|Category||Fermented food recipes|
|Servings||About 2 litres|
|Time||prep: 1 hour
ferment: 2-3 months
Cider vinegar - also apple cider vinegar, ACV, is a type of vinegar made from apples. Cider vinegar has a unique flavour, coming from the apples used to make it. Some recipes require cider vinegar, although other vinegars may be substituted.
Being made totally from apples, cider vinegar is gluten free unlike, say, malt vinegar. However, some commercial brands add wheat-derived substances such as caramel (as colouring), so it is important to read the labels when purchasing.
Cider vinegar isn't hard to make; in fact, it's easier to make cider vinegar than it is to make cider! The basic procedure is to make cider from fresh apples, but use no preservatives and keep the lid open to let oxygen in. A recipe follows.
- 4kg (8 lb) fresh apples
- two 3 litre fermenters (can be large bottles or food-grade plastic buckets)
- apple crusher or juice maker
- food-grade siphon hose (from hardware store or homebrew shop)
- Wash the apples to remove obvious dirt, and cut out any bruised or bird-struck bits.
- Crush the apples, or put them through a juice maker, and collect the juice in one of the fermenters.
- Cover the fermenter with a cloth, or plug the opening with cotton wool if narrow, to keep out dust and insects. Don't worry that the fermenter isn't full, as it should be for making cider. With vinegar, air space is good, as it brings oxygen to the bacteria.
- Set aside somewhere to ferment, not too warm or too cool (about 18-22°C / 64-72°F is best).
- Allow the juice to ferment. It should start getting bubbly within a couple of days. Note the progress, so that you can tell when fermentation has peaked and is slowing down.
- When the fermentation is slowing down and not bubbling so vigorously, siphon into the other fermenter carefully. Try not to get too much of the gunk that has settled to the bottom, or the froth on top - the aim is to get a clear cider without too many floating chunks!
- Set the second fermenter aside to ferment for two to three months. After a while, you should see a white film forming on top. Don't despair - this is the vinegar mother, a structure built by the vinegar-making bacteria (acetobacter)
- After a couple of months, you can draw off two thirds of the vinegar for use, and top up with fresh, clear cider made in the first fermenter.
Notes, tips and variations 
- Use only glass, stainless steel, or food grade plastic when making cider vinegar. The acids in apple juice, and further created by fermenting to vinegar, will leach chemicals from other plastics and corrode some metals.
- Cider vinegar is better when made with a blend of apples including cider varieties - e.g. sharps and bitters, not just sweets - but pretty much any apples will do.
- Apple juice that is free of preservatives can be used instead of crushing fresh apples. Just add yeast to get the initial fermentation going, and stir occasionally for the first two weeks to help encourage the acetic bacteria.