Both hamster mixes and pellets provide your hamster with the basic nutrition it needs, and they should therefore form the main part of your hamster’s diet. They can be stored safely for long periods if kept in dry conditions as they do not perish quickly.
You can buy dried food mixes from most pet stores that are made especially to meet the dietary requirements of hamsters. These contain foods such as barley, oats, seeds and maize, while some include pellets, but you should ideally choose a good quality loose mix that also contains dried fruit and vegetables.
Alternatively, you can buy hamster pellets from some stores. These again meet your hamster’s nutritional needs, but offer a lack of variety and so may be refused, particularly if the hamster is used to being fed a mix.
Although mixes and pellets both offer a balanced diet, it is quite possible that your hamster will be picky and leave its least favorite bits if fed with a mix. You can discourage this by waiting for your hamster to empty its bowl before adding more mix. However, it can be a good idea to instead try to get your hamster used to a mainly pelleted diet if possible, preferably from a young age. You can add variety to this by sprinkling in a small amount of mix.
If you cannot get your hamster to eat pellets or eat all parts of its mix, then you may need to add vitamin and mineral supplements to its diet in the form of treats, chews or liquids. These should only be given in moderation and after consulting your veterinarian.
Treats can also be given occasionally to supplement your hamster’s diet and add variety, even if it regularly finishes its mix or pellets.