Tannin, acid and sugar – cider’s balancing act

The flavour of a cider is a combination of taste and aroma, which mainly comes from a blend of tannin, acidity and sweetness. Tannin and acidity give cider its palate-cleansing qualities; acidity particularly helps to cut through fattiness in food, while high-tannin ciders tend to pair well with high-protein foods. Sweetness mellows spice and balances rich foods such as pates or charcuterie.

The balance of tannin, acid and sugar in apples can affect the rate and nature of the fermentation and therefore the quality of the cider. Cider apples tend to have higher sugar levels and are more fibrous than dessert apples, making them easier to press. English and French cider apples also tend to have tannin levels. Tannin makes a difference to the colour, flavour and ‘pressability’ of the apple and is mildly anti-microbial. It gives cider much of its ‘mouthfeel’.

Cider has ‘terroir’, like wine

Cider is made from single varietals or, more usually, a blend of apples and, like wine, its complex flavours depend on ‘terroir’, a combination of the apple and where its grown. Devon, for example, has numerous native varieties of cider apple with names such as Fair Maid of Devon and Devonshire Quarrendon, in addition to its dessert and cooking apples. In Devon and West Dorset tastes have traditionally veered towards sharper ciders with lower tannin, whereas in neighbouring Somerset, ciders tend to be well-rounded but astringent.

Cider and food have a long tradition in this part of the world. Home-made cider, apple cakes and jams have been produced from our orchards since the 13th century.  As an ingredient, cider is surprisingly subtle and as likely to be used in light fish dishes as in robust venison casseroles, delicious puddings or even bread. Cider products such as cider vinegar and cider brandy add to its versatility. And as an added bonus, cider is gluten-free.

Tannin

Tannin is what makes cut apples go brown in the air. It is not the same as acidity. Tea is high in tannin; lemon juice is acid. Both are needed for balance, along with sugar. High-tannin apples have more body and bite (astringency) but they are also more fibrous and easier to press.

Cider made from culinary or table fruit are typically low in tannin whereas traditional English and French ciders made with bittersweet fruit have higher levels of tannin and are therefore relatively astringent and bitter. The desirable balance is in favour of astringency rather than bitterness; overt or forward bitterness is a fault in cider.

Acidity

Acidity is an essential component of cider and perry. It’s needed to give it the clean, refreshing taste that makes dry cider so good at cutting through fattiness and act as a palate cleanser. Acidity is not be confused with acetification; when a cider becomes vinegary its aroma is acrid and it tingles in the mouth. Nor when a cider is affected by air but without the intervention of microbes or yeast and the result is a sherry-like aroma.

Sweetness

A cider’s sweetness comes from unfermented or residual sugar, which can vary from less than 0.9% (very dry) to as much as a dessert wine. One method of achieving a naturally sweet cider is keeving in which the juice stands for several days in the cold. The ‘flying lees’ or chapeau brun rises spontaneously to the top and the clear juice between the ‘hat’ and the sediment is taken off and allowed to ferment very slowly for around three or four months, until repeated racking stops the fermentation. Sometimes, extra sugar is added before fermentation. Cider made with honey is cyser; in competitions its is classed with mead. Adding brown sugar, molasses or even raisins creates a New England-style cider.

Aroma and mouthfeel

Some of the volatile alcohol aroma of cider has the same chemical basis as that of other fermented drinks such as beer. And West Country and Normandy ciders made with bittersweet apples tend to have a spiciness that comes from chemicals (volatile phenols) that are also found in whiskies. But the specific, characteristic ‘green’ aroma of a cider comes from a chemical compound called a dioxolane that almost only occurs when apples are fermented. A cider with a very appley aroma is likely to be sweet and/or low alcohol. Drier ciders develop more complex characters that are more wine-like.

Carbonation lifts the flavour of a cider and provides greater perceived acidity. It can be either natural (by maintaining carbon dioxide pressure through processing or by bottle-conditioning) or added (by CO2 injection). It also affects mouthfeel. In general, cider and perry have a mouthfeel and fullness similar to that of a substantial white wine but less body than a beer. It shouldn’t be bland or watery.

It starts with the apple 

Cider can be made with most types of apple including sweet dessert or eating apples, tart culinary apples or cookers such as Bramley’s, and mouth-puckering crab apples (usually wildings, feral domestic varieties, rather than wild apples). However, there are also ‘true’ cider apples.

The types of apple used for West Country and French ciders are generally high-tannin bittersweets or bittersharps, as opposed to low-tannin sweets and sharps. Growers often hedge their bets with a range of bittersweet varieties and use sharps to balance out the acidity. Sharps are often low in sugar and are used with sweets, which add a characteristic apple flavour and aroma. However, some sharps such as Brown’s Apple and Fair Maid of Devon combine high acid and good cider flavour.

Vintage-quality apples

Vintage quality apples, which are generally high in tannin, have more complex and interesting flavours than ‘bulk’ apples. A few vintage quality cider cultivars such as the crisp Kingston Black or the fruity Stoke Red can produce really good single varietal ciders but most ciders are blends. It is rare for one type of apple to have the ‘perfect’ balance of sweetness, acidity, tannin and aromatics.

Kingston Black is an old bittersharp Somerset variety regarded as the ‘perfect cider apple’. About 80% of an apple is water soluble, as juice. Kingston Black’s contains proportions of sugar, malic acid, tannin, starch, pectin and amino nitrogen that are almost ideal. But it’s unusual to find Kingston Black grown commercially because the tree does not produce a high yield.

There are around 100 apple cultivars in cultivation in Britain. About 15 are in modern intensive orchards with dwarf trees planted close together so they can be harvested by machine while craft cider orchards tend to towards the older ‘standard’ layout with taller trees farther apart. A traditional orchard might have 30 standard trees per acre with sheep or cattle grazing between them but an intensive orchard could have 300 bush trees per acre and certainly no livestock.

Factory versus farmhouse

Most of the modern English cider you will encounter is light in flavour and the product of chaptilisation. This is a way of fortifying cider, usually using glucose syrup, to give you a cider with a higher alcohol content, which is then be ‘cut’ with water. This gives a finished cider with a juice equivalent of between 35% and 50%. In the UK, the minimum legal juice content is 35%. Bulk cider-makers have been making these light ‘glucose ciders’ since the 1970s. But more recently companies such as Aspall and Henneys have made a commercial success of full-juice ciders.

About half of the apples grown in this country go to make cider. Craft cider-makers press in the autumn, ferment the cider of the winter and cask or bottle it in the spring. As the trees blossom, the cider starts to ‘work’ and becomes less harsh. There’s a belief that the cider and the trees are in sympathy. The end product might be consumed in the summer or up to five years later.

Time is the other ingredient

Factory cider is made all year round, much like beer. Typically, mainstream cider-producers work a two or three-week cycle. To keep production going, the industry uses apple juice concentrates. These are made by vacuuming the water out of apple pulp to create a syrup that can be stored for months or years without fermenting. English cider apple pulp is often bulked out with imported dessert apple pulp form countries such as China.

With factory cider, they ferment sugar (the juice, concrete and added sugars) and add nutrients such as ammonium phosphate and thiamine to speed up the fermentation. While traditional, pure juice ciders can take weeks or months to ferment, factory cider can be completely fermented to 12% alcohol in as little as a week,with the judicious use of sulphates and malolactic acid.

Commercial-strength cider

The high alcohol ‘base ciders’ produced from different apples are blended and diluted to commercial strength (3.5%-8.5%abv) before the addition of artificial sweeteners and preservatives, and carbonisation. The cider is then filtered and, usually, pasteurised and canned, bottled or put into pressure-dispense kegs. Big brand ‘cloudy ciders’ are often just clear, finished ciders with juice added back into them.

Naturally conditioned ciders, usually sold in kegs or plastic barrels, are made from fully fermented dry cider that has sugar and yeast added to it to start it slowly fermenting again. Until the middle of the 20th-century bottled cider was like this and it threw a slight sediment and occasionally even exploded so this way of doing things was replaced by forced carbonisation and pasteurisation.

Yeast and fermentation

Yeast used for cider and perry may be either ‘natural’ (the yeast on the fruit and/or the milling and pressing equipment) or cultured yeast. Wild yeasts act in succession, one giving way to the next. This gives the cider character but the fermentation itself is slower than it would be using a single strain of cultured yeast, which also gives more predictable results. English-style ciders commonly go through malolactic fermentation (MLF) which produces desirable spicy or leathery and farmyard or old-horse characters. MLF lowers the total acidity of the cider and rounds out the flavours.

Malic acid is the principal acid in apple. In technical terms it is decarboxylated by lactic acid bacteria. This results in a fall in acidity levels of up to half and the cider becoming slightly carbonated, but some malolactic bacteria can also cause ropiness, where the cider turns oily or mousiness which is when it smells like a mouse cage. They are both controlled by keeping the pH down, racking off the lees and adding sulphur dioxide for storage.

Uncontrolled wild yeast fermentations can have very unpredictable results but cider-makers have long used sulphur-dioxide to control mould, bacteria and undesirable yeasts with methods including sulphur candles. Sulphites can mop up any free oxygen introduced during bottling, reducing oxidation; you’ll hear cider-makers say ‘air is the enemy of cider’. If the cider is to be pasteurised it stops the cider tasting ‘cooked’ due to the interaction of amino acids and sugars. If they are over-used, however, it gives the finished cider a ‘burning match’ character, regarded as a serious fault. Likewise sorbate may be added at the bottling stage to stabilise the cider but excessive use of results in a nasty ‘geranium’ note.