Jozua Malherbe Joubert received his schooling at the Public School, Montagu, Western Cape, passing the matriculation examination of the University of the Cape of Good Hope in 1909. Continuing his studies at Victoria College, Stellenbosch (from 1918 the University of Stellenbosch) he obtained the Bachelor of Arts (BA) degree in 1912, and subsequently the degree Master of Science (MSc). During 1917 and 1918 he was an assistant in the Department of Chemistry, under Professors B. de St. J. van der Riet*, C.D. van der Merwe* and D.F. du Toit*. During this period he collaborated with Prof van der Merwe in compiling an Introduction to inorganic preparations (1918).
Joubert then went to the United States to conduct his doctoral research at the research laboratory of organic chemistry of the Massachusetts Institute of Technology (MIT). He was awarded the degree Doctor of Philosophy (PhD) in chemistry in 1922, with a thesis on The polymerization of the amylenes. A paper with the same title, based on his doctoral research, was later published in the Journal of the American Chemical Society (1927) under the names of J.F. Norris and Joubert.
After his return to South Africa Joubert was appointed as professor of chemistry at the University of Stellenbosch from 1 January 1940. He held this appointment until his retirement in June 1958. The next year he, in collaboration with G.J.R. Krige and K. Borgin, published a research letter in Nature on "Evidence for a hydrate of cellulose from studies of its surface properties". At that time he was attached to the Chemistry Department of the Institute of Forestry and Wood Technology of the University of Stellenbosch.