A question about a recipe: Mushroom Saute with Greens, Pancetta, and Wild Mushroom-infused Olive Oil

Commercial infused oils are acidified, so they don't have to be refrigerated. I didn't believe that there are any USDA-approved methods for the home cook, and just wrote that on a similar question of brent's. But I'd be glad to see a reference otherwise, if the Ideas in Food or someone else has one.

I notice that all the mushroom infused oils i see on the shelf don't say refrigerate after opening.. How do they do it?

I tested this for the EP review. The porcini infused olive oil is fabulous and would be well worth the minimal effort required fully to dry the porcini, to make it shelf stable. I like the idea of adding some dried herbs, but would use a very light hand with them, at least initially, lest they interfere with the mushroom flavor ;o)

This method would not be the way to go to make infused oils that you want to keep for more than a week in the refrigerator. The biggest issue with oil infusions is botulism. Water in the oil from the hydrated mushrooms can create an environment that allows the bacteria to grow. Instead you can do a warm or cold infusion with dried mushrooms for a more shelf stable product. If you like the caramelized flavor of the roasted mushrooms you can toast the dried mushrooms in a saute pan or moderate oven before adding them to the oil. Dehydration has the benefit of intensifying the flavor of the mushrooms and breaking down their cell structure so that the oil penetrates the mushrooms more easily. A warm infusion will speed up the process, just be careful not to let the oil get too warm because that will destroy the oil's natural flavors. If you're using an extra virgin olive oil we recommend a cold infusion to better preserve its flavor. You can also add some dried herbs, rosemary, thyme, or whatever you like best with your mushrooms to add more flavor to the finished oil. Let the oil infuse for at least a week and up to a month in a cabinet or other cool, dark spot in your pantry before using it for the first time.