What potato slice thickness is best for Pommes Anna?
Aim for 1/16 inch slices, about 1.5 to 1.6 mm. If you can bend a slice slightly without it snapping, you are in the sweet spot. Thicker slices can work, but the center takes longer and the layers look less refined.
Do I need a mandoline?
It is not mandatory, but it is the easiest way to get even slices fast. If you use a knife, go slow and focus on consistency. Uneven slices are the main reason the cake bakes unevenly.
Should I rinse the potatoes?
No. Rinsing washes away surface starch that helps the layers lightly cling. Just slice and layer.
What potatoes are best: Yukon Gold or russet?
Yukon Gold is my favorite here because it turns creamy and holds together nicely. Russets are starchier and can get very crisp, but the slices are a bit more fragile, so be gentle when layering and flipping. Either will work if you slice thin and pack the layers tight.
How do I keep potatoes from turning brown while I work?
Best move is to slice and assemble right away. If you have to pause, you can hold slices in cold water briefly, then dry them very well before layering. Just know you will wash off some starch, which is part of what helps the layers cling.
Why is my Pommes Anna sticking?
Usually it is one of three things: not enough butter on the bottom, the pan surface is too rough, or you tried to flip too early. Generously butter the pan, use parchment if you want an insurance policy, and wait until the edges are clearly browned.
How do I know when it is ready to flip?
Look for deeply golden edges pulling slightly from the pan and a tender center when you poke down with a thin knife. It should also move as one piece when you gently jiggle the pan. If the middle still feels firm and resistant, give it more time before flipping.
Can I add cheese or cream?
You can, but then you are drifting into gratin territory. Pommes Anna is meant to be butter-only so the layers stay distinct and the crust stays crisp.