Can I demure an answer to the civil lawsuit?

It is rare, but yes, you can demur to an answer. Specifically, California Code of Civil Procedure section 430.20 provides a mechanism for a plaintiff to demur to a defendant’s answer: “A party against whom an answer has been filed may object, by demurrer as provided in Section 430.30, to the answer upon any one or more of the following grounds: (a) The answer does not state facts sufficient to constitute a defense. (b) The answer is uncertain. As used in this subdivision, "uncertain" includes ambiguous and unintelligible. (c) Where the answer pleads a contract, it cannot be ascertained from the answer whether the contract is written or oral.” Generally speaking, the determination whether an answer states a defense is governed by the same principles which are applicable in determining if a complaint states a cause of action. (South Shore Land Co. v. Peterson (1964) 226 Cal.App.2d 725, 732.) Thus, a demurrer reaches only the contents of the pleading and such matters as may be considered under the doctrine of judicial notice, the allegations of the pleading demurred must be regarded as true, a demurrer does not admit contentions, deductions, or conclusions of fact or law alleged in the pleading. An important difference is that in the case of demurrer to the answer, the defect in question need not appear on the face of the answer. The determination of the sufficiency of the answer requires an examination of the complaint because its adequacy is within reference to the complaint it purports to answer. A demurrer to an answer must be filed within ten days after service of the answer, unless this period has been extended by stipulation or court order. (Cal. Code Civ. Proc. § 430.40(b).) A judge may extend the time to demur in furtherance of justice and on any proper terms. (Cal. Code Civ. Proc. § 473(a)(1).) Cal. Code Civ. Proc. § 430.50(b) states that, “A demurrer to an answer may be taken to the whole answer or to any one or more of the several defenses set up in the answer.” California Rules of Court, Rule 3.1320(a) states that, “Each ground of demurrer must be in a separate paragraph and must state whether it applies to the entire complaint, cross-complaint, or answer, or to specified causes of action or defenses.” Therefore, even if the demurrer to one individual defense is overruled, the demurrer to each separate affirmative defense will be sustained or overruled on its own merits.