In 1933 the Ochoas returned to Madrid where he began to study glycolysis in heart muscle.
Within two years, he was offered the directorship of the Physiology Section in a newly created Institute for Medical Research at the University of Madrid Medical School.
Unfortunately the appointment was made just as the Spanish Civil War erupted.
Ochoa decided that trying to perform research in such an environment would destroy forever his "chances of becoming a scientist."
Thus, "after much thought, my wife and I decided to leave Spain."
In September 1936 Severo and Carmen began what he later called the "wander years" as they traveled from Spain to Germany, to England, and ultimately to the United States within a span of four years.

Ochoa left Spain and returned to Meyerhof's Kaiser Wilhelm Institute for Biology now relocated in Heidelberg, where Ochoa found a profoundly changed research focus.
During his 1930 visit the laboratory work was "classical physiology," which Ochoa described as "one could see muscles twitching everywhere".
By 1936 Meyerhof's laboratory had become one of the world's foremost biochemical facilities focused on processes such as glycolysis and fermentation.
Rather than studying muscles "twitch," the lab was now purifying and characterizing the enzymes involved in muscle action but were involved in yeast fermentation.

From then until 1938, he held many positions and worked with many people at many places.
For example, Otto Meyerhof appointed him Guest Research Assistant at the Kaiser Wilhelm Institute for Medical Research in Heidelberg for one year.
From 1938 until 1941 he was Demonstrator and Nuffield Research Assistant at the University of Oxford.
In 1933 the Ochoas returned to Madrid where he began to study glycolysis in heart muscle. Within two years, he was offered the directorship of the Physiology Section in a newly created Institute for Medical Research at the University of Madrid Medical School. Unfortunately the appointment was made just as the Spanish Civil War erupted. Ochoa decided that trying to perform research in such an environment would destroy forever his "chances of becoming a scientist." Thus, "after much thought, my wife and I decided to leave Spain." In September 1936 Severo and Carmen began what he later called the "wander years" as they traveled from Spain to Germany, to England, and ultimately to the United States within a span of four years.
Ochoa left Spain and returned to Meyerhof's Kaiser Wilhelm Institute for Biology now relocated in Heidelberg, where Ochoa found a profoundly changed research focus. During his 1930 visit the laboratory work was "classical physiology," which Ochoa described as "one could see muscles twitching everywhere". By 1936 Meyerhof's laboratory had become one of the world's foremost biochemical facilities focused on processes such as glycolysis and fermentation. Rather than studying muscles "twitch," the lab was now purifying and characterizing the enzymes involved in muscle action but were involved in yeast fermentation.
From then until 1938, he held many positions and worked with many people at many places. For example, Otto Meyerhof appointed him Guest Research Assistant at the Kaiser Wilhelm Institute for Medical Research in Heidelberg for one year. From 1938 until 1941 he was Demonstrator and Nuffield Research Assistant at the University of Oxford.
Severo Ochoa