Extracto de Malta started life as a 'seafarer's beer'. Seamen calling at Hamburg bought the malt extract then brewed for consumption on high seas due to its high nutritiousness.
That is how it reached the New World, where the inhabitants, especially in the Dominican Republic, took it up enthusiastically and were creating myths around the healthy impacts of the dark, slightly viscous drink.

It was soon and is still regarded there as a tonic, health-giving and stimulating beverage, to be drunk either purely, mixed with condensed milk or as a cocktail with brandy or egg.