To make flavored olive oil our friend Tony Pennisi at Big Paw Grub uses dried wild herbs. He says that the intensity of the flavor varies with the season, whether the herbs are wild or domestic, how the local growing conditions have been, etc. etc. It takes a lot of trial and error. Its more art than science and the people who are good at it are reluctant to share their trade secrets. The oil will pick up the flavor fairly quickly, in the first few weeks, and then slowly intensify. Its OK to leave the herbs in for a long time, eventually all the flavor leaves the herbs and the oil flavor stabilizes. Most oil sellers keep it simple and use one herb at a time. I have seen smoke flavoring added to an herb or peppers added to any one of the herbs. When mixing herbs, think salad dressing. Look at some recipes for dressing and substitute the dried herbs for any fresh herbs called for in the recipe. A dipping blend is like an Italian dressing with much more oil than vinegar.

Flavored olive oils and dressings make great gifts but watch out; there are safe and unsafe ways to make flavored olive oil.  The unsafe way is to put anything in the oil that contains water.  That would include garlic, lemon peel, fresh peppers, fresh herbs and spices.  The oil will not support bacterial growth but the water containing herbs will.  Botulism bacteria can grow in this type of environment. There are several ways to get around this

1. Mix all the ingredients, refrigerate them and use them within a week

• Add whole cloves of garlic, lemon peel, fresh or dried peppers, ginger, rosemary sprigs, etc.
• Use a recipe for Italian salad dressing but cut down on the vinegar or lemon juice
• Anchovy Caper dipper:
  Here is our favorite dipper.  It is also used throughout Italy as a sauce on main courses:
  Rinse the salt from 2-4 anchovy fillets depending on size; dry them and cut them into small pieces
  Wash and drain 2 tablespoons of salt cured or capers in brine.
  In a small casserole warm up 1/2 cup extra virgin olive oil; add the anchovies and the capers and cook, mixing constantly, until you obtain a mixture that is homogenous and fluid.

Here's some recipes from Carapelli:

2. Preserve the added ingredients:

Maybe you have seen garlic or herbs mixed with olive oil.  The way it is done commercially is to first preserve the water-containing garlic, herb, etc.  with a strong brine or vinegar solution, then put it in the olive oil.  The vinegar solutions used commercially are up to 4 times stronger than the vinegars you find in the supermarket. You can find them at commercial food supply outlets. Many of the herb mixes have both salt and vinegar which both prevent bacterial growth.  You could use one of the olive pickling solutions listed under curing green olives

3.  Dry the herbs to remove all water, leaving the essential oils:

This can be done with a food dehydrator or just by leaving in the sun.  Then add the spices and herbs to the olive oil.  Whole sprigs of thyme, rosemary, dried peppers, dried mushrooms, etc. can decorate the inside of the bottle this way. 

4.  Press the olives with the spices

Putting lemon, garlic, etc. in the olive press with the olives is the safest way to flavor olive oil.  You must have your own olive press (See First Press), or take it to a commercial press.  The oils from the added ingredients mingle with the olive oil and the watery part of the spices are removed along with the olive water. 

You could mix a small amount of oil with the fresh ingredients, let the flavors mingle, then decant the oil off leaving the herbs and any water behind.  Mix this flavored oil with a larger amount of oil. You could add essential spice oils to the olive oil to achieve the same effect. 

Check out our bottle selection for home cooks who want beautiful containers for their gift oil,  dressing or vinegar.   We also sell bulk oil for your private labeling