Posted to the British Interactives Group chat-list:
“Interesting stuff, Marmite. I recently started a large new jar, and apart from the seasonal shock at how damned expensive the stuff is, I find myself musing on the yeasty material’s viscosity. As one does.
Marmite-haters will, tragically, not be aware, but it’s an extremely stringy substance, doing near-everything it can to land somewhere between the jar and one’s toast, with a secondary goal of clogging the jar-top thread. By the end of a jar it’s not unusual to find more Marmite clinging to the thread (and the lid) than to the sidewalls. However, the flow rate of the material is exceptionally low; even after several months, the Marmite surface within the jar will not be absolutely level. High crests and troughs left by the gouging actions of a table knife will be smoothed, but not completely flattened.
The possibility occurs that Marmite is thixotropic, or possibly that it may be used to illuminate the distinction between viscosity and ductility. I confess, however, that material properties and the underlying mechanisms are not my strong suit.
I then find myself pondering whether it might be possible to measure Marmite’s surface tension. Indeed, could one blow Marmite bubbles? Alternatively, could one produce an analogue of Kelvin’s tar drop experiment, only with a rather more ‘interactive’ period between drips?”
Posted by, yes, me.