Bitter orange. Fruit of the bitter orange tree. The rind of bitter oranges is full of a sour, bitter, aromatic, healing and comforting essential oil, composed of very subtle notes; the rind burns when put to a flame, and inside there are small, transparent juice vesicles. The juice of bitter oranges imparts, by its acidity, a beautiful purple color to violet jam and to blue paper; it is also contained in specific, enclosed membranes inside the fruit.

The essential oil of bitter oranges , commonly named Neroli oil , has the same properties as lemon.

To make orange blossom water, the bitter orange is distilled in a double boiler, with the bitter orange completely crushed. By this technique, the acidic part becomes infused with the essential oil and the oil gains properties that improve heart health, without becoming heating up.

Everyone knows that lemonade is a beverage that one makes with water, sugar and bitter oranges . This artificial liquor had the honor of giving its name to a community in Paris, who at first were only resellers, but were elevated to guild status in 1678.

It is important to not confuse the simple lemonade made from water of bitter oranges and sugar with that which is commonly consumed in large quantities on the islands of America, called punch ; the latter is made of wine from the Canary Islands, bitter orange juice, sugar, cinnamon, cloves, and essence of amber; it’s a delicious drink. 

The juice of the bitter orange is added to many purgatives, to make them less unpleasant and more effective in their use. For example, one can collect a dram [1] of leaves from the Asian Senna tree, three ounces of manna, a grain [2] of vegetable salt, and a half-grain of coriander, two handfuls of burnet leaves, and bitter orange slices. Pour two pintes  [3] of boiling water over the drugs, let it soak overnight, and then strain it. Add a few drops of essential oil from a lemon rind and divide this laxative herb tea into four doses, two of which one drinks over two hours.

To make a gargling solution for the gums for those with scurvy, combine spirit of scurvy-grass and spirit of wine, one ounce of each, two ounces of bitter orange juice, and four ounces of watercress water. However, it is simple to combine and multiply indefinitely, depending on the case, these types of remedies.

Bitter oranges taste more acidic than oranges and lemons; this acidity is likely the reason that they are more refreshing. However, everything that we have said of the lemon, its properties, uses and preparations, applies equally to fruit of the bitter orange tree.

The fruit is abundant in the East and West Indies. Specifically, in Tonkin, there are two types of bitter oranges , some yellow, the others green; but all so sour that it is not possible to eat them without having an upset stomach. These fruits, however, are not useless for those from Tonkin, or for other people from the East Indies. Not only do they use it, similarly to how we use aqua fortis , for cleaning copper, brass and other metals when they want to prepare them for gilding, but also for dyeing, and especially for dyeing silk.

Another usage that they have for bitter oranges is for bleaching linens; They put them in the wash, especially fine linens, and this gives them a remarkable white color and brightness, as can be seen primarily in all the Mughal’s cottons, which are only bleached with the juice of these types of bitter oranges .

Our dyers also use bitter orange juice in Europe, to change various colors and make them more set. The words that are written using this juice appear on paper when brought close to fire. It is one type of invisible ink; but there are others that are much more interesting. See Invisible Ink.

On the subject of bitter oranges , one can consult all the authors cited in the article Lemon tree and, among others, Ferrarius, who has done the best work.

1. One dram is a unit of weight used by apothecaries and equal to 1/8 ounce.

2. A grain was equivalent to a dram.

3. A pinte is a unit of volume, and is equivalent to approximately two U.S. pints, or 952 milliliters.