Routine tests used historically by the food industry worldwide for detection and enumeration of the spores of aerobic spore-forming bacteria are based on a standard approach: heat-treat the sample to kill vegetative bacterial cells and induce spore germination; plate sample dilutions in agar; incubate the plates and count the mesophilic or thermophilic (depending on the incubation conditions) colony-forming units, which are taken to represent spore numbers. There exist many variations on this theme, with over 60 different aerobic spore test methods known to be used in the Australian dairy industry. Understanding how such differences affect the results might be important where different spore tests are being harmonised, or where disputes arise about products meeting customer spore specifications. A panel of 206 aerobic spore-former isolates was obtained from milk, cheese and milk powder samples. All isolates were identified to genus or species level via partial sequencing of the 16S rRNA gene. The majority of isolates were Bacillus licheniformis, Anoxybacillus flavithermus, Geobacillus spp., B. subtilis, B. pumilus and Aneurinibacillus thermoaerophilus. Two key parameters affecting spore test efficacy were assessed: the choice of microbiological plating medium (Starch Nutrient Agar, Dextrose Tryptone Agar, Tryptone-Glucose Yeast Extract Agar and Plate Count Agar) and spore test heat treatment conditions (80, 100 and 106 ⁰C for 10 and 30 min). Results showed that SNA was the superior plating medium in all cases, yielding significantly higher spore counts. Spore test heat treatment had a major impact on observed counts that was species dependent. Germination was induced at 80°C for all isolates, with no improvement in numbers seen at 100°C for the thermophilic species. The results imply that 80°C/10 min heat treatment and growth on SNA has potential as a broadly-applicable spore screening test, giving higher cfu/ml recovery than the other methods evaluated.