In the US, the default potato is the Russet. It has a good flavor and is well suited to high temperature cooking. I'd be practically certain that is what is in

In the US, the default potato is the Russet. It has a good flavor and is well suited to high temperature cooking. I'd be practically certain that is what is intended. It's possible it means a semi waxy white potato, which would be contemporaneous with the historical setting. It is very unlikely to mean any of the thousands of more exotic varieties.