How to store flour correctly to keep it fresh

Why good flour deserves better than a paper bag

If you have ever splashed out on a bag of stoneground wholemeal, or hunted down a heritage variety such as spelt, emmer or einkorn, you will know the difference it makes in a loaf. The flavour is nuttier, the crumb more characterful, and there is something quietly satisfying about baking with grain that has a story behind it. All of which makes it a real shame when that flour turns stale, musty or worse before you have had a chance to use it.

Flour is not an inert powder that sits patiently on the shelf forever. White flour will keep reasonably well for months, but wholemeal and heritage flours contain the oily germ of the grain, and that oil is the first thing to go. Once it oxidises, the flour turns rancid, and no amount of proving or shaping will rescue it. Add heat, damp and cupboard pests into the mix and a good bag of flour can be spoiled within weeks. The fix is simple, cheap and takes about ten minutes to set up properly.

Choose containers that actually seal

The paper bag your flour arrives in is designed for the journey home, not for long-term storage. It breathes, it tears, and it offers nothing but an open invitation to pantry moths. Decant your flour as soon as you get it home.

• Clip-top glass jars with a rubber gasket are excellent for smaller quantities and let you see at a glance how much you have left.
• Food-grade plastic tubs with a tight-fitting lid are ideal for larger sacks, particularly the square ones that stack neatly and waste no shelf space.
• Heavy-duty buckets with sealed lids suit anyone buying 10kg or 16kg at a time, which is often the most economical way to buy heritage grain.

Avoid anything that merely folds over or clips loosely. If you can smell the flour through the lid, air is getting in. Glass is easiest to clean and does not hold on to old smells, but a good-quality plastic tub is lighter and less nerve-racking if you are clumsy. Whatever you choose, make sure it is completely dry before it goes anywhere near the flour, and label it with the variety and the date you opened it.

Find the right spot in the kitchen

Cool, dark and dry is the golden rule. A steady temperature somewhere below about 20°C is ideal, and fluctuation is worse than a slightly warmer but consistent spot. Every time the temperature swings, condensation can form inside the container, and moisture is the enemy of good flour.

That rules out the obvious places. Above the oven or beside the hob is far too warm. The windowsill is out, both for the heat and the light. Under the sink is the worst spot in the house, because of the damp. A High Street baker's instinct is to keep stock in a cool back room, and your kitchen should follow the same logic.

• A low, interior cupboard away from appliances is usually the best choice.
• A cool larder or pantry is superb if you are lucky enough to have one.
• A garage or utility room works in winter, but check it does not get damp or overly warm in summer.

Keep the flour off the floor if you can. Not only is it cooler and further from any rising damp, it also makes life much harder for mice and insects.

Watch out for weevils, moths and other unwanted guests

Flour beetles and pantry moths are the bane of many a baking cupboard. They arrive quietly, often inside a bag you have just brought home, and before long you are finding silky threads or tiny beetles in your best spelt. An airtight container is your first line of defence, but a few extra habits help enormously.

• Freeze new flour for 48 hours before decanting it, particularly wholemeal or anything bought from a bulk bin. This kills off any eggs or larvae already present.
• Check the cupboard monthly and wipe down shelves with a vinegar and water solution.
• Never mix old flour with new. If you spot an infestation, throw out everything in the affected container and clean thoroughly before restocking.
• Keep a bay leaf or two in the jar if you like, though airtightness does far more work than folklore.

Rotate your stock like a proper bakery

Home bakers who buy in bulk need a system. The trick professional kitchens use is simple: first in, first out. When a new bag arrives, it goes to the back of the cupboard, and the older flour comes forward to be used first. Write the date on every container with a marker or a piece of masking tape.

As rough guide, white plain and strong bread flours keep for around six to nine months in a cool cupboard, while wholemeal, spelt, rye and other whole grain flours are best used within three to four months for the best flavour. Stoneground flours are often fresher than supermarket ones when you buy them, but they also age faster.

If you bake only occasionally, the freezer is your friend. Flour freezes beautifully in a well-sealed bag or tub, and it will keep for a year or more. Bring it to room temperature before baking, and remember that cold flour absorbs liquid differently, so give your dough a few extra minutes to come together.

Know the signs that flour has gone past its best

Trust your senses. Fresh flour smells sweet and faintly of grain. If it smells of crayons, old walnuts or a damp cellar, it has turned. Wholemeal flour that has clumped, feels tacky or has developed a greyish cast should also go. Flour that tastes bitter, or leaves a slightly soapy sensation on the tongue, is rancid and will taint everything you bake with it.

A quick rub between your fingers tells you a lot. It should feel dry and free-running, not compacted. If you are unsure, bake a small test batch before committing a whole loaf to it. A little care in storage means every bag you open is as good as the day it was milled, and your heritage loaves will taste all the better for it.