If you’re getting ready to buy corks to bottle your wine you may be wondering which size corks you should get. We offer four different sizes of wine cork stopper. They are sizes: #7, #8, #9 and #10. These numbers refer to the diameter of the cork. The higher the number, the larger the diameter of the cork.
The opening of a standard, 750 ml wine bottle is 3/4 of an inch. If you have a wine bottle corker you will want to purchase either the size #8 or size #9 corks. The diameter of these corks are 7/8″ and 15/16″, respectively. Size #9 corks is what the commercial wineries use. Either will require a wine bottle corker to press them into the bottle.
Which size cork you get depends on the type of wine bottle corker you have. Any wine bottle corker on the market can put in the size #8 wine cork, however some wine bottle corkers have trouble putting in a full-size #9 cork.
If the corker was purchased from E. C. Kraus, you will be able to put in a size #9 or #8 cork just fine. If your corker was purchased from somewhere else then some caution will be required.
Some wine bottle corks on the market use a funnel-design to compress the cork. The wine cork is shoved through a funnel into the opening of the wine bottle. For the most part, this design of corker will work okay for a size #8 cork, but if you want to put in a full-size #9 wine cork and get a tighter seal, using a funnel-style corker can be a problem. The larger cork can get pinched and frayed as it goes through the funnel.
All the wine bottle corkers we offer compresses the cork evenly, from 
all sides then plunges the cork into the barrel opening of the wine bottle. With this method of corking no damage will come to the cork, as it is not be contorted through a funnel opening.
We do not recommend using size #7 cork, but we do offer them for individuals who want to put their corks in by hand. This size wine cork is small enough in diameter to be put in without a wine bottle corker. The downside is that they do not seal the wine bottle very well. In fact, if you lay the wine bottle on its side, there is a fair change that the #7 wine cork will seep some wine. For this reason you should store wine bottle upright if using this size of wine cork.
Size #10 corks are for larger size bottles. While many larger bottle still have the same 3/4 inch opening that the 750 ml have, some larger size wine bottles have larger openings that will require this larger size cork.
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Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.
What size cork do you use for 750mm bottles from Perrier water?
I am making wine stoppers for gifts what size cork do I need for an opened wine bottle. Thanks Patty
No one mentions the length of corks
Patty, I am assuming you are referring to tapered corks and not straight corks. We normally recommend an size #9 for this purpose:
#9 Tapered Corks
http://www.eckraus.com/9-hand-select-tapered-cork.html
What size corks should be used with port bottles?
Julie, if the port bottle has the standard 3/4 inch opening so you can use the #8 or #9 size corks. You may also want to consider the plastic wine stoppers for your Port.
Wine Bottle Stoppers
http://www.eckraus.com/reusable-wine-bottle-stoppers-100.html
What corker does one use with #10 size corks
John, you can use any of our floor or bench model corkers for the #10 cork. We do not recommend using the hand held corker.
What size corks fits in a double magnum wine bottle? The hole measures 67.5 mm. Thank you
Tina, I don’t believe you will find straight corks to fit that large of an opening. You can try using a tapered cork or a rubber stopper. Just choose one that has a bottom diameter that is just slightly smaller than the opening.
I have some champagme to bottle in thick heavy bottles and have synthetic corks, and would like to know if I still have to know wire the corks in. Denis
Denis, We would recommend using the wires because the pressure in the bottle could cause the corks to pop out. I would also look at using the champagne stoppers as well.
Can I use a StarSan solution to sanitze and soften my corks prior to corking?
Mark, we would recommend steaming the corks or soaking them in a sulfite solution to prepare for bottling. For more information please see the article posted below.
Preparing Corks For Bottling
https://eckraus.com/wine-homebrew-blog/preparing-your-corks-when-bottling-homemade-wine/
Thanks for this question! StarSan is what I had planned to use. (I’m a novice, can ya tell? lol)
Using StarSan solution for cork soaking never got a yes or no. Is it ok to use for cork soaking prior to bottling. If not why?……………… Thanks
Benjamin, you do not want to use Star San to soak wine corks. Corks are porous and the description of the Star San says it is not to be used on porous items.
I am using the Portuguese Floor-Model Corker to cork my homemade wine. I am using a #9 straight cork. This model is wonderful, but a bit tricky to set the correct level for cork depth. Any hints/tips on how to do this and if the cork is a bit high (about 1/4″) above the bottle, can you push it down further or just live with it?
Gabrielle, you really do not want the cork sticking out of the top of the bottle. You can adjust the bottle height of the corker. All you need to do is simply pull the handle all the way up and you will be able to move the stand.In addition, make sure that you are soaking the corks before use, this makes them more pliable.
I want to sterilize my wine corks prior to bottling my wine. I have campden tablets and would like to know what the conversion to your mixture of 1/8 teaspoon of sodium metabisulfite to each pint of water. How many campden tablets per/pint of water would I need to use?
Marti, each campden tablet is 1/16 teaspoon. The dosage of 1/8 teaspoon is equivalent to 2/16 teaspoons, so you would need 2 campden tablets per pint.
How To Prepare Your Corks For Bottling
https://eckraus.com/wine-homebrew-blog/preparing-your-corks-when-bottling-homemade-wine/
this is how to calculate which cork is designed for Your wine;
if using natural cork, check diameter of Your bottle neck inside, than add 6mm, and go to higher No. for tipical bottle = 17,5 mm, 38/44/49/54 x 24 mm is optimal.
if using botle 18,5 mm, go for 38/44/49/54 x 25 mm.
if using microaglomaerated, instead odf 6mm, use 5 mm wider cork, since they cant shrink as natural;