Cider making is generally quite straight forward and a lovely tasting cider can be achieved with very little effort however depending on the apples you are using you may need to adjust acidity levels, sweetness and tannin.
Acidity in your cider
The acidity is usually determined by the variety of apples used, traditionally apples that are similar to wild crab apples are considered perfect for making cider. However your juice can be altered when you first collect the juice from the apples. This can be done in a small quantity first, just a cup full, you can then check the taste and check the ph with an acid testing kit. Be careful not to use ph testing kits for soil as these are not accurate enough. Acid gives cider it's crisp taste so without it the cider would lack flavour it is essential to have some present for a good quality cider. It is also essential for fermentation as a cider with low acid and a high ph will make it susceptible to bacterial infections at the early stage of fermentation. The ph you are looking to achieve is between 3.2 - 3.8. The rule is that as the acidity goes up the ph goes down and vice versa.
Lowering the acidity
Precipitated chalk will lower the acidity add approximately 1 teaspoon per gallon, it will reduce the acidity by 1½ parts per thousand. Make sure you have enough head room in your fermenter as it froths up quite a bit when added. Be careful not to over do it and if you don't have an acid testing kit keep tasting until you have the correct flavour, keep in mind that there should always be a slight flavour of the acid coming through. You can also blend your juice with another which is lower in acidity which should help to bring it down too.
Malic acid is found naturally in apples and will increase the acidity. Add approximately one teaspoon per gallon and again as above be careful not to over do it and keep tasting it or test it with an acid kit until the desired flavour/ph is reached.
Add one level teaspoon per gallon to increase the levels of tannin, tasting as you go so that you don't add too much. To lower the level of tannin finings can be used as the tannin particles are usually negatively charged, adding particles that are positively charged results in them sticking together they then sink to the bottom of the fermenter. There is more information on using finings in your cider here:
Adjusting the sweetness
I like cider to be sweet in which case adding sweetener or apple juice to your brew at the end of fermentation will increase the sweet flavour. Rack off the cider into a secondary fermenter and add the sweetener or apple juice until the desired flavour is achieved. The sweetener will not ferment but the apple juice will so it's worth adding campden tablets to stop any vigorous ferment. The dosage is one crushed tablet per gallon.
To ferment to dry cider you need to allow the ferment to progress fully. If you're racking the cider off into another vessel for a secondary ferment you can add some granulated sugar, 170 grams per gallon, this will not increase the alcohol much but it will produce an average strength cider which tastes great. Remember to make the sugar into a solution first with just a small amount of water before adding to the secondary vessel. Top your fermenter up to just below the lid/bung and move to a warm place to ferment again. Once the hydrometer reading is stable over 48 hours it can then be bottled.
Carbonating your cider
Adding sugar once fermentation is complete either in the bottles or in a secondary fermenter will add fizz to your cider. We recommend 2 heaped teaspoons or 2 to 3 carbonation drops in each bottle depending on personal preference. Alternatively you can also batch prime using sugar we recommend about 110 - 150 grams of sugar per 23 litres, to do this make up the sugar solution with enough water to liquidize it, allow to cool, then add to your secondary fermenter, once this is done you can syphon your cider onto it and then transfer to bottles. Be careful to avoid any splashing or exposure to oxygen. The bottles then need to be positioned in a warm place at room temperature to kick start carbonation which should take between 2 and 4 weeks.
Another more purist way of carbonating you cider is to transfer it to the bottles just before fermentation is complete. However it is difficult to predict how much carbonation you will achieve and at what point towards the end of fermentation to transfer it. You would need to monitor the brew with a hydrometer, generally you would need to bottle once the reading is approx 1.010, although this isn't an exact science and would require some experimentation. If you are just starting out on your cider making journey I would recommend the first carbonation method above.