I know using fresh herbs to infuse oil can be dangerous as the oil might become a breeding ground for botulism. I was wondering, if I first rinse my herbs (or peppers for that matter) and then dry them for several weeks/months, would it be safe to make an infused oil with these dried herbs compared to fresh ones?
realted: cooking.stackexchange.com/a/33635/3649.– MandoMandoMay 17, 2013 at 14:45
On a side note, dried tomatoes are apparently too acidic for botulism to grown in: Vegetables and herbs to be packed in oil without treatment with vinegar should be dried almost to crispness. Tomatoes, including sun-dried tomatoes, are a special case. The pH of fresh tomatoes is normally just below 4.6. When the tomatoes are dried, the natural acid components are concentrated and the pH is reduced. It will often be close to 4.0 in the dry product and therefore the risk of food poisoning is eliminated.– CerberusMay 17, 2013 at 15:35
No such safeguard exists with other vegetables, however, and these must be either acidified or properly dried before being covered with oil. This includes small quantities of garlic or herbs which may be added to other preserved vegetables as flavourings. — csiro.au/resources/preservation-in-oil-vinegar– CerberusMay 17, 2013 at 15:35
Per the University of Ohio Extension, yes, it does reduce the risk (emphasis added):
Flavored oils also can be a concern if not prepared correctly. When herbs, garlic, or tomatoes are placed in oils, the botulism spores on the plant material can start to produce the toxin in this anaerobic mixture. To be safe, keep these flavored oils refrigerated and make only the amount of herbal oils and butters that will be used in a few days. Using dried herbs and vegetables will also reduce the risk.
Still, reduce is not eliminate. The guidelines to not can or hold the oil for long term continue to apply.
2What is considered a long time? Like days or weeks? May 17, 2013 at 13:59