As Rachel and I walked home tonight, we made a stop at Gem Spa, a scruffy bodega in the East Village and just one of the many eateries in the city claiming to sell ‘New York’s best egg cream’.

Even though we have zero experience to draw from, we decided to see what they had.

Now, I’m still not 100 per cent sure what an egg cream is. I do know it’s a New York classic, a sort-of milkshake fountain drink that was born out of Brooklyn in the 1800s. The men behind the counter said it contained seltzer water, milk and syrup – usually vanilla or chocolate.

It doesn’t seem quite right. And where does the egg come in?

To be fair, it was pretty delicious. I went for the vanilla flavour and, after some vigorous stirring, it came with a good foam on top and somehow defied science by not curdling. It tasted like a watered-down ice cream, or a not-so-sweet coke float.

I asked the shop owners what made this egg cream better than any other in the city, and they insisted it was their use of ‘crunchy milk’ – that is, milk that is partly frozen.

The verdict? I don’t understand the egg cream. While it was pretty tasty, I still can’t really get my head around how water and milk stirred together is any good.

But if I don’t have it again, how will I know that Gem Spa really does sell the best in New York?