Food safety when keeping chocolate or compound melted
Posted in: Chocolate Education
Loads of documentation out there on the role of water activity and food safety - do a google search for water activity chart, for example, and you'll get a handy printable wallet card you can give your friendly food inspector. water activity (Aw) isn't a measure of how much water is present - it's a measure of how much water is *available*. For chocolate/compounds, they're essentially the same thing. Your typical coating will have an Aw of approx 0.2-0.3 - which is 2-3x lower than is required to support the most basic forms of microbioogical growth (the minimum Aw required to support growth is slightly above 0.6 Aw)
If you're talking something like milk, sauces, soups, etc - things that are mostly water - 100F is where mesophilic bacteria love to play - likely your food inspector is looking at it through the lens of the buffet line at your local old country buffet - where if you leave almost anything there at 100F for very long, you're likely to get very sick. since there's only tenth's of a percent of water in compound, and any of the water that's there isn't available to support growth anyway (ie it's either in the form of water of crystallization, surface monolayers adsorbed to milk/sugars, etc), there's absolutely zero risk of micro growth. as long as you're not adding anything with moisture into it. Your supplier can give you the exact Aw, moisture content, and ingredient label that you can then give to your inspector to prove there's no risk.
EDITED to note that frequently washing your chocolate melters can actually INCREASE the risk of microbiological contamination. if seems many cases where post washing, equipment has not been dried properly - and that'll lead to problems. certainly not saying you shouldn't be washing your equipment, but many folks overwash or wash improperly and unintentionally increase their risk exposure. Large scale enrobers NEVER get water washed. Water is quite often the enemy in a chocolate plant.