Home › Laboratory Exercises › Laboratory Exercises (Select smooth medium sized)
Laboratory Exercises (Select smooth medium sized)
1. Select smooth, medium sized potatoes. 2. Scrub clean with vegetable brush. 3. Place on baking sheet or in dripping pan and bake in hot oven until soft. 4. Press between the fingers in a towel to tell when they are done. Do not stick a fork into the potatoes while they are baking. 5. When they are done roll between the hands in a towel and break the skin to allow the steam to escape. If the steam is allowed to cool and condense in the potatoes they will be soggy. 6. Serve very hot with salt and butter.
Boiled Potatoes. 1. Select potatoes of same size, so that they will cook evenly.
A domestic-science lesson in baked potatoes, written as lab procedure. The instructions are sound; only the oven heat and a few habits need translating.
- "Hot oven"In period usage roughly 400-450F. At around 425F, medium starchy potatoes of 7-9 oz will usually take 45 to 60 minutes; the recipe gives no time and relies on the squeeze test instead.
- The hinge: release the steamStep 5 is the whole point of the exercise. Break or pierce the skin the moment the potatoes leave the oven; trapped steam condenses back into the flesh and gives you a dense, waxy interior instead of a floury one.
- Why no fork while bakingThe recipe does not say; it simply forbids it. The towel-squeeze test in step 4 is the doneness check the exercise intends, and a skewer or thin knife slid in at the end will confirm it.
- Choice of potatoThe recipe specifies only smooth, medium size. For a mealy result you want a starchy baking type, sold now as russet or Idaho; waxy red or new potatoes will not go floury no matter how well you vent them.
- Scrubbing and skinScrub under running water and dry thoroughly. A dry skin crisps; a wet one steams. Rubbing the dry skin with a little fat and salt before baking is not in the original.
- Pan or no panThe recipe offers a baking sheet or a dripping pan as the vessel at hand. Potatoes set directly on the oven rack brown more evenly on the underside.
- YieldOne potato per person as a side dish. Serve immediately; held in a warm oven the skins soften and the flesh compacts.
- The trailing line"Boiled Potatoes. 1. Select potatoes of same size" is the start of the next exercise in the book, cut off mid-list. Treat it as a note rather than a step of this recipe.
This comes from a school manual in household arts, part of the domestic-science movement that put cooking into American classrooms from the 1890s onward under the banner of applied chemistry and physics. That is why a baked potato is called a laboratory exercise and numbered like a procedure: pupils were meant to learn a principle, in this case what steam does to starch cells, rather than a family dish. The instruction not to prick the potato and to break the skin at once still holds. Potatoes themselves were cheap, storable and unglamorous, which made them ideal teaching material.