Ingenious ideas please for milk cooling!!

[Pooh]

Hi there

As I only wish to hold 300-500litres of cool milk at a time, I am having great difficulty sourcing a 500 litre milk vat. Most are around 1700L upwards. I prefer something simpler than buckets in a fridge 

Any cool ideas gratefully received!

Thanks

[coffee joe]

300-500 liters is about 100+ gals. Where are you located? Is the milk bulk or in jugs?