It's fresh soda.

4 seconds sound clip from the The Remains of the Day movie soundboard.

You can hear this line at 01:05:49 in the Blu-ray version of the movie.

Quote context

[...]

- And in your opinion, what's going on up there has moral stature, does it? Wish I could be so sure. But I'm not.

- I heard some very fishy things. Very fishy.

- I hear nothing, Mr. Benn.

- Listen. That's so touching, isn't it?

- To listen to the gentlemen's conversations would distract me from my work.

- It's fresh soda.

- Would you be joining us for a drink?

- Oh, thank you very much, but it's very late and I have an early start. Good night.

- Good night, Mr. Stevens.

- Good night, Miss Kenton.

- Good-looking woman.

[...]