Cider apple

Cider apples are specialized cultivars grown specifically for the production of cider.

In the United States, this beverage is often called "hard cider." These apples differ significantly from dessert apples, which are grown for eating, or "cookers," which are used for cooking. Cider apples often possess bitter or dry flavors that make them unpalatable as snacks. However, these specific chemical properties are essential for creating a high-quality fermented beverage. To produce successful cider, the fruit must contain high sugar levels. These sugars encourage fermentation and raise the final alcohol levels. Additionally, tannins are vital because they add depth to the finished cider's flavor profile.

Successful cidermaking relies on a precise balance of sugar, acid, and tannin. Most producers do not rely on a single cultivar to achieve this balance. Instead, they blend juices from multiple apple categories to ensure a consistent quality. For example, sharps provide high acidity, which helps keep the pH below 3.8 to prevent spoilage. Sweets provide the necessary sugar levels for fermentation to reach the proper alcohol content.

Sometimes, makers even use cooking apples, such as the Bramley variety, to add acidity to a blend. This careful mixing allows makers to control the complexity and stability of the final product.

In 1903, Professor B.T.P. Barker established a formal classification system in England. He served as the first director of the Long Ashton Research Station (LARS) in Bristol. His system categorized cider apples into four main types based on tannin and malic acid percentages. The first type is "Sweet" (SW), which has low acid (<0.45% w/v) and low tannin (<0.2% w/v). Examples include the Sweet Alford and Sweet Coppin varieties. Most dessert apples also fall into this category.

The second category is "Sharp" (SH), defined by high acidity (>0.45% w/v) but low tannin (<0.2% w/v). These apples, such as the Crimson King or Tom Putt, can add a "bite" to the cider. The third category is "Bittersweet" (BSW), which features low acid (<0.45% w/v) and high tannin (>0.2% w/v). Many bittersweet cultivars, like Dabinett or Yarlington Mill, have European origins. They were often called "French" or "Norman" in English cider counties. The fourth category is "Bittersharp" (BSH), which contains both high acid (>0.45% w/v) and high tannin (>0.2% w/v).

Because they are naturally unpalatable, bittersharps have historically been called "spitters." Varieties like Kingston Black are particularly suitable for making single-varietal ciders.

Different regions have developed their own unique ways to classify these fruits. The Long Ashton system also used a three-level scale for tannins: "full," "medium," and "mild." For instance, Chisel Jersey is considered a "full bittersweet." In France and Spain, classification systems include an intermediate category. In France, this is called "acidulée," and in Spain, it is "acidulada." These systems categorize apples that are semi-tart and have low tannin content. They continue to use acidity and tannin levels as the primary metrics for sorting varieties.

In the United States, cider apples are grown in four distinct regions. These include the Northeast, Mid-Atlantic, Midwest, and Northwest. Out of the twenty most common cider varieties grown in the U.S., half originate from England. Two varieties come from France, while the rest are American. Because high-tannin cultivars are less readily available in the U.S., many American ciders are made from culled dessert apples. These are generally a mix of sweets and sharps. There is currently no systematic classification for North American cider cultivars, though the U.S. National Plant Germplasm System (NPGS) maintains a database of apple varieties.

Cidermaking involves complex chemical measurements beyond simple flavor. Professionals look at pH, polyphenol composition, and soluble solid concentration, measured in degrees Brix. The Brix level helps quantify the potential alcohol that yeast can ferment. This is important for following tax regulations. In the U.S., hard cider falls into a tax bracket between 0.5% and 8.5% alcohol by volume. If a cider exceeds 17 °Brix, it may be subject to higher taxes as a "cider wine."

Even the foam on a cider is scientifically significant. Hydrophobic polypeptides contribute to the foam's height, stability, and bubble size. These chemical traits help assess the overall quality of the finished beverage.