This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
I had a great garlic harvest this year and would like to perserve some
garlic for longer than the dried garlic usually lasts. I have heard
about perserving whole or diced peeled garlic cloves in olive oil but
can't find much info about this. Can anyone help???
Don't do it.
Here's a bit of information that I copied a few years ago from a now
defunct food safety site:
Regardless of its flavor potency, garlic is a low-acid vegetable. The pH
of a clove of garlic typically ranges from 5.3 to 6.3. As with all
low-acid vegetables, garlic will support the growth and subsequent toxin
production of the bacterium Clostridium botulinum when given the right
conditions. These conditions include improper home canning and improper
preparation and storage of fresh herb and garlic-in-oil mixtures.
Moisture, room temperature, lack of oxygen, and low-acid conditions all
favor the growth of Clostridium botulinum. When growing, this bacterium
produces an extremely potent toxin that causes the illness botulism. If
untreated, death can result within a few days of consuming the toxic
STORING GARLIC IN OIL
Extreme care must be taken when preparing flavored oils with garlic or
when storing garlic in oil. Peeled garlic cloves may be submerged in oil
and stored in the freezer for several months. Do not store garlic in oil
at room temperature. Garlic-in-oil mixtures stored at room temperature
provide perfect conditions for producing botulism toxin (low acidity, no
free oxygen in the oil, and warm temperatures). The same hazard exists
for roasted garlic stored in oil. At least three outbreaks of botulism
associated with garlic-in-oil mixtures have been reported in North
From: Ross Reid