Teachers' conceptual subject matter knowledge of stoichiometry is a global concern. Such knowledge is contextually dependent, as is the feasibility of attaining particular outcomes during in-service teacher education workshops. In an attempt to understand what is feasible in various contexts, I explore the relationships between South African physical sciences teachers' environments, education, and teaching experience and their possession of, and ease with which they learn, various types of stoichiometry knowledge. This is done through the analysis of the pre- and posttest and biographical survey data obtained from 184 teachers who attended a two-day stoichiometry workshop. The findings suggest that teachers teaching in contexts of poverty, particularly when lacking a B.Sc. degree, show a particularly high preference for algorithmic over conceptual knowledge. The success with which the teachers in the sample learned facts about relationships between concepts during the two-day workshop suggests that such an approach could provide an entry point into currently less feasible conceptual learning. No correlation was found between extent of tertiary chemistry study and stoichiometry subject matter knowledge, even for teachers with a B.Sc. degree. Statistically significantly higher levels of stoichiometry knowledge were found for the following teacher groupings compared to their counterparts: teaching in a school serving a socioeconomically more advantaged community; having over three years' teaching experience; possessing a B.Sc. degree. The suggestions derived for in-service teacher education targets are likely to have relevance in developing countries and in developed countries where considerable socioeconomic differences exist.