Where are you and do you have any idea what variety of lemon you have?

Please also takes pics of the fruit and the foliage. Are you SURE it's a lemon?

there is a fruit forum.. and i believe a citrus forum .... but if you like us better.. the heck with them ... but if we fail.. you know where to go ...

ken

maybe a bitter rootstock like a citrange, grew up in place of the lemon

Are you eating lemons by themselves? That's a bit of a strange habit.

You don't have to 'eat' a lemon by itself to distinguish its taste. And tasting a lemon is a good way to determine how to use it. Eurekas, Lisbons, Meyers all taste different.

'.....we have a lemon tree....'

You are making an assumption that this is, in fact, a real lemon tree. It could be the rootstock has overtaken the scion, as davidrt suggests.

did you plant it from a seed?

Rootstock has overtaken my lemon tree. what can I do with bitter lemon?