Can you refreeze ice cream after it thaws?

Yes...and no. It really depends on what you mean by "refreezing" it.

First of all, one has to consider food safety. If it was melted at room temperature, then there is a very good chance that bacteria might have formed and it'll no longer be safe to eat.

But for the same of argument let's say someone accidentally put it into the fridge and not the freezer. Then the ice cream would melt, be at a safe temperature and would be safe to eat. However just freezing it will not turn it back into ice cream. You'll just have a huge block of ice.

To make ice cream, you need to churn it. Churning is the process where you keep it moving to incorporate air into the mixture. This is done is done by the paddles in most ice cream makers. As the mix is cooled and it starts to freeze, the paddles keep the crystals from forming one solid lump and folds in air.

So, *if* the product was kept at a safe temperature, and *if* you run it back through another ice cream maker...then yes you can turn melted ice cream back into ice cream.

Once maybe, but not worth the risk in doing so regularly.

When ice-cream thaws all the air that was put into it disappears. Also the ingredients tend to separate and form layers. Re-freezing it results in something that is not like ice-cream as we know it! It usually has a gritty, granular texture and a layer of, basically, flavoured ice forms at the bottom.

It's not something that's pleasent to eat. Try it and see what you think.

I wonder why there have been so many people lately melting ice-cream!

yes, but the texture will be a little different.

No - the texture will be wrong and bacteria will have had a chance to grow, not a good idea, not pleasant to eat

Not really. It won't taste the same (texture-wise).