If the fat doesn't blind you, you'll die of botulism from eating rancid butter.

Sometimes rancid butter is used which gives the tea a different taste.

Count Thraxton looked as if he'd just taken a big bite from bread spread with rancid butter.

That is the same compound found in rancid butter.

If the odor of rancid butter doesn't get you, the crunching and slurping will.

The normal butyric acid is the one common in rancid butter.

On arriving, after having walked cold and famished, they were given a whole slice of bread, spread with rancid butter.

You'd probably find you didn't care about anything except they put rancid butter in your tea.

By comparison, rancid butter smells better, at least if it is not too spoiled.

They had nothing left but a small amount of rancid butter which they offered us in exchange.