Your situation is called "transmutation of community property into separate property". Since he signed the deed to gift the house to you, it probably satisfy CA's requirement. see below.
I am not a lawyer practicing in California. This is not a legal advice.
"In contrast, transmutations occurring on or after January 1, 1985, require a written declaration explicitly stating that the parties intend to effect a change in the character of ownership regarding the property. Furthermore, this declaration must be acknowledged and accepted by the party whose interests in the property are adversely affected by the transmutation."
A transmutation can come in the form of other legal instruments, such as property records and contracts.
The following instruments can be used to effect a transmutation in property:
- Wills: Before January 1, 1985, a statement in a spouse’s will that claimed all of the couple’s property to be part of the community estate was sufficient to effect a transmutation. However, after January 1, 1985, statements in wills were held to be inadmissible as evidence of a transmutation in proceedings that are commenced before the testator’s death.
- Marital agreements: Premarital and postmarital agreements may effect a valid transmutation.
- Title documents: Property acquired under joint title between the parties is presumed to be community property:
