Marais grew up on the farm Wonderfontein close to Robertson, Cape Colony.
Warren, a director of KWV encouraged him in 1935 to produce and market brandy.
His brands has won awards and it's ranked as a brandy in South Africa and the world.
According to Major C.R Wolhuter, he and Kosie were the only two residents of Robertson, South Africa that were members of the Society to Promote Science.
His theory was that tools made of stone that he found in the soil were older than the San people.
He and Abbé Breuil took a trip to South West Africa and Bechuanaland.
[17] Kosie Marais and his family were members of the South African Party.
Under the leadership of Adolph Malan (Sailor), he was part of old soldiers who formed on 30 June 1951, in Johannesburg, South Africa, the Torch Commando to pressure the government to stop the racial policy.
The United Party ask him to stand for election in George, Western Cape, South Africa in 1948 against P.W.
[18] [19] He married Joyce le Roux from Franschhoek, South Africa in 1926.