Hacienda Castañer was established by Spanish immigrant from Sóller, Mallorca Juan Castañer Anglada (1847-1916) who arrived in Puerto Rico in 1861 to work as a field hand at Hacienda San José/Los Rábanos owned by fellow Spaniard and family friend Juan Colom.  He soon learned all the intricacies of cultivating and processing coffee and some two years later became an overseer.  In September 1868 Juan decided to venture on his own, bought an estimated two hundred and fifty cuerdas from Juan Colom, established a small store and began planting coffee.  In  June 1870, in need for help in his thriving business, Juan established the firm Castañer Hnos. when he hired Juan Colom, most likely son of his first employer on the island, and sent for his brother Antonio Castañer Anglada (1851- ) who was still living in Sóller.

During the decade on 1870 Juan acquired several tracts of land sometimes reselling them at a profit, these were often acquired from local farmers in lieu of payment for debt incurred at the store.  A drought that lasted from 1873 to 1874 and Hurricane San Felipe of 1876 that affected Puerto Rico for ten hours, had a devastating effect on the island's agriculture.  Although it affected Castañer Hnos., its effect on small farmers was even greater, resulting in the Castañer's acquisition of a vast number of cuerdas in lieu of payment.  During the decade of 1880 they continued to amass additional land through purchase and foreclosures. 

While Antonio remained running the coffee plantation, processing house and store at Hacienda Castañer, in 1883 Juan moved to Yauco to establish and run a mercantile firm and commercial store to negotiate directly with large coffee exporters in Ponce and Mayagüez.  On May 11, 1886 he married also Majorcan Francisca Vallés Pascual and that year had their only child Maria Castañer Vallés (1886- ).  In 1888, Francisca died en route to Sóller leaving Juan a widower. 

In 1888 Juan brought to work at the mercantile firm in Yauco his son born out of wedlock, Ramón Castañer Velez (1870- ), who although in 1890 got married and established his own plantation in Ciales, by 1897 had returned to work for Castañer Hnos.  In the 1880s , Antonio brought to work for him Majorcans Antonio Joy Joy as accountant in the mercantile firm in Yauco and Antonio Ozonas Frontera, son of his friend Bartolomé Ozonas who would often send him Spanish wines to sell on the island, to help him in the hacienda.  Ozonas Frontera later married his daughter Maria in 1906.

In 1897 Antonio returned to live in Spain and Juan became increasingly concerned about his economic well being due to the political instability in Spain and its war with the US.  Puerto Rico's economy in general was negatively affected; commercial houses defaulted on payments, bank credit was suddenly unavailable and land values declined.  In 1898 Juan returned to Spain not before establishing the firm Scres. de Castañer Hnos. S en C to take over the administration of his personal assets and those of Castañer Hnos.  The members of the new firm were Juan and Antonio Castañer Anglada as limited partners who oversaw the business while living in Mallorca, Juan's son-in-law Antonio Ozonas Frontera, Juan's son Ramón Castañer Velez and Antonio Joy Joy. In the decade of 1900, Majorcans Miguel Alemañy Casasnovas (1883-1970) and Pedro Pons Arbona (1877-1924) also became partners, Pedro as administrator of the plantation.

Scres. de Castañer Hnos. S en C, continued to operate successfully, acquiring additional land.  By 1914 they owned some two thousand four hundred cuerdas of which one thousand five hundred were planted with coffee trees.  WWI had a negative impact on the coffee industry in Puerto Rico as the European market demand for coffee was drastically diminished.  The Great Depression, Hurricane San Felipe of 1928 and Hurricane San Ciprian of 1932 had additional negative effect on the industry basically making it disappear.  

Some of the plantations which comprised Hacienda Castañer were:

In 1928 Sucrs. de Castañer Hnos. SenC ceased to operate mainly due to the damage caused by Hurricane San Felipe.  In the 1930s large tracts of land in Barrio Bartolo were sold to the Government of Puerto Rico who distributed it in parcels to local people.  The firm was legally dissolved in 1938 wen all remaining assets and liabilities were distributed among its members.  Of the assets distributed in 1938, Hacienda La Balear was retained by Antonio Ozonas Frontera, son-in-law of Juan Castañer Anglada, Hacienda Buena Vista was retained by Pedro Pons Arbona and Hacienda Quebrada Bonita by Miguel Alemañy Casasnovas.  

Today the only remain of Hacienda Castañer is the Manor House or "Casa Grande" which is within the populated area or township still today known as Castañer.  The book Castañer: Una Hacienda Cafetalera en Puerto Rico (1868-1930) by Luis Edgardo Diaz Hernandez, PhD has the detailed history of this plantation and its owners.  The video Memoirs of Puerto Rico produced by two family descendants, though partly in the Mallorquín language, is a very detailed and interesting history of the Castañer brothers and Hacienda Castañer.