For AG Pilsner do I have to do a step mash?

Just got a fridge and am dying to try brewing a pilsner.. But all I have is a converted cooler so I am unable to do step mashes.. Can you make a pilsner with a regular one step infusion? If so, how much will it change the flavor?

Thanks!

I make pilsners with decoction mashes. It changes the flavor a lot.

I make pilsners with single infusion and they're just fine. As long as your processes and ingredients are dialed in, you'll be fine.

So in short, of course not. A single infusion will make beer. I don't think a regular step mash would do much for you because there is no need for a protein rest or any other rest for that matter, but the decoction will give you a lot of melanoidins that you otherwise will not get.

Even though it's not the same you could use a little Melanoidin malt in your single-infusion Oktoberfest to simulate a decoction.

It depends on your malt. It is highly doubtful that you "need" one. If it's inconvenient to do, don't bother. I brewed a German Pils with a Hochkurz-style step mash (~142°F/158°F) and it turned out very malty. You could do a step-infusion mash (add boiling water to get to next step) if you wanted to. And with a Hochkurz-style schedule, you wouldn't need to add all that much water to get to the next step.

Whatever you decide, don't do a rest below ~135°F with modern 2-row pilsener malt (or if you did, keep it very short). It could negatively affect foam stability.