What's the science behind making German potato dumplings (Knödel) fluffy but not fall apart?

Hanno Fietz
  • What's the science behind making German potato dumplings (Knödel) fluffy but not fall apart? Hanno Fietz

    First off, I'm German, so you would think I know, but it seems traditional cuisine has not been passed down my family tree.

    This question really consists of two parts:

    • What makes potatos dough (or I guess, starchy dough in general, there's all kinds of dumplings, there's pasta, etc) keep its shape when you boil it in water? This may extend to some degree to deep frying.
    • What properties make balls of dough "fluffy" or "textured", but not "tough", "rubber-like" etc.? I guess this will go somewhere along the lines of what structure the starch granules form with the water, how stable it is, and how dense.

    There is about a million recipes online for cooked, raw, and 50-50 knödels. Some have egg, some don't, and just about everywhere there's people asking how to do them right. There's also a question to that here on this site.

    However, it's hard to get some actual information on the key aspects (this is a problem I have with recipes in general). I'm pretty sure there ought to be no egg and not a lot of flour in the dumplings. I'm also certain that either all cooked, all raw or half-half are common and widespread varieties, but there it stops.

    I would like to find some science based instructions, the kind of articles Kenji runs on The Food Lab. It looks like most recipes have some way of enriching the dough with starch above what's in the potatoes anyway, by draining water from the potatoes and adding starch powder. The father of a friend wraps the potatoes in cloths and puts them through the spin cycle of the washing machine, which (because of the preceding meticulous cleaning of the latter) is a tedious procedure that's only done for Christmas.

    Millions of grandmas have reached the proper end result via various routes, using plain ingredients and unsophisticated equipment, so there should be some basic principle at work, which can be analyzed with science, very much like with roasting beef or frying potatoes.

    Maybe, we could dig up something about related recipes, like gnocchi, which would be helpful.

  • Your dealing with a few things here. First is starches in general. The thing to know about starches is how they gelatinize and at what temperatures.

    This powerpoint is a nice primer on that topic. www.cfs.purdue.edu/class/f&n630/gelatinization.ppt

    Basically your dealing with amylose and amylopectin, together they are what we know as a starch. When they come in contact with water the starch cells begin to swell and when their gelatinization temperature is met they burst and release their contents into the medium they are in. In the case of a dough ball, your dealing with tons and tons of little cells being held together loosely at first by the physical pressure of kneading them into balls and then when the heat causes the starches to gelatinize they adhere to one another kind of like being caught in a net.

    Now the fluffiness portion of the question can really depend on how the dough is being cooked. For something like a dumpling being cooked in the boiling water, one would typically want to work the dough as little as possible to avoid making it too dense and if using flour to lessen the gluten formation that can make it very chewy like bread. Some recipes call for leaveners that can create gas bubbles when heated to a certain temperature and then through gelatinization the bubbles are trapped inside the dough and create an airy texture.

Related questions and answers
  • to low-starch potatoes that don't fall apart when cooked. Sometimes called roasting potatoes (US). New potatoes behave like waxy potatoes, even if they come from a variety used for baking. Mealy..., or the device on which it is cooked. Tools / Equipment / Non-food items : parchment paper (US, CA) is greaseproof paper (Ireland/ UK, NZ) and baking paper (AU) stove (US, CA, AU) is also range (US... or add additional items. The comments are getting long, so use answers for discussion of specific concepts if necessary. If you're not sure what a term means, ask it as a new question and tag

  • away, mostly if you gift them loafs of bread you make with that wood). What are the risks of using those woods for fire lit in the same place where you'll put food? I'm quite sure there is no biological hazard with them: any virus or bacteria in the pallets, or bugs in logs will definitely be destroyed by the fire temperature (over 800C/1,500F). What I'm concerned about is: I don't know...I have recently made a brick wood fired oven. It's a black / dirt / Roman / traditional type of oven: where you burn the fuel (typically wood) in the same chamber where you put the food to be cooked

  • Frying - Oil foams BaffledCook

    I am relatively new to deep-frying. Having seen the questions about oil reuse and conservation, I'm still at a loss about what's going on with my oil... My sunflower oil foams like crazy. I've been... of water, and I guess that has something to do with it. Also, I noticed the frying takes longer with the foaming oil. Edit: I've tried poaching(?) the French fries, but they foam during poaching. Then when frying, they really foam. I have to keep an eye on it or the oil spills over the top. Anything I can do about it, or should I just go ahead and discard the oil altogether? Edit: Serious Eats has

  • in the same box as the whipper itself? I have to assume that iSi knows what they're doing and it was me that screwed up; but how? What did I do wrong and how could I have fixed it? Some possible...I recently got myself an iSi Creative Whip and have been having a lot of fun playing around with it. Tonight I tried one of iSi's recipes, which uses the following ingredients: 250 g goat cheese... with) with a rubber spatula and spread it on some crisp toast; it was delicious in spite of not even being remotely close to an espuma. I'm well aware, as the manual makes sure to mention about half a dozen

  • - talk about work! From what I've read pectin is released during the blanching at certain temperatures. Also the blanching removes some external starches, which I assume rinsing and soaking may accomplish. Plus if you blanch in salted water you pre-salt the fries. My question is, what does that initial lower temperature fry do? Cook the inside? Why should I do it instead of just blanching and frying once? The accepted answer to this question says the initial fry is to cook the fries, which it seems blanching already does. It seems to have something to do with starch molecules

  • . I'm curious because I'd like to look up similar recipes to get ideas on how to tweak it. We've always called it "goulash", but it doesn't look like the goulashes I've seen on the net. (Sorry about.... Dumplings some flour some milk Mix together in proportions that make it good and gloppy. You dont want dough, or soup. When the soup is nearly done, drop large spoonfuls into the boiling soup.... Put a few big spoonfuls of cucumber salad into it. Eat it and smile. So, what the heck have I been cooking?

  • OK, so I'm trying to make fudge. The recipe which I'm following doesn't give all that much in the way of directions. So I'd like clarification of a few points, so I know what I'm aiming for. Am I..., but obviously I'd like to try some other things - if I ever get the fudge itself to work...) I guess that's quite a lot of points for just one question, but I think it shouldn't be too hard to answer them all... ask), and then stop heating it and let it cool down again. (?) How crucial is it that it's exactly 116°C? I mean, obviously if it was way hotter or colder, that would be bad. But what kind of tolerance

  • Based on a related question, some of us are curious about surface tension in liquids commonly used in food and drink. There's a table on Wikipedia containing a tantalizing amount of information... effects on surface tension? Especially interesting would be ones without flavor, which could be used to tweak existing liquids. Note: I posted a related question on the physics stackexchange. ... surface tension than water, 76 mN/m at 20C. Very salty water (6M, compared to seawater at .6M) has higher surface tension, 83 mN/m at 20C. Of interest would be: How does surface tension typically

  • . So would rather like this question to border on food chemistry or industrial espionage. (Most likely the solution is some food additive though..) So what's the magic behind Kaba or Nesquik? How do... (can't find link) read somewhere about steam (hot water) playing a role in turning cocoa powder into instant granules. But also obviously, I'm looking for something you can do in an ordinary kitchen... of mixing it with cold fluids. - So I went out and bought some strongly de-oiled cocoa, which subjectively mixes better already. (But that might be just post-purchase rationalization.) Adding glucose powder

Data information