score:9
I would suggest a method as simple as any. Freeze it before you leave, put it in your check-in luggage and as soon as you reach the other side, put it in the freezer.
I have done this many times with products which require refrigeration (can be milk based as well) and everything remains okay after the flight.
If you wish to be extra careful or if the product will lose texture after refrigeration, try ice packs instead. They are also quite effective and also keep cold for longer, but unfortunately they also count as additional weight.
Upvote:3
Dry ice (CO2) is a better alternative to regular ice. Doesn't leak, much colder, lighter... Freezing is not all that effective if the item has a low water content, like some cheeses.
Check with the airline, but in general dry ice is considered a "mildly hazardous" item - pack it properly in a vented container, no more than X kilograms and it's good to go.
In Canada dry ice up to 2.5kg is accepted as carry-on.