bottling with a filter tank and mould

[thenewguy]

over the past couple of months i have noticed the odd bottle of syrup with a little mould growing on top of the syrup. after drawing syrup off the evaporator, filtering it into a 16x16 finisher ( through flat filter). bringing it upto the proper density with the hydrometer, i draw out of the finishing pan, run the syrup through a cone filter into a round 5gallon filter tank/bottler. im now questioning why im getting moulding, im thinking possibility of the the round 5gallon filter tank not staying hot enough. generally every draw off the finisher is around 8 litres (2 gallons). i double check the brix and am always bang on. when im bottling the syrup you generally can't even touch the bottle because it is so hot, then of course i tilt the bottle upside down to sterile the cap. Does anyone else bottle with round 5 gallon filter tanks?? anyone have a way of keeping them warm over the entire bottling process? i would think the syrup would stay hot enough after being drawn out of the finishing pan, through a cone filter and right into the tank, from the time i draw to start bottling would maybe be 1.5- 2 mins. generally store syrup in a box in a cool area.

[DrTimPerkins]

Syrup needs to go in the bottle at 180-190 deg F. That means that the entire container+syrup needs to achieve this temperature before you put the cap on. If it is glass, you may need to warm the glass (takes a fair amount to heat up the glass). My guess is that your first couple of jugs might cool off too much going through the cone filter, and likewise, the syrup you can up at the end might be cooling off to much. If you heat any higher than 190 deg F, you can form niter in the container.

[gmcooper]

I used to have a round tank although bigger. I always had to use gas burner for heat to get back up to bottling temp and keep it there. With the 5 gallon size you have a lot of surface (tank side walls) Per gallon of syrup to conduct heat and cool the syrup. I didn't have to keep the heat cranked up but kept flame just enough to maintain 185 or close to it.