Homemade truffle oil made from fresh truffles isn't as strong as commercial truffle oil, and that's a good thing. Make sure to look at the recipes notes for tips on cheaper truffles.
1 gram food scale A smaller scale will help you be more precise
Ingredients
2cupsmild-flavored oillight light olive oil
½-1ozfresh black winter truffle or summer truffleUse more of cheaper truffles, and less of expensive ones.
¼-3/4teaspoonfine saltdo not omit for safety
Instructions
Slice the truffles ⅛th thick and weigh out 14-24 grams. Sprinkle half the salt in the bottom of the jar. Add the truffle slices and sprinkle the remaining salt on top.
Put the lid on the jar and allow to sit for 10 minutes, mix them around gently to distribute the salt.
Add the oil, top with a tight-fitting lid and refrigerate. After two weeks the truffle aroma will have infused, but it can be used after a week if you like the flavor. The oil will keep for months in the fridge, and should always be refrigerated.
Video
Notes
Cheap truffles
Truffles are expensive, but you can save money with the type of black truffle you buy. Tuber melanosporum, the black winter truffle is the most expensive. Summer truffles (Tuber aestivum) and musky truffles (tuber brumale) are cheaper (up to half the price). You can also get deals on more expensive truffles if you buy B or C grade truffles.
Infusing the oil without truffles in it
You can also infuse oil with truffle flavor by putting a screw in the cap of a mason jar, and screwing the truffle onto it, then closing the jar filled with oil not coming up far enough to touch the truffle. Cheesecloth can also be used. This won't make as strong of an infusion as sliced truffles, but it's cheaper.