"Tim W" wrote in message
Books tell me various things but I still don't know.

Peel back the leaves and look at the colour - okay but I don't have enough
to spoil it by looking.

Not a good indication.

Stick your finger nail in and see if the juice is milky - as above

Yep.

Wait until the tassels are brown - just wrong afaics

Not the tassels. If the tassels are brown your corn will be soo far gone
even the poultry will have trouble eating it. Perhaps you meant to write
the silks? The silks on the cob should be brown but reasonably newly so.
Don't leave the cobs for long after the silk has gone brown or the corn will
become overripe.

Any other methods? One book says the time of picking is critical for
sweetness.

Yes as is the time from the garden to the pot. The normal advice is to have
the pot of water boiling as you pick the cobs.