It is a requirement of a title transfer that control of the property be relinquished from the initiator of the transfer and acquired by the other individual at at the same time.
If there is any period of space between the relinquishment and acquiring of the title, then it is not a title-transfer, but abandonment, and a third party could technically interject and homestead the good within that time-frame.
Both parties in a transfer must have the goal of the transfer going forth.
Contracts are enforceable, as if the the one transferring the property does not physically relinquish their control of the property once the transfer has gone through, they have implicitly committed theft, as they would be using it without consent of the owner.
The prior property owner agreeing to the contract which transferred their title acts as evidence that they wish to relinquish control. They cannot deny this without contradiction.
Contracts are enforceable.
Mere promises are not enforceable.
The title-transfer theory of contracts holds that only contracts which define terms of the transfer of title to alienable property are legitimate (enforceable).
Contracts can include transfers under certain conditions.
A contract is not a piece of paper. A piece of paper may be used, and can serve as evidence of a contract existing, but it is not required.
A contract can be any form so long as it is communicated and agreed upon by the parties in question.