The Easy Way
Any large vessel should work for this fermentation project. Stick to glass or pottery; avoid plastic and metal. Big Jars are perfect or a vinegar maker. Buy a bottle of apple cider from your grocery store. I recommend organic apple cider because it will produce a mother that allow you to produce vinegar faster. Sterilize the jar, pour the cider in and cover the mouth of the jar with cheesecloth, secure with a strong rubber band. Place it somewhere warm and dark like the cabinet above your stove. It will ferment quicker.
It takes between 2 to 4 weeks to complete the fermentation process. If you want to produce more vinegar and faster, let the mother (a viscous material floating on the vinegar) appears. The mother is constituted with the healthy bacteria that turn cider into vinegar. For your next batches, pour 1/3 vinegar and 2/3 cider and put the mother on the mixture. If you are using a vinegar maker, there is a tap. You just have to open it when vinegar is ready and let 1/3 of the liquid in the container. Then pour 2/3 of apple cider and start the process again and again.
At that point, you now want to store your vinegar unto bottles or jars. You can store it in your refrigerator but it is not necessary. Vinegar is very stable and will not ferment more. It is a porduct you can use for many years.
Easy Steps to Make Homemade ACV
1. Wash 10 organically grown apples.
2. Cut the apples into quarters.
3. Allow the apples to rest at room temperature until they turn brown.
4. Put the brown apple quarters into a large, wide-mouth glass jar.
6. Cover the jar with a cheesecloth. Allow it to rest lightly on top, without securing. This will let more oxygen into the mixture.
7. Place the covered jar in a warm, dark place. A hot water closet works well. You can also store it in an attic or well house during warm weather months.
8. Leave the jar to stand, covered for 6 months, stirring once a week.
9. Retrieve the jar at the end of the 6-month fermentation period. There will be a layer of scum on top of the liquid. This forms from normal bacteria as alcohol turns to vinegar.
10. Filter the liquid through the cheesecloth slowly into another wide-mouth glass jar. This can be done by holding the cheesecloth securely onto the first jar. Then tip it to let small amounts of liquid through and into the second jar. Do this until all the liquid is filtered and transferred to the second jar.
11. Cover the new jar of liquid with the same cheesecloth.
12. Let stand in a warm, dark place for another 4 to 6 weeks.
13. Transfer your fully-fermented Apple Cider Vinegar into smaller containers if desired. Store, covered, in the refrigerator to preserve freshness.
Sources: WikiHow, Grow Your Own Groceries