Question: I live in Japan and milk is sold only in cartons here. I take milk to the fridge at work. I currently put it in a black plastic bottle with black cover but it stinks like it is off after only a few days. The milk is fine as far as I can tell. I doubt there is food safe plastic bottles here. I carry by bicycle and the bar fridge is small and at times very crowded as it shared so spillage is a great risk. What is the best solution? I use the milk for adding coffee and cocoa- I may have one drink or many drinks- depends on how sleepy I am that day. I buy 1 litre cartons as I am poor but I couldn't drink 1 litre at work in a week even. The main milk is always fine.

Answer: 
The key thing is that you **empty and wash the container regularly** (ideally daily, but at least every few days). If there is a bad smell that is a sign that something is wrong; most likely some milk remained somewhere like a screw top or drops on the lid, which has gone off in some way.

**Any bottle sold for drinking water should be food safe** in terms of its material, so I would be very surprised if you cannot find anything. However, I would try to find a bottle which:

* is **easy to clean** completely, so no complicated closing mechanism or built-in drinking straw.
* will provide reasonable **insulation** while the bottle is out of the fridge, for example a thermos bottle (which uses vacuum in the walls to insulate the contents).

Anything suitable for carrying hot coffee is likely to work well for your needs, in case that's a useful way to search.
**Sterilized shelf stable milk in small cartons.**

[![milk](https://i.stack.imgur.com/3lHUO.png)](https://i.stack.imgur.com/3lHUO.png)

<https://www.morinagamilk.co.jp/english/products/jp/>

Order a bunch and bring the unopened cartons to work. Or ask the store where you shop to start stocking it.