One example where almost all authors go with "is": there are thousands of recipes saying to heat butter until it "is" a particular consistency, versus only a handful saying to heat it until it "has" a particular consistency. Compare https://www.google.com/search?q=%22until+the+butter+is+the+c... vs. https://www.google.com/search?q=%22until+the+butter+has+the+....
One example where almost all authors go with "is": there are thousands of recipes saying to heat butter until it "is" a particular consistency, versus only a handful saying to heat it until it "has" a particular consistency. Compare https://www.google.com/search?q=%22until+the+butter+is+the+c... vs. https://www.google.com/search?q=%22until+the+butter+has+the+....