Well, for a while I thought it is great to store garlic cloves in oil in a nice jar. The basic rule was not keeping them like that longer than a week or and always refrigerating but still according to the Food Standards Agency home made garlic in oil jars may do harm to your health
Here FDA says:
“Lots of different types of flavoured oil are available in the shops, containing garlic, peppercorns, chilli and various herbs including rosemary, oregano and bay leaves, and these often have a long shelf life. But it’s not a good idea to make flavoured oils at home unless you are going to use them immediately.
This is because plants, including herbs and spices, can carry spores produced by bacteria. Occasionally, they could carry spores of a type of bacteria called Clostridium botulinum, which can cause botulism. This is a very unpleasant disease, which is rare in the UK, but can be fatal.
Clostridium botulinum multiplies in places without any oxygen, so if there are spores on plants such as herbs and garlic, putting them in oil can create the right conditions for the bacteria to multiply, particularly if the herbs are fresh or wet.
Companies that produce flavoured oils and foods preserved in oil are expected to take Clostridium botulinum into account and formulate their products to make sure that this type of bacteria doesn’t multiply.
Even though recipes for flavoured oils can be found in cookery books, magazines and websites, these might not have considered the risk of botulism. So if you would like to make your own flavoured oil, the safest option is to make a small quantity and use it on the day you have made it. If you have some oil left over, put it in the fridge straight away and use it within a week. Some oils can go cloudy or become solid in the fridge, but if this happens don’t be tempted to leave it at room temperature, because this might not be safe.”
So I still adore garlic and I adore spices and olive oil together but it is better to consume any mixture you prepare as quick as possible and not to make lots as it will go to the food waste which none of us like I guess.