4.5 kg peeled raw potatoes (3 kg for grating; 1.5 for mash) or 2:1
white bread to make croutons (optional)
30g butter (optional, if making croutons)
40g salt in 1 litre of water
4-5 l water
Add 4-5 litres of water into large pot and start to bring to a boil
Add 1 litre of water and salt into a separate pot and bring to boil
Grate 3 kg of potatoes into a large bowl
Separate liquid and potato starch from grated potatoes by pouring the mash into a linen sack or cloth and then squeezing to remove all the liquid. Squeeze liquid into a separate bowl (don’t throw away). Potatoes should be dry. Set potatoes aside in a separate bowl.
Let the liquid sit for a while until the potato starch separates from the water
Boil 1.5kg of [the remaining raw] potatoes gently until soft in 1 litre of salted water (#2 above)
Mash the boiled potatoes until smooth; add water (that was used to boil the potatoes) as necessary to get smooth
Once water and starch have separated (#5 above), pour off water (and save) so that only the starch remains.
Add grated potatoes into the bowl with the starch
Add the boiled and mashed potatoes into the bowl with the grated potatoes and mix the two together [if the mixture does not thicken enough then the potatoes did not have enough starch]
Form dumplings out of the mixture. Optional: add croutons in the middle
Add dumplings to gently boiling water started above (#1). Water should be no more than a very gentle boil; add dumplings and cook for 20 minutes. They should rise to the top when done
Potatoes: the recipe needs high-starch potatoes, in Canada, Russet potatoes will do.
To prevent rusting (potatoes turning colour, becoming grey): after potatoes have been peeled, place sliced potatoes into cold water with some vinegar or lemon juice; work quickly to reduce time between when the potatoes are mashed to when they are formed into dumplings and boiled.