# Alum pickles **URL:** \ **Category:** Factual Questions\ **Created:** [July 28, 2003, 3:28am UTC](https://boards.straightdope.com/t/alum-pickles/191367 "2003-07-28T03:28:32Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\ **Post date:** [July 28, 2003, 3:28am UTC](https://boards.straightdope.com/t/alum-pickles/191367/1 "2003-07-28T03:28:32Z")
My mother in law makes the best sweet pickles. Right now 3 crocks full of cucumbers are soaking in a saltwater brine. I don’t know the rest of the process but they are alum pickles. the alum is what makes them crisp. A quick google check says alum isn’t needed in pickle making anymore. I’m not going to argue with perfection but the alum raises a question. Isn’t alum just powdered aluminum? That really makes me wonder about the aluminum alzimers connection. I know a lot of pickle eaters but not many alzimer patients. So do they ask alzimers patients about their favorite pickles? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [July 28, 2003, 3:35am UTC](https://boards.straightdope.com/t/alum-pickles/191367/2 "2003-07-28T03:35:16Z")
Alum is aluminum sulfate. It’s an astringent, which means it dries stuff up, which is why styptic pencils are made out of it. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [July 28, 2003, 4:11am UTC](https://boards.straightdope.com/t/alum-pickles/191367/3 "2003-07-28T04:11:09Z")
Al[sup]3+[/sup] ions make quite an effective protein denaturing agent. When used in pickling, it serves to coagulate the outer layer of the pickle, and make it crunchy. The process is irreversible, so, as with the calcium hydroxide (lime) treatment, there’s no need to leave alum in the final canning brine. The pickles will stay crunchy even after rinsing and re-brining. ---
**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:** [July 28, 2003, 11:58am UTC](https://boards.straightdope.com/t/alum-pickles/191367/4 "2003-07-28T11:58:31Z")
Straight Dope Staff Report on [What is alum, and will it make someone’s mouth shrink, like in the cartoons?](http://www.straightdope.com/mailbag/malum.html)