A deed does not have to be recorded. An unrecorded deed can be effective as between the parties to the deed and anyone who has knowledge of the deed. Recording the deed with the county register of deeds makes it part of the public record and give everyone actual or constructive notice of the transfer.
A deed must be “delivered” to the grantee (the person who is getting the property in the deed) to transfer title to the property. “Delivery” is a legal concept which in not necessarily the same as physical delivery. If you keep possession of the deed, you have not delivered to your sons and the effect legally is the same as if there is no deed.
When you die and still have possession of the deed, the deed is no longer effective to convey title and, assuming that you are the sole titleholder of the property, the property would have to be probated.
The concept of quit claiming title to your property to someone and having them not recorded it until after you die is sometimes referred to as a “poor man’s will”, since the intent is for you to keep the property until you die (or sell it if you want to) and to have it pass to your children upon your death. Legally, this concept is not valid. However, it is done based on the premise that no one will know that the deed was never delivered before you died.
There are a number of other ways to deal with this situation. The best way is for you to set up a trust, known variously as a revocable trust, a living trust, a grantor’s trust, a settlor’s trust or an estate planning trust. These are all names for the same type of trust. You name yourself as the trustee and the primary beneficiary and you quit claim the property to the trust (actually to yourself as trustee of the trust). This avoids the transfer tax, does not remove the property tax cap, avoids probate and allows to sell or mortgage the property while you are alive or remove it from the trust are change the successor beneficiaries if you change your mind as to who you want to ge the property after you die.