They over spiked them, so the flavours were unmistakable. Phenol was obvious and lactic, diacetyl was sickening and light strike was easy enough to recognise. DMS was very unsual. At the level they spiked for our untrained palates it stank of cabbage left to fester in the plug of your kitchen sink. Trans 2 nonenal was there too and it smelled very strongly of wet cardboard and I'm fairly sure it is 'that flavour' we've had problems with, but it was so strong it was hard to tell.