Have you noticed that you might be quite turned off in the morning when you breathe in while yawning and notice the smell is really bad? Interestingly, it doesn’t have anything to do with what you’ve eaten—it’s all about bacteria.

Usually, bacteria thrive in our dry mouths. While sleeping, we produce less saliva, which means that a nice long sleep offers optimal conditions for bacteria to feed on leftover food particles and dead cells in and around the oral cavity, from your gums to your teeth and tongue. In turn, the bacteria leave behind waste that has sulfur in it—and it is the sulfur that causes your bad morning breath.

There are a few things that can be done to prevent such bad breath. You can try a tongue scraper! Get that gross stuff off the back of your tongue, but make sure it’s swallow-safe material you’re using. Or, if you’d prefer, Listerine strips also work. They stimulate saliva, which helps counteract bacteria activity.

So if you want to keep your mouth moisturized enough or you want to try staying away from the food part of the Allium family such as onions, garlic, leeks, and even shallots. Those particular foods contain plenty of sulfur and can also cause bad breath! Steer clear of them if you don’t want the person waking up next to you to be horrified. And remember: brush regularly and floss!

Most people expect their freezer to keep their food fresh and safe from spoilage for months. Unfortunately, this is not always the case, as over time, a funky smell tends to develop in most freezers. But where does this smell come from, and how can the problem be fixed?

Microbes like bacteria, yeasts, and mold are typically responsible for causing bad smells in freezers, which can occur when the temperature rises due to power outages. Hot food being put straight into the freezer, or from food spills and open containers, provides an opportunity for the microbes to thrive. While some of these microbes may survive freezing and produce pungent chemicals and volatile organic compounds, which are the pleasant aromas we experience when we eat, it is important to note that uncontrolled food spoilage caused by contaminating microbes can be problematic, especially when they can cause disease.

The freezing process can lead to undesirable odors not only due to microbial growth but also because it causes physical changes to food that often enhance their breakdown. This results in phenomena such as freezer burn and ice crystals caused by salt rejection – a process where, depending on the speed of freezing, salts can become concentrated as pure water freezes at a higher temperature than water with things dissolved in it. These include sugars and salts, and the phenomenon is also observed in the formation of icebergs.

During the freezing process, organic molecules in food become concentrated and expelled, and if they are volatile, they can move around the freezer and stick to other surfaces depending on their hydrophilic or hydrophobic properties. Hydrophilic volatiles also contributes to unpleasant taste as they stick to surfaces like silicone ice cube trays and also cause bad odors. Additionally, as domestic freezers are typically attached to refrigerators and share a single cooling source and airflow channel, odors from foul-smelling food in the fridge can migrate to the freezer, compounding the problem.

To prevent and eliminate bad smells in the freezer, the food should be covered in an airtight container to slow the release of aromatic compounds and prevent the absorption of other smells. The spoiled or freezer-burned food should be discarded, and the fridge should be inspected for bad-smelling items, which should be discarded. All items should be removed from the freezer, and then the surfaces should be wiped down with warm soapy water or a baking soda solution after taking out the shelves. Any spills and crumbs should be cleaned regularly. If the smells persist even after all these efforts, baking soda can be placed inside the freezer, or a deep clean should be considered.