Clean Water, Clean Ice, and Eating Street Food
Water
Everybody knows that the water in Mexico is bad to drink for foreigners, as the old pipes in Mexico City and poor filtration may mean bacteria in your tap water. Even if you have filtered water at your hotel or AirBNB, go ahead and buy bottled water. It's available everywhere and an easy way to have peace of mind about your health while in Mexico!
The water you're served at nice, upscale restaurants will be completely fine. Otherwise, just stick with bottled water, especially you're at a market of street stall. Ice at a nice restaurant will be clean. You'll notice that people will buy ice in bags from the grocery store, which is made with filtered water. Whenever you see ice that's got a hole in the middle of it, basically like donut, that's ice that has been made with purified water. Be careful of ice at mercados, or street food places. You'll probably want to avoid the ice there.
Street Food
Mexico City is known for its great street food, but sometimes it can be intimidating and hard to figure out what is an OK place to eat at. The best way is to ask a local. I recommend AirBNB tours for their explorations of street food. I that I think this is the best way to experience street food safely, because local guides know the exact places to go to and the exact things to eat which will not make you sick.
If you do want to eat street food, go to the places that have long lines with them. Places that women and children are going to, that will be completely fine for you to eat at. When you see business people eating there, that will be fine street food for you to go to. Just be careful of raw things, for example, lettuce or some salsas. If those have been sitting out in the sun in plastic containers, those things you probably should avoid on your street food. Also, note that sometimes they will -- for example if you're getting a torta sandwich -- dip the bread into grease and cooking liquid. This is delicious but it may also upset your stomach, so just be aware of that.
Here are some street food tours:
-Explore downtown taco joints with this street food tour!
-Even vegans and vegetarians can enjoy street food with this AirBNB tour!
Mercado
Mercados are the markets for every neighborhood. You can buy anything! You can buy any food you need, you can buy a hammock, you can buy bags, you can buy sandals. By an American standard, you may find mercados to be a bit run down, or to have some unpleasant smells.
I recommend if you want to go a mercado: Find a tour. There are tours on Airbnb that will take you to some of the best mercados. Going to a mercado on your own will be a very overwhelming experience, and if you don’t speak perfect Spanish you will have a hard time navigating them.