# Thanksgiving + Sweet Potatoes + Cold Water = confusion **URL:** \ **Category:** Factual Questions\ **Created:** [December 1, 2005, 2:46pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555 "2005-12-01T14:46:29Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Frumpy\_Jones](https://avatars.discourse-cdn.com/v4/letter/f/da6949/32.png) [@Frumpy\_Jones](https://boards.straightdope.com/u/Frumpy_Jones)\ **Post date:** [December 1, 2005, 2:46pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/1 "2005-12-01T14:46:29Z")
I was over my parents for Thanksgiving and was going to make a Sweet Potato (SP) casserole. I filled up the pot with water to boil the potatoes, when my mom came out into the kitchen. I had dropped one SP into the water and turned on the heat. My mom did a **complete** freak out on me, scooped the potato out like it was a drowning baby, then dumped the big pot of water into the sink. I asked her what the hell just happened and she said > [@](#): > > you never put potatoes in hot water… Always cold. Indeed I had filled the pot with Hot water from the tap. I asked her what the difference was, as I am just going to boil everything anyway. She could not give me a reason other than that’s what she was taught. I even asked her if she ever USED hot water and had something happen to her potatoes… but she had not. I tried to think of a reason for why you shouldn’t use hot water, couldn’t come up with one, and told her I thought she was nutzo. She insisted that she was right, though nobody could think of a reason why she should or could be. So, TM’s, help me out here. Is there any actual reason to not put potatoes (or SP’s) in hot water before boiling??? ---
**Author:** ![norinew](https://avatars.discourse-cdn.com/v4/letter/n/eb9ed0/32.png) [@norinew](https://boards.straightdope.com/u/norinew)\ **Post date:** [December 1, 2005, 3:04pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/2 "2005-12-01T15:04:17Z")
Here’s what I’ve been told about white potatoes, which may have some bearing on what your mother’s talking about: put the potatoes in cold water, and then put them on the stove to boil, instead of letting the water get close to boiling and then adding your potatoes. This will result in fluffy, not gluey, mashed potatoes. The reason is that soaking them in water before boiling them will soak out some of the starch. So starting the water from cold gives the same effect as pre-soaking. Perhaps your mom has real-world experience with boiling sweet potatoes, or maybe she’s just extrapolated this to all potatoes, but it’s probably close to what she meant. Just FYI, I _never_ boil sweet potatoes for use in recipes, I bake them. IMHO, they have a better texture that way. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [December 1, 2005, 3:24pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/3 "2005-12-01T15:24:29Z")
[FWIW](http://www.porkpeople.com/accompot_kitchen.html) > [@](#): > > If potatoes were to be placed in hot or boiling water the outsides would be cooked before heat has the time to be conducted to their interior. This would result in the outsides being cooked when the insides were still raw. Most cooks are probably familiar with this phenomenon; the potatoes’ skin starts to slough off, the first quarter inch or so of the potato’s flesh is over-cooked and crumbly. But when the interior is cut into, it is still in its raw state. I switched to the microwave for sweet taters years ago. 15 minutes with a bit of water and a handful of brown sugar. Then drain, and toss them in the oven for 20 with more sugar, some butter and _shudder_, marshmallows if you must. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [December 1, 2005, 3:46pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/4 "2005-12-01T15:46:55Z")
> [@norinew](#): > > . . .soaking them in water before boiling them will soak out some of the starch. So starting the water from cold gives the same effect as pre-soaking. Neglible starch leeches into the water from soaking potatoes. The reason usually given for this technique is that if you immerse the potatoes in already-boiling water, the outside will cook much more quickly than the inside. If you bring the potatoes and water to a boil together, the potato heats through more evenly. One folk-rule is “if it grows under the ground, start it in cold water.” However, I will see if I can find an authoritative answer on this. ---
**Author:** ![Zabali\_Clawbane](https://avatars.discourse-cdn.com/v4/letter/z/ecd19e/32.png) [@Zabali\_Clawbane](https://boards.straightdope.com/u/Zabali_Clawbane)\ **Post date:** [December 1, 2005, 3:49pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/5 "2005-12-01T15:49:06Z")
Soaking potatoes does make a difference when making french fries, and it also makes a difference with mashed potatoes too. Try making batches using the method, discard the soaking water and you’ll notice a difference. I don’t know if that applies to sweet potatoes or not though. ---
**Author:** ![Carnac\_the\_Magnificent](https://avatars.discourse-cdn.com/v4/letter/c/ccd318/32.png) [@Carnac\_the\_Magnificent](https://boards.straightdope.com/u/Carnac_the_Magnificent)\ **Post date:** [December 1, 2005, 4:14pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/6 "2005-12-01T16:14:18Z")
> [@Frumpy Jones](#): > > Is there any actual reason to not put potatoes (or SP’s) in hot water before boiling??? Possibly. During the ~ 2001 media frenzy over acrylamides, some authorities suggested tossing potatoes into boiling water, which presumably would get them through the hypothesized temperature danger zone more quickly and thereby reduce acrylamide production. More recent studies cast doubt and suggest acrylamide production is low for boiled potatoes anyway. But sky high for French/freedom fries and potato chips. The health consequences of all this, of course, is purely speculative, thus meriting an equally cautious “whatever.” ---
**Author:** ![irishgirl](https://avatars.discourse-cdn.com/v4/letter/i/8edcca/32.png) [@irishgirl](https://boards.straightdope.com/u/irishgirl)\ **Post date:** [December 1, 2005, 4:35pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/7 "2005-12-01T16:35:00Z")
My grandmother taught me the same thing. Anything that grows under the ground gets put in cold water, anything over the ground gets put into boiling water. My grandmother, however, also believes hot water from the tap is hazardous to human health (she grew up when water pipes had lead in them) so would go bananas if anyone used hot tap water in any kind of culinary exercise. ---
**Author:** ![Frumpy\_Jones](https://avatars.discourse-cdn.com/v4/letter/f/da6949/32.png) [@Frumpy\_Jones](https://boards.straightdope.com/u/Frumpy_Jones)\ **Post date:** [December 2, 2005, 12:43pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/8 "2005-12-02T12:43:22Z")
> [@Carnac the Magnificent!](#): > > Possibly. During the ~ 2001 media frenzy over acrylamides, some authorities suggested tossing potatoes into boiling water, which presumably would get them through the hypothesized temperature danger zone more quickly and thereby reduce acrylamide production. More recent studies cast doubt and suggest acrylamide production is low for boiled potatoes anyway. But sky high for French/freedom fries and potato chips. The health consequences of all this, of course, is purely speculative, thus meriting an equally cautious “whatever.” Well, my mom wasn’t talking about 2001. She’s 72. She’s talking about her mom and dad teaching her this in the 1940’s… I guess what I’m looking for is a more scientific reason for it, or what the science-bound basis of the quote “if it grows under ground, put it in cold water” actually is… ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [December 2, 2005, 12:55pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/9 "2005-12-02T12:55:14Z")
> [@CookingWithGas](#): > > Neglible starch leeches into the water from soaking potatoes. Are you sure about this? I regularly soak chopped potatoes in cold water for an hour before cooking, and a large amount of white stuff is visible in the liquid that I strain off. Anecdotally, doing this does seem to make a big difference to mashed and roast potatoes. ---
**Author:** ![Nimue](https://avatars.discourse-cdn.com/v4/letter/n/d26b3c/32.png) [@Nimue](https://boards.straightdope.com/u/Nimue)\ **Post date:** [December 2, 2005, 4:49pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/10 "2005-12-02T16:49:35Z")
FWIW, I too have been taught both a) to put potatoes into a pot of cold water before bringing it to a boil, and b) never to cook using hot tap water. I always assumed that the reason for “b” was because of either minerals (or other substances) in the water or possibly microorganisms living in the hot water tank or something. Potatoes are very starchy and probably benefit from being soaked/rinsed the same way that rice does. ---
**Author:** ![groman](https://avatars.discourse-cdn.com/v4/letter/g/73ab20/32.png) [@groman](https://boards.straightdope.com/u/groman)\ **Post date:** [December 2, 2005, 7:09pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/11 "2005-12-02T19:09:52Z")
A sidenote, but in Moscow, Russia for example, hot water is practically non-potable. Since the entire city has central water heating, the hot water is super-chlorinated and traveled great distances through a lot of pipes whilst hot - not something you want to drink or have absorbed into your food. Is there a chance beliefs such as this have something to do with immigrants not knowing that most american hot water in newer houses IS potable? ---
**Author:** ![rainy](https://avatars.discourse-cdn.com/v4/letter/r/c2a13f/32.png) [@rainy](https://boards.straightdope.com/u/rainy)\ **Post date:** [December 2, 2005, 7:21pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/12 "2005-12-02T19:21:20Z")
Also before PVC became the standard for home plumbing, the feed pipes were copper. Using hot tap water made the taste imparted by the copper to the water very noticeable 9and I would assume then also evident in the cooked food). My father was a plumber and always viewed the upgrade from roll copper to ‘tasteless’ plastic as well worth the time and expense. -rainy ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [December 2, 2005, 7:46pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/13 "2005-12-02T19:46:38Z")
> [@jjimm](#): > > Are you sure about this? I regularly soak chopped potatoes in cold water for an hour before cooking, and a large amount of white stuff is visible in the liquid that I strain off. Anecdotally, doing this does seem to make a big difference to mashed and roast potatoes. Some measurable amount from the surface of the potato may leech out, but negligible as a percentage. An [Idaho potato](http://radio.boisestate.edu/information/otherprojects/potato/nutrit.html) is around 15% starch by weight (it’s 15% carbs, I am assuming most of that is starch). You are not making a dent in that by soaking some out. Try this (come to think of it, I may try it). Soak 10 lbs of potatoes for as long as makes you happy. That represents about 1.5 lbs of starch. Remove the potatoes. Boil the pot dry. See how much starch is left. Weigh it if you have a lab scale. ---
**Author:** ![Carnac\_the\_Magnificent](https://avatars.discourse-cdn.com/v4/letter/c/ccd318/32.png) [@Carnac\_the\_Magnificent](https://boards.straightdope.com/u/Carnac_the_Magnificent)\ **Post date:** [December 2, 2005, 9:17pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/14 "2005-12-02T21:17:54Z")
> [@Frumpy Jones](#): > > Well, my mom wasn’t talking about 2001. She’s 72. She’s talking about her mom and dad teaching her this in the 1940’s… Your grandparents may possess mystical powers that you can’t begin to comprehend. ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [December 2, 2005, 10:16pm UTC](https://boards.straightdope.com/t/thanksgiving-sweet-potatoes-cold-water-confusion/333555/15 "2005-12-02T22:16:36Z")
> [@Frumpy Jones](#): > > I was over my parents for Thanksgiving and was going to make a Sweet Potato (SP) casserole. I filled up the pot with water to boil the potatoes, when my mom came out into the kitchen. I had dropped one SP into the water and turned on the heat. I apply a little olive or vegetable oil to the skin, put it in the mircroway or oven and bake SP’s! Come out smooth as silk.