French Fry Wars: FCA Affirms Deferential Claim Construction In McCain v. Simplot

In McCain Foods Limited v. J.R. Simplot Company, 2026 FCA 71, the Federal Court of Appeal (“FCA”) dismissed McCain’s appeal from a decision of the Federal Court concerning infringement and validity of Canadian Patent No. 2,412,841 (the “841 Patent”). The parties are competitors in the frozen French fry market.

The 841 Patent claims a process for treating vegetables, most notably potatoes, using a “high electric field” to reduce resistance to cutting without preheating or cooking the product.¹

In the underlying decision (2025 FC 1078), the Federal Court found that Simplot’s pulsed electric field (“PEF”) systems, operating at 1,000 volts per centimeter (“V/cm”) or more, did not infringe the asserted claims. Central to that conclusion was the Court’s construction of the term “high electric field” in Claim 1 as referring to electric fields in the range of approximately 2 to 200 V/cm, despite the claims not explicitly reciting any such range. The Federal Court further held, in the