Seven things never to buy in bulk

When you're faced with a fantastic multi-buy deal, or an enormous container offering what appears to be better value than a smaller one, it's easy to get carried away and fill the trolley. However, while buying in bulk is sometimes a brilliant way to save, there are some times when it's a disaster. We reveal seven things you should never by in bulk.

1. Cooking oil
Dietitian Julie Brown says buying oil in bulk is a bad move, because the shelf life is not as long as you think. Typically it'll last around 3-6 months, so if you're getting through huge containers of oil in that time (or more than one container) you may need to consider how much oil you're using in your cooking.

2. Spices
Sitting in your cupboards, they will lose their potency, until after three months they're next to useless. Your best bet is either to buy the smallest pot you can, or buy spices like coriander seed and peppercorns whole and grind your own when you need it.

3. Condiments
Brown points out that if you're getting through giant containers of condiments within their shelf life, then unless you have a huge family, there's a chance you're using too much of them.

4. Fruit and veg
If you're clever about how you use them, then buying multi-buy deals, and large quantities of reduced fruit and veg can pay off. However, if they rot in the fridge before you have time to use them all, then all you're doing is wasting money.

5. Anything that's just 'bigger'
Don't assume that bigger packets are always better value. In some cases there will be an offer on a smaller item, or a pricing anomaly. So before you plump for the family size pack, get your calculator out and make sure you're getting the best possible deal.

6. Treats
Studies have shown that the more we buy of things like chocolate and crisps, the more we eat. It's not a saving if you go for an extra-large packet of biscuits and then eat them twice as quickly as a smaller one.

7. Anything at a warehouse that you haven't price-checked
The big bulk-buying warehouses seem like a cheap way to buy things with long shelf lives - like tins, toilet rolls and shampoo. They are certainly often cheaper than buying for full price at the supermarket - but it's still not the approach that'll get you the lowest price.

If you wait for special offers at the supermarket, and stock up then, you can get these items for as little as half price - vastly undercutting the wholesaler.

But what do you think? Do you buy in bulk? Does it work for you? Let us know in the comments.