Origin of the Spanish expression "la gente de la manteca" according to Brenan

  -Retrato original María José González-

In the ninenteenth century the wealthy families of Malaga used to import barrels of salted butter from Hamburg, and on that account they became known as la "gente de la manteca" or "the butter folk". It was a luxury that set a stamp on one´s social position, like having a car today. Butter was unkown. "Manteca" meant either lard or rancid dripping worked up with garlic and eaten by workmen in the coast towns with bread. This is explained by the fact that Spanish people had no milch cows. Even in the north of Spain there are said to have been none till the Flemish influence at the time of Charles V brought them in, and it is only in recent years that they have been kept in Anadalusia (Brenan, 1963).

Bibliographic source 
Brenan, G. (1963). South from Granada. London: Penguin Books.
https://www.penguin.co.uk/books/15567/south-from-granada/