Everyone is full of cooking rules that they are only too willing to share with you, but the accepted wisdom is not always correct.

Here are 10 of the most persistent kitchen myths, and we will bust every one with science to prove to you that just because Gordon Ramsay and your grandma say it’s true, it doesn’t mean that it actually is!

1. Bad Eggs Always Float in Water

This myth has been doing the rounds for decades but what is the reasoning behind it? Since the air pocket grows as eggs get older, seeing if one floats or sinks in water is a fast way to tell if it’s good or bad. If the egg sinks, it’s fresh, and if it floats it should be thrown away or used for baking.

The reality is that a real bad egg doesn’t need the float test – you’ll be able to tell just by looking at it, says Marianne H. Gravely, a Senior Technical Information Specialist.  Eggs that float but otherwise look normal won’t make you ill, and the larger air pockets are better for hard-boiling since it makes the eggs easier to peel.

2. Salted Water Boils Faster

Everyone seems to add salt to the pot when it’s put on the heat, from your parents to celebrity chefs, and the reasoning is that it makes the water boil faster.

Actually, it does the opposite! Science tells us that salt increases the boiling temperature of water, and this reaction happens when something is dissolved in a pure solvent, not just with salt and water. The opposite happens too, and it’s called ‘freezing point depression’, just in case you were wondering.

Adding salt to water helps to add flavor to the food you’re cooking, but add it after it’s already boiling, not before.

3. Throwing Spaghetti on the Wall or Ceiling to Test if it’s Done

spaghetti with clams

This has been regarded as a fun way to test if your spaghetti is cooked properly, but the source of this myth isn’t clear.

While cooked spaghetti does stick to walls or ceilings, it’s not an accurate test for whether it’s properly cooked. Pasta can be soft on the outside, and hard on the inside. Overdone pasta can also stick to surfaces too, so the best way to test is to actually taste some of the pasta.

4. Hanging Bananas Stops Them Ripening too Fast

This is one of several methods people use to stop the fruit ripening too fast. The others include storing them separately, and covering the tops to avoid air circulation.

Tests have proven that there’s no significant change in the speed at which bananas ripen, so just keeping them in the fruit bowl is fine.

5. Espresso Contains the Most Caffeine

Everyone assumes that espresso coffee has the most caffeine in it, but science says that it’s the length of time the water is exposed to the coffee grounds that determines the caffeine content, not the strength of flavor.

Espresso has less caffeine than drip coffee, and cold brew has the most of all. Don’t let that stop you drinking your morning shot, though. According to Christopher Hendon, an assistant professor of chemistry, it’s the perception of a drink’s strength that can be as important as actual caffeine levels.

6. MSG Causes Headaches and Makes You Hungrier Quicker

This myth comes from a now-debunked bit of scientific research. MSG, or monosodium glutamate, is a type of sodium salt found naturally in many foods. It was first extracted from kelp, and identified as the source of the ‘umami’ flavor.

The New England Journal of Medicine began to speculate that MSG was causing headaches, pain, and even heart palpitations. Modern researchers think that the fear of MSG, which is mostly found in Asian cooking, was the product of xenophobia. Even today, this fear of MSG still exists, although many studies have proved it to be safe.

7. White Wine for White Meat, Red Wine for Red Meat

This myth is universally held to be true, but there are plenty of reds that go with white meat, and vice versa.

Lighter reds, such as Pinot Noir, can match well with lighter, more delicate flavors, and bolder white wines can hold their own against heavier flavors.

If you’re in doubt, choose sparkling wines, which are almost always white. They pair with nearly all food choices, and taste great.

8. Spoiled Food in the Fridge Can Make You Ill

We’ve all been horrified to find that the carton of milk in our fridge is a day past its expiration date, and flung it out sharpish.

However, the kinds of microorganisms that contribute to food spoilage rarely make you sick. The bacteria that cause food poisoning grow at room temperature and can’t be detected.

That means if you accidentally take a bite of leftovers past their prime, or a sip of expired milk, it is rare that you would get sick from it. You can generally rely on smell and sight to determine if food in the fridge is ok to eat, but you must be careful with meat and eggs because these grow salmonella at room temperature.

9. Green Potatoes are Poisonous

Your granny probably told you this one, but it has been declared ‘mostly false’. Yes, the green coloring that you sometimes see under the skin of a potato is a natural toxin called solanine, but it won’t harm you unless you eat a large amount of it – around 4 pounds of potatoes at one sitting!

10. You Can Tell if Chicken is Cooked by the Color

There is no reliable way to tell by sight alone that your chicken is safely done. Whole chickens can have some pinkness near the bone while still being safe to eat, but if you wait for your whole cut to turn white, you’ll likely end up with dry, overcooked chicken.

The USDA has found no reliable way of testing for doneness other than by using a food thermometer. Chicken has to reach 165 degrees F internally to be safe to eat, so you can’t tell reliably just by hacking open your chicken to look. Invest in a digital food thermometer instead.