I'm preparing to brew my first lager. I was thinking that a one gallon starter is in order (OG should be 1.048). But the Mr. Malty website is telling me that I not only need a one gallon starter, but that I need to pitch to vials into the starter wort. Is that really necessary, or will I get sufficient growth from one vial in a one gallon starter? FWIW, I don't use a stir plate. I rely on intermitten shaking.