Even thirty years ago, flour could usually only be found in three kinds – self-raising, plain and strong bread flour. If you wanted other flours, you had to search them out in health food shops and pay a small fortune for them.
Nowadays, there are so many different types of flour from yucca flour to spelt flour, that we are spoilt for choice. One thing is true of all flours though – they don’t keep forever. You need to store your flour properly and be aware of how long you’ve had it for to enjoy it at its best.
Self-Raising and Plain Flour
These flours are refined, so the flour contains less oil. As it’s the oil in flour that goes rancid, these refined flours have a longer shelf life – one to two years if they are kept in a cool, dry place.
White bread flour is refined, so again, if it’s stored in a cool, dry place it will last for one to two years.
Cake flour is also refined, and if it’s stored in an airtight container like a plastic Ziplock bag, it should last up to a year.
Corn flour is a whole-grain flour, so it contains oil. That means it won’t stay fresh as long as refined flours. Put it in an airtight container in a cool, dark place and it will stay fresh for nine to 12 months.
Nut flours that are made from hazelnuts, almonds, etc. contain quite a lot of oils. Nut flours are best kept in the fridge or freezer. In the fridge they will keep for six months, in the freezer for 12.
This flour is made from white potatoes that have been dried and ground into flour. It is high in starch, but doesn’t contain much oil. It will keep for six to eight months in a cool, dry place.
Rice flour is gluten-free, and is a popular ingredient in baked goods. It stays fresh for six to eight months in a cool, dry place.
Whole Grain Flours
Whole grain flours are unrefined and rich in nutrients, largely due to the amount of oil they contain. Oil that is exposed to the air begins to degrade and go rancid (think of butter left uncovered out of the fridge).
The best way to avoid this is to store your whole wheat flour in the freezer, where it can last up to six months when frozen in an airtight container. In a fridge it will last up to four months in a container.
How Can You Tell if Flour Has Gone Bad?
If it smells strange, that’s the most reliable indication that flour has gone off. It may change colour too, but rancid flour smells sour and should be thrown away.