When a potato cooks, the starches contained in each cell are released as the cell walls break down. These starches absorb the potato’s internal moisture and swell and soften. These two processes are what transform a raw, hard potato into a cooked, softer potato fit for mashing.
If you cut your potatoes up before boiling them, the starches absorb the internal potato moisture as well as the water in which they’re being boiled. If they boil for too long, they absorb too much water and your mashed potatoes will become gummy. The difference between perfectly cooked potato pieces and soggy pieces can sometimes be as little as a minute or two.
An easy workaround is to boil potatoes whole. They’ll take a bit longer to cook but you can leave them in the hot water after boiling without undesirable effects, keeping them warm until it’s time to mash them. I start my potatoes boiling as soon as I begin cooking and mash them immediately before dinner.
If they need more moisture, you can add a bit of hot potato boiling water or another liquid. This way, you have more control of their moisture content.
Just to preface, I’m actively trying to not be the “well, ackshally” guy. I’m just really passionate about potatoes and potato education. Really just science education but potatoes are science, dammit.
The part you quoted, when in the context of the rest of the post, describes how boiling them whole specifically allows you to leave them in the pot without them getting soggy. You can leave them in there for an extended length of time as the amount of water they’ll absorb relative to their total volume is minimal due to the low surface area to volume ratio, plus the intact skin severely reduces the rate of water absorption.
Here’s where the well ackshally avoidance part is important. I have an MSc in botany, so I took a lot of plant physiology courses, plus I wrote a paper about this as a “fuck you” response to a stupid assignment by an asshole professor. The following is a crash course on potato science, no one is under no obligation to read it.
It’s not overcooking itself that causes soggy taters. When you cook a potato, the starch absorbs water and swells. When you cook a whole potato, the amount of water available is rather limited as potatoes are low moisture tubers, so the starch can only absorb as much water as is available in the tater itself. When boiled whole, the periderm (skin) maintains the structure of the potato, keeping it from breaking apart, and limits the amount of water that can be absorbed into the pith, the starchy interior. The latter is actually one of the primary natural functions of the skin. The total moisture content of a boiled whole potato is shockingly close to its raw state. Don’t believe me? Weigh a few whole taters using a decent scale, boil them for an hour, then weigh them again. It’ll be damn near the same. That’s one of the perks of cooking them my way - I can add more milk and butter without them getting soggy.
When you cut potatoes up, the starch can maximally swell as it has practically unlimited access to water, plus vastly more surface area, increasing the rate of water absorbtion. Since the skin no longer maintains the shape of the potato, small fissures appear as the structure of the pith begins to degrade. These further increase the surface area, consequently increasing water absorbtion even more, which further increases pith degradation. It’s this excessive water absorption by starch that leads to a gluey consistency and being cut up facilitates absorbtion through these mechanisms. This is also why wax potatoes are more resistant to falling apart than floury potatoes when boiled, as the starch content of a wax potato is much lower. Side note: I actually prefer a 1:1 ratio of wax to floury potatoes in my mash.
A way to test and verify is to boil up some spuds using your preferred method and mash them as normal, but add a fair bit more than normal of hot water, milk, or another primarily water based liquid, i.e., not cream or butter. You’ll end up with a gluey tater paste.
I love you for this.
Aww, thanks! It’s by far the most Lemmy thing I’ve ever done.
Wow, awesome. Thank you!
Your explanation of why you make sous vide mashed potatoes because you can’t handle a 10 minute cooking time is hilarious, thanks.
Imagine being the kind of person that, presumably as an adult, you think it’s cool to mock people on the Internet. I hope that made you feel better about yourself.
Edit: JFC, you’re the original comment guy, AKA the quintessential “well, ackshally” ex-Redditor. You’re just upset because I pointed out that you can’t read, then you proved it a second time.
I understand the original post, it was presented as a solution to a non-existent problem instead of just an alternate method.
I now see my mistake: I made a post that addresses a problem that you’ve never had and failed to remember that the world is no greater than your experience. I clearly am the worst kind of person and deserve your criticism.
My thanks also for your public service of mocking people trying to be helpful or educational on the Internet. You truly exemplify how actions taken by those in anonymity speak volumes of their character.
How much does being a professional victim pay per year, and does it require a lot of overtime?
You are massively overreacting to some constructive criticism followed by some lighthearted humor. Learn to laugh at yourself a little.
Ahhh, the old “I offended someone on the Internet when I made fun of them, so I made fun of them again then blamed them for all it when they said something”.
At first I figured you were just being an asshole. It happens, people have bad days or phrase things poorly. Then you proved you weren’t just being an asshole - you actually ARE an asshole.