The honest answer is that it depends on the food, and on how you store it. But the pattern is consistent enough to be useful, so here is what to expect.
Why air is the problem
Three things spoil dry pantry food: oxygen, moisture and light. Oxygen is the big one. It turns the natural oils in nuts, coffee and wholegrains rancid, which is that flat cardboard taste you get from a bag of coffee that has been open a fortnight. Moisture is what makes crackers go soft and flour clump.
Pulling the air out of a sealed glass jar removes most of the oxygen and locks moisture out. That is the whole mechanism. Nothing exotic.
Rough shelf life, sealed versus not
These are general guides for a cool, dark, dry cupboard. Your kitchen, your climate and the state of the food when you sealed it all move these numbers around, so treat them as a starting point rather than a promise.
| Food | In the packet or a normal container | Vacuum sealed in a jar |
|---|---|---|
| Whole coffee beans | 2 to 4 weeks before flavour drops off | Several months |
| Ground coffee | 1 to 2 weeks | 1 to 2 months |
| Nuts and seeds | 1 to 3 months before they turn | 6 months or more |
| Plain flour | 6 to 8 months | 1 to 2 years |
| Wholemeal flour | 2 to 3 months, the bran goes rancid | 6 to 12 months |
| White rice | Years already | Longer again, and safe from pantry moths |
| Brown rice | 3 to 6 months | Around a year |
| Dried pasta | 1 to 2 years | Longer, and it stays brittle rather than soft |
| Rolled oats | 3 to 6 months | Around a year |
| Dried herbs and spices | 6 to 12 months before they fade | 2 years or more |
| Crackers, biscuits, cereal | Days to weeks once opened | Months, still crisp |
| Dried fruit | 1 to 3 months | 6 to 12 months |
The pantry moth bonus
Nobody buys a jar sealer for this and everybody ends up grateful for it. A properly sealed glass jar is not something pantry moths, weevils or ants can get into. If you have ever had to throw out a whole shelf, that alone pays for itself.
What vacuum sealing does not do
This matters, so we will be blunt about it.
Vacuum sealing a jar is not canning. It removes air, it does not heat-process anything, and it does not make fresh or low-acid food shelf stable at room temperature. If something needed the fridge before you sealed it, it still needs the fridge.
It also will not rescue food that has already turned. Seal it fresh and you keep it fresh. Seal it stale and you have a stale jar.
And FoodVault is built for dry goods rather than liquids.
Getting the most out of it
Fill jars close to the top, leaving about 2cm of headroom. Less empty space means less air to begin with. Keep jars out of direct sunlight, because light degrades oils and spices even in a sealed jar. And label them, so the jar of something beige at the back of the cupboard does not become a mystery.
If you want the full walkthrough, start with how to use your jar sealer.