You know olive oil is healthy. But not all olive oil is of high quality. Here, Chef V schools you on what constitutes healthy, organic olive oil.

When weather cools and days are shorter, I crave comfort food.

Here in sunny San Diego we have to wait a little longer to feel the cool nights. But when temps dip into the high 50s at night - Brrrrr. That's the time to bust out the flannel sheets and the comforter!

And it's also time to cook comfort food dishes with seasonal veggies. Below, I'll share with you one of my favorite fall recipes: Mediterranean Butternut Squash and Carrot Stew with Quinoa. (If you love the recipe, you can get more delicious ones in my book, Making Cleansing Easier.)

As you'll see in the recipe, one of the ingredients for both the stew and quinoa is olive oil.

Not too long ago, I read a report that up to 80% of olive oil sold in stores is either fake or of really low quality. In fact, the problem is so pervasive in Italy, there's a special police unit devoted to olive oil fraud! Many olive oils are cut with food coloring or vegetable oil. This makes it easy for food fraudsters to make some easy profit on unsuspecting customers.

In light of this shocking statistic, before you reach for a bottle of Italian extra-virgin olive oil, learn these tips about finding a truly high-quality olive oil....

Healthy Organic Olive Oil: location matters

You might come across a bottle of olive oil that looks legit. On the back of the bottle, it says the origin of the olives is Spain, Greece, and Italy. These three Mediterranean countries might be home to delicious olives (I especially love cantanzaro olives, yum!). Therefore, you might think, wow, great olives from the best places in Europe in one bottle. However, the problem is the olives shouldn't derive from more than one origin.

The reason why is that there are a few things that turn olive oil rancid: air, light, heat, mixing with other oils.

When olive oil comes from more than one location, there's too much air from the bottling process. So instead of buying healthy organic olive oil, you're really purchasing olive oil that could already be rancid before you open the bottle.

Organic Olive Oil: Where to buy local

If you're in the U.S., California has some amazing-quality healthy olive oil. If you want to know for sure that an olive oil is of high quality, check out the California Olive Oil Council (COOC). You can enter your zip code on their website, and it will show you which stores have COOC-certified olive oils. Some of them are even organic olive oil, which I prefer to buy.

The highest-quality and most affordable olive oil is sold at Trader Joe's, under the label California Estate Extra Virgin. It's only $5.99 for a 500ml bottle. It's not certified organic olive oil, nor is it COOC-certified, but it's still a very high-quality oil. All large producers in California who produce over 5,000 gallons are required to comply with mandatory state quality standards. So whomever is supplying Trader Joe's with the delicious olive oil I love is certainly producing at least 5,000 gallons.

And if you live on the East Coast, you can get high-quality olive oil from Georgia. Yes Georgia, which, in 2011, became the first state east of the Mississippi to harvest olive oil.

Healthy Organic Olive Oil: Buy Extra Virgin, Never Light

What is extra virgin olive oil? In short, it's olive oil that was produced without chemical processing. Instead, extra-virgin olive oil extraction is via mechanical pressing. In addition, the extra virgin healthy olive oil is lower in acidity.

There's no reason to ever buy light olive oil. "Lite" does not mean it's a healthy olive oil. On the contrary, lite or light olive oil undergoes extra processing. This denatures the oil. Also, virgin, fine and light olive oil are more acidic than extra-virgin.

Speaking of light, never buy olive oil if it doesn't come in an opaque, dark bottle. If it's a clear bottle, the light will ruin the oil.

One reason the Mediterranean Diet is so popular is because it emphasizes healthy monounsaturated fats like extra-virgin olive oil (EVOO). EVOO is one of the healthiest foods for your heart.

Organic Olive Oil: Good or bad for weight loss?

But if you worry about the calories in organic olive oil, limit your intake to about 3 tablespoons per day. Olive oil is a calorie-rich fat, which is a double-edge sword. On one hand, the 100+ calories per tablespoon will help keep you full and prevent cravings. On the other hand, though, all those calories may lead to weight gain if you don't burn off those calories through exercise. So have healthy organic olive oil often, just don't drench your salad with it.

Don't cook with organic olive oil at high temperatures. Extra-virgin organic olive oil has a smoke point of about 375 degrees. Once it's smoking that's a sign it's turning rancid. You can lightly sautee with organic olive oil. However, I prefer coconut oil for higher temp stir-frys.

Healthy Organic Olive Oil: First-Press is Best

If you have the money, spring for small-batch, first-press olive oil. First-press olive oil contains the highest amount of antioxidants. You won't often find first press (aka "Olio Nuovo") olive oil in stores. That's because the first press doesn't yield that much olive oil. Most olive oils that you buy in conventional stores are derived from olives harvested late in the season. This results in greater yields and therefore, more olive oil that can be sold. However, even if you don't buy a first-press olive oil, if you get a COOC-certified oil or similar high-quality, it's still very good for your health.

I prefer to buy food that comes from local sources. In fact, every single one of our ingredients in our Green Drinks and Detox Soups either grow on our farm or from nearby farms. But if you want to buy extra virgin olive oil from, say, Italy, here are a couple things to keep in mind. The bottle should have a harvest date and a geographic origin and EU certification.

Now that you know a few key facts about what makes olive oil high quality, it's time to share with you my nourishing soup that I love to make in the fall. So without further ado, enjoy the recipe!