Activate the heat — water first, not oil
Combine 3g mustard MR408 and 3g radish with 5–8ml room-temperature water and allow to sit for 60–90 seconds. Myrosinase is a water-soluble enzyme — it needs an aqueous environment to convert glucosinolates into isothiocyanates (the heat molecules). Oil alone cannot trigger this reaction. Do not add any acid at this stage — acid stops the reaction immediately.