Experts say that truffles are actually very sensitive types of mushroom because a slight change in weather or climate can affect its growth. In fact, there are a very limited number of areas where truffles grow and are being cultivated. These are mostly in Europe including Italy, France, Slovenia and Croatia; in the United including Washington and Oregon; in Asia mostly in some parts of the Middle East and in North Africa. Well, here s the science behind growing truffle mushrooms. They grow underground, which means they are not exposed to open air. Instead, they live near the roots of certain trees in the wild. And since they grow underneath the ground, they cannot disperse spores on their own through air. They rather depend on animals that feed on them to spread their spores. Truffles can be found in countries like France, Italy, Croatia, Slovenia, some parts in the Middle East and North Africa. They can also be grown and found in United States, particularly in Oregon and Washington. They can be found under the roots of oak, elm, chestnut, pine and willow trees. There are just few trees which are not associated to truffle growth, like maple and cedar trees. Oregon White Truffles Harvested from October to February, Oregon white truffles grow in northern California, British Columbia, western Cascade mountains, and Pacific Northwest. An Oregon white truffle has a white exterior, which turns brownish orange as it ages. 7. Oregon Black Truffles Larger and less popular than Oregon white truffles, the Oregon blacks emit a strong earthy smell when they are mature. For example, a Chinese truffle is different from Italian truffle, even though they are both black. The Chinese variety has weaker flavor, while the Italian variety has more culinary significance. Keep that in mind when you shop for truffles. To know the difference, smell them. The Italian truffle has a stronger odor. Truffles with soft spots tend to have worms in them. Avoid buying such truffles. Also, don t buy truffles that are rubbery, slimy, or spongy. If you are going to buy summer truffles, it must be golf ball-sized with only minor flaws. Choose truffles that have dark exterior colors and white or light color in their exterior.