Remarkably, given the extensive scientific literature on bread-making, there is very little recorded research on crumpet-making. If you’re not familiar with the crumpet, here is an introduction from one of the few formal crumpet studies, performed by Professor Pyle of Reading University, UK, c. 2005.
“Crumpets are, it seems, a particularly British product. They are made from a dilute fermented batter which is baked rapidly (in around 3 min) on a hot plate, typically at 200–230 °C. Their structure is intriguing with its characteristic predominantly vertical columnar porous structure, not unlike some volcanic vesicular pumices or controlled porosity metal foams (Shridar et al. 1995). This structure is also essential to eating quality, with its capacity to soak up melted butter or soft cheese.”
“ […] whilst the voidage fraction remains approximately constant, there is a significant increase in the mean diameter of the vertical pores over the crumpet height. Bubble nuclei and the release of carbon dioxide from the heated batter are crucial for pore development. Surprisingly, the internal structure develops very rapidly although it needs 3–4 min to completely form the porous structure.
See: Crumpet Structures: Experimental and Modelling Studies Trans IChemE, Part C, Food and Bioproducts Processing, 2005, 83(C2): 81–88.
Further reading : Mathematical Modelling of Crumpet Formation by Peter Sadd, Page 403, Chapter 38, ‘Bubbles in Food 2, Novelty Health and Luxury’ 2008