# Tomatoes stop beans/quinoa from absorbing water? **URL:** \ **Category:** Cafe Society\ **Created:** [April 18, 2019, 9:41pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741 "2019-04-18T21:41:58Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [April 18, 2019, 9:41pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/1 "2019-04-18T21:41:58Z")
I learned the hard way about tomatoes and beans a couple of weeks ago. Not wanting them to get too mushy, I added the beans into the crock pot with the tomatoes and other ingredients when they were about 3/4 cooked. I then proceeded to cook them for twelve hours, adding water occasionally. When I tasted them the next morning, they were delicious, but still only 3/4 cooked. So I moved them to the pressure cooker and gave them 20 minutes on high pressure. Maybe a skosh of improvement there, but mainly just 3/4 cooked. I’ve also had a long-running question about a quinoa casserole that stayed hard and gritty after plenty of time and added water as well. So, what is it about tomatoes that prevents beans (and quinoa?) from absorbing any more water? ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [April 18, 2019, 9:55pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/2 "2019-04-18T21:55:17Z")
According to the Michigan Bean Commission: > [@](#): > > When soaking and cooking dry beans, resist the urge to add anything other than fresh, cold water. Salt and acidic ingredients like tomatoes, citrus juice, vinegar, wine, or mustard inhibit the absorption of liquid and stop the softening process. Once hardening agents are added, the bean will not soften any further. Also, make sure to increase soaking and cooking times when using hard water. [http://michiganbean.org/cooking-tips/](http://michiganbean.org/cooking-tips/) ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [April 18, 2019, 10:23pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/3 "2019-04-18T22:23:46Z")
Salt is fine. I soak my beans all the time in salted water, and it works a treat to season them. [Cite](https://www.seriouseats.com/2016/09/salt-beans-cooking-soaking-water-good-or-bad.html): > [@](#): > > For the best, creamiest, most flavorful beans, season your bean-soaking water with one tablespoon of kosher salt per quart (about 15 grams per liter), rinse the beans with fresh water before cooking, then add a pinch of salt to the cooking water as well. As for tomatoes, I’ve never noticed a difference myself. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [April 18, 2019, 10:29pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/4 "2019-04-18T22:29:46Z")
> [@pulykamell](#): > > As for tomatoes, I’ve never noticed a difference myself. I should say this is for pre-soaked beans. For cooking from dry, I don’t know. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [April 18, 2019, 11:20pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/5 "2019-04-18T23:20:46Z")
Yeah I should note that there’s a lot of conflicting info out there. Some sites said the acid thing is a myth, others agreed with the Michigan Bean Commission. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 19, 2019, 3:25pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/6 "2019-04-19T15:25:21Z")
[Moderating] Since this is about cooking, let’s move it over to Cafe Society. ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [April 19, 2019, 3:40pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/7 "2019-04-19T15:40:25Z")
ATK did this. Acid is the villain. Salt your water for dried beans, but don’t add any acidic ingredients until they are already cooked. ---
**Author:** ![CairoCarol](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cairocarol/32/3825_2.png) [@CairoCarol](https://boards.straightdope.com/u/CairoCarol)\ **Post date:** [April 19, 2019, 4:06pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/8 "2019-04-19T16:06:37Z")
According to the book “Salt, Fat, Acid, Heat” by Samin Nosrat, salt is okay for cooking beans, but stay away from acid. Having had an unfortunate cooking episode with tomato paste and uncooked beans back when I was a poor student and couldn’t afford extra money on food, I have been wary of adding anything to my beans before they were fully cooked ever since. I believe Samin Nosrat (the book is awesome, I highly recommend it) but still can’t bring myself to add salt to beans during the cooking process. ---
**Author:** ![teela\_brown](https://avatars.discourse-cdn.com/v4/letter/t/d9b06d/32.png) [@teela\_brown](https://boards.straightdope.com/u/teela_brown)\ **Post date:** [April 19, 2019, 4:55pm UTC](https://boards.straightdope.com/t/tomatoes-stop-beans-quinoa-from-absorbing-water/832741/9 "2019-04-19T16:55:21Z")
There’s another factor: when dried beans start getting old, they don’t absorb water and remain half-uncooked. I once tried for three hours to get some split peas to soften up in plain old boiling water, but they were still partially firm. Then I read the sell-by on the bag and discovered that they were three years old. Yeah, America’s Test Kitchen tested out the theory that salt causes beans to not get tender, but they discovered that it just wasn’t true. Acid, however, does cause this effect. I trust their empirical approach.