# Happy Easter What is ALUM? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [April 8, 2012, 5:49am UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157 "2012-04-08T05:49:54Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![cynyc](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@cynyc](https://boards.straightdope.com/u/cynyc)\ **Post date:** [April 8, 2012, 5:49am UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/1 "2012-04-08T05:49:54Z")
HOW TO WRITE UNDER THE SHELL OF AN EGG Dissolve one ounce of Alum in a half pint of Vinegar. Use a small pointed brush to outline whatever design or write whatever words you want on the shell of an egg. After the solution has dried out thoroughly on the egg, boil it for about 15 minutes. If you follow these directions the design will disappear from the outside of the shell but the writing will plainly show on the white of the egg when you remove the shell. Keep the messages short and have a ball. ---
**Author:** ![Alan\_Smithee](https://avatars.discourse-cdn.com/v4/letter/a/2acd7d/32.png) [@Alan\_Smithee](https://boards.straightdope.com/u/Alan_Smithee)\ **Post date:** [April 8, 2012, 5:58am UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/2 "2012-04-08T05:58:24Z")
It’s the stuff that made Tom’s mouth pucker up so that he had to suck Jerry up through a straw! Seriously, it’s a chemical used as (among other things) a preservative in pickling. Supposedly, you can find it in the spice section of a grocery store. If that doesn’t work, it’s also what those “Thai deoderant crystals” are made of. ---
**Author:** ![Inner\_Stickler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inner_stickler/32/318_2.png) [@Inner\_Stickler](https://boards.straightdope.com/u/Inner_Stickler)\ **Post date:** [April 8, 2012, 5:59am UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/3 "2012-04-08T05:59:09Z")
It’s a white powder. I used it once when I was in elementary school to grow crystals. They were underwhelming. Try looking in the grocery store. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [April 8, 2012, 7:16am UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/4 "2012-04-08T07:16:06Z")
Chemically, it’s potassium aluminium sulphate dodecahydrate, KAl(SO[sub]4[/sub])[sub]2[/sub].12H[sub]2[/sub]O. The water is “water of crystallisation” and can be boiled off (that’s not uncommon; copper sulphate’s another common example). I have a styptic pencil that I sometimes use for shaving cuts; that’s basically a stick of alum. ---
**Author:** ![Monty](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/monty/32/47_2.png) [@Monty](https://boards.straightdope.com/u/Monty)\ **Post date:** [April 8, 2012, 8:49am UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/5 "2012-04-08T08:49:18Z")
When I lived in Davis, California, I ordered alum through a pharmacy. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [April 8, 2012, 9:12am UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/6 "2012-04-08T09:12:35Z")
> [@](#): > > Happy Easter What is ALUM? These Easter carols are just getting weirder and weirder. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [April 8, 2012, 4:22pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/7 "2012-04-08T16:22:33Z")
I second the recommendation to look in the spice aisle of your grocery store. McCormick sells it in small squat plastic jars of 1.9 ounces. I pay $3 or $4. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [April 8, 2012, 5:35pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/8 "2012-04-08T17:35:48Z")
> [@Derleth](#): > > These Easter carols are just getting weirder and weirder. “Happy Easter, what is alum? / Potassium aluminum sulphate” actually works to the tune of “Christ the Lord is risen today”, though the stresses are in weird places in the chemical name. ---
**Author:** ![cynyc](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@cynyc](https://boards.straightdope.com/u/cynyc)\ **Post date:** [April 8, 2012, 6:14pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/9 "2012-04-08T18:14:09Z")
Re the styptic pencil: Halleluiah! ---
**Author:** ![freckafree](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/freckafree/32/3050_2.png) [@freckafree](https://boards.straightdope.com/u/freckafree)\ **Post date:** [April 8, 2012, 6:33pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/10 "2012-04-08T18:33:20Z")
> [@Alan\_Smithee](#): > > It’s the stuff that made Tom’s mouth pucker up so that he had to suck Jerry up through a straw! This. When I was a kid, if any of us said something hateful, mean, dirty, or otherwise objectionable, Mom would threaten to get out the can of alum. ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [April 8, 2012, 7:51pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/11 "2012-04-08T19:51:29Z")
If the supposed General Question is “What is Alum,?” then searching on Google/Wikipedia would be more appropriate. If there wasn’t truly such a question, then I’ve moved it to MPSIMS, to which it is more suited. **samclem** , MOderator ---
**Author:** ![ducati](https://avatars.discourse-cdn.com/v4/letter/d/cc9497/32.png) [@ducati](https://boards.straightdope.com/u/ducati)\ **Post date:** [April 9, 2012, 5:13pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/12 "2012-04-09T17:13:42Z")
I am so doing this the next event that requires boiled eggs. July picnics, Thanksgiving, Easter - you name it. I can’t think of a better way to terrorize my nieces and nephews: You will die today REDRUM Put me down Don’t eat me, Grant Look behind you! Brush your teeth Who has better suggestions to scare the bejeebus out of picnickers and holiday guests? ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [April 9, 2012, 7:28pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/13 "2012-04-09T19:28:15Z")
Or !EREH NI PEDDART M’I !PLEH ---
**Author:** ![cynyc](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@cynyc](https://boards.straightdope.com/u/cynyc)\ **Post date:** [April 28, 2012, 8:04pm UTC](https://boards.straightdope.com/t/happy-easter-what-is-alum/618157/14 "2012-04-28T20:04:09Z")
Every year I lipstick RedruM on my door. Parents get a kick out of it. But this isn’t why I came back… The guy who told me the egg trick is a Vietnam veteran. He said the prostitutes over there used gobs of the stuff in themselves with bowls of it next to their beds. He thinks it was for tightening. I don’t know. FWIW. > [@ducati](#): > > I am so doing this the next event that requires boiled eggs. July picnics, Thanksgiving, Easter - you name it. > > I can’t think of a better way to terrorize my nieces and nephews: > > You will die today > REDRUM > Put me down > Don’t eat me, Grant > Look behind you! > Brush your teeth > > Who has better suggestions to scare the bejeebus out of picnickers and holiday guests?