Diamond corks can be colmated, that is having all the grooves, ridges and holes filled with a cork dust and silicone based adhesive, or left all natural with the holes and grooves visible. Either way, the performance of the Diamond cork is not compromised. The collimation process is generally only for decorative and astetic purposes.

It is recommended that the Diamond cork be used in bottles for longer storage of wine.

#9 long Diamond XXX is to be used for a three year wine storage.
#9 long Diamond XXXX is to be used for a five year wine storage.
#9 long Diamond XXXXX or Winery grade is to be used for a ten year wine storage.

All Diamond corks are silicone treated for ease of insertion and removal.


The synthetic cork is a wholly man-made stopper. These wine corks are constructed from a foam plastic core and a denser outer casing which are sized specifically for standard neck opening sizes.
There are two main styles of synthetic corks. One is extruded in long sleeves which are then sliced into the proper length.  This process exposes the foam inner core at each end of the stopper.  The other process fully encapsulates the foam inner core in the more dense outer casing. It is the latter synthetic stopper which is available at Brew Craft.

Many people falsely believe that this stopper is re-usable. It is a One-Time-Use stopper, and when it is pierced with a corkscrew or cork puller, it’s sealing ability is impaired.

These corks are expensive, but they do have the advantage of allowing vertical storage of your bottled wine.

NOTES: (1) Due to the different bottles available on the market, it is recommended to take a couple of minutes to check the necks on your bottles before bottling. Trying to insert a cork into a smaller diameter bottle neck than intended can cause excess pressure on the neck and may cause the bottle to break and cause injury.

(2) The time limitations stated above for the various corks are approximations only. The quality of your wine, the storage conditions and environmental factors will all effect the actual storage limitations of your wine. It is generally true to say, however, that the better the wine cork you use, the greater protection that is afforded to your wine.

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