Most people find it helps to make all their days worth of juice in the morning or the night before.
This is absolutely fine as long as you store your juice in some kind or air tight container and keep it in a fridge. You can even freeze the juice the night before. When filling your container with juice, make sure to let the juice overflow slightly as this will ensure that no air can be trapped in between the juice and the cap. If you don’t have enough juice to fill the container, add a little MINERAL or FILTERED water. DO NOT ADD TAP WATER TO A JUICE! It also helps to add a lime or lemon juice to help preserve the juice.
When I’m storing a juice to use at home, I will usually use a glass VOSS bottle and store them in my dark fridge.
When taking my juice outside I will use a aluminium SIGG flask as this doesn’t let any light in. If I’m not going to be able to store the juice in a fridge, I will take a ice pack and keep the flask in a box with that to keep it cool.
So any kind of glass container or aluminium flask will do, as long as they are screw tight at the top. If you have to then you can use plastic but I have found, as well as other people, that some juices seem to taste a little off when used in plastic containers.
The amount of time that you can store a juice depends on the juicer that you use. If you are using a centrifugal juicer, I would recommened that you drink your juice within 24 hours. If you are using a masticating juicer, then you can store the juice for up to 72 hours. The reason centrifugal juices go off quicker than masticating is due to oxidation from the heat generated from the spinning blade.
And remember, 500ml of juice is considered the “equivalent” to a meal. So look for containers that are around 500ml.