How do you open efferve bottles?

"Efferve bottles" is not a common term. It's possible you're referring to one of these:

* Effervescent tablets: These are tablets that fizz when added to water. You don't need to "open" them, just drop them into the water and let them dissolve.

* Bottles containing effervescent tablets: These are usually plastic bottles with a child-resistant cap. To open them, you need to:

* Press down on the cap: There is usually a raised part on the top of the cap. You need to push down on this part to release the cap.

* Twist the cap: Once you've pressed down on the cap, you need to twist it counterclockwise to remove it.

* Bottles containing fizzy drinks: These are typically glass or plastic bottles with a twist-off cap. You need to:

* Hold the bottle firmly: Make sure the bottle is stable and you have a good grip.

* Twist the cap counterclockwise: It should twist off easily.

If you can provide more information about what you mean by "effervescent bottles," I can give you a more specific answer.