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Came across this hack for using ordinary liquid soap in dishwasher. Posting it here since a hack is a hack :) tldr: use a few tablespoons of baking soda with t

Came across this hack for using ordinary liquid soap in dishwasher. Posting it here since a hack is a hack :) tldr: use a few tablespoons of baking soda with the regular dishwash soap. The reason for not being able to use regular dishwash soap is because it makes lots of suds which floods your dishwasher. But baking soda prevents that from happening. Would love to know the pros and cons from an expert here.

Domenic_S 6y ago
that is literally what the article says to do
- giarc 6y ago
  To be fair, it takes about 4 paragraphs for the author to get to that point.
- jccc 6y ago
  Commenter is the submitter. Often someone will submit a post, and then add the first comment.
refurb 6y ago
I was a chemist in my past life, but not a soap chemist, so no doubt someone will be along to correct me. At a high level, soap is soap. They are basically molecules with a greasy end (long carbon chain) and a polar end (ionic group). The molecules form stable micelles that looks like little cell membranes almost, with the greasy ends pointing inward and the polar ends pointing outward (in contact with water, which is polar). That allows the soap to combine with greasy molecules you are trying to clean away. You're basically suspending the grease in water using the soap molecules. Now, there are a ton of different soap though. The polar functional groups can be carboxylic acids (typical homemade soap, hydrolyze fats with lye), or phosphate groups (now banned as the phosphates end up in waterways and cause algae blooms) or sulfates (the most typical last time I looked). There are no doubt others I'm not as familiar with. Now soaps all do the same thing, but there are important differences. So this "hack" works in terms of providing a soap and killing the foaming with baking soda (we used this trick in the lab all the time to break up foams and emulsions). The baking soda can also act as a water softening agent. That said, dishwashers are usually made for specific detergents because you don't want build up from leftover soaps and you also don't want to corrode any metal parts. So this works, but probably not as good as actual dish detergent (but it might not matter if your dishes aren't that dirty), but you are taking a risk that continued use might gunk up your machine. Or maybe it won't.
- pedantsamaritan 6y ago
  I think most dishwasher detergents switched to enzymes to replace phosphates: https://www.cnet.com/news/appliance-science-how-dishwasher-detergents-digest-food-stains/ https://www.cnet.com/news/appliance-science-how-dishwasher-d... That article implies the enzymes do some work, so that surfactants/soap can carry away the tougher components (protein and starch)
  - Scoundreller 6y ago
    I could believe the enzyme bit. Soaps require 3 things to work well: sheer force, concentration and temperature. The higher the better for all 3. Dishwashers can’t do consistent sheer force unless the sprayer hits your dish just right. So makes sense that their cleaning agent will use some other mechanism just requiring application/soaking and not sheer force.
    - twic 6y ago
      Dishwasher powder is also extremely alkaline, i believe. I (cosmetically) ruined an aluminium Moka coffee pot by putting it through a dishwasher.
      - refurb 6y ago
        Nothing cleans quite as good as strong alkaline. In the lab, we'd use a 50% lye bath and it strips off everything. If you want to add a bit of punch, you can add some 30% hydrogen peroxide as an oxidizer. Caution is needed as mixing a strong oxidizer and organic material is a recipe for fire or an explosion.
        Scoundreller 6y ago
        Yah, lye won’t just clean, but also help make new soap from anything fatty!
        rstuart4133 6y ago
        > Nothing cleans quite as good as strong alkaline. Depends on what you are cleaning. Most oven cleaners are strong alkalines, often sodium hydroxide. They work well enough on grease, but neglect it a bit and the heat turns the grease into a char that nothing short of a steel scraper and lot of elbow grease will remove. (On reflection, that char may be a combination of what was grease and protein.) In any case, alkaline cleaners and soaps won't touch it. But allow to ammonia at it for 12 or so hours (it doesn't have to be wet - just exposed), and it just wipes away. The usual technique is to put the stainless steel fittings in a garbage bag, pour in a cup of cloudy ammonia, and tie off overnight. (If you want to have working nostrils afterwards, open bag outside.) It even works on the glass door. Open so it's flat, cover with paper towels, soak paper towels in cloudy ammonia, hide outside for an hour so the smell doesn't take you out and burnt on crap wipes off. I don't the chemistry is, but it's magic. It would be interesting to find out what the chemistry is, actually.
reaperducer 6y ago
The reason for not being able to use regular dishwash soap is because it makes lots of suds which floods your dishwasher. And by "floods your dishwasher" he means "makes enough suds that they escape from the bottom of the dishwasher door and spread themselves across the entire kitchen in a giant soapy mess. Found this out when my grandmother, who had never seen a dishwasher before and had no concept of "dishwasher detergent," came to stay for a while.
analog31 6y ago
An additional function of the powdered detergent is that it's an abrasive, so it helps scour the dishes.

Domenic_S 6y ago

that is literally what the article says to do

giarc 6y ago
To be fair, it takes about 4 paragraphs for the author to get to that point.
jccc 6y ago
Commenter is the submitter. Often someone will submit a post, and then add the first comment.

refurb 6y ago

I was a chemist in my past life, but not a soap chemist, so no doubt someone will be along to correct me. At a high level, soap is soap. They are basically molecules with a greasy end (long carbon chain) and a polar end (ionic group). The molecules form stable micelles that looks like little cell membranes almost, with the greasy ends pointing inward and the polar ends pointing outward (in contact with water, which is polar). That allows the soap to combine with greasy molecules you are trying to clean away. You're basically suspending the grease in water using the soap molecules. Now, there are a ton of different soap though. The polar functional groups can be carboxylic acids (typical homemade soap, hydrolyze fats with lye), or phosphate groups (now banned as the phosphates end up in waterways and cause algae blooms) or sulfates (the most typical last time I looked). There are no doubt others I'm not as familiar with. Now soaps all do the same thing, but there are important differences. So this "hack" works in terms of providing a soap and killing the foaming with baking soda (we used this trick in the lab all the time to break up foams and emulsions). The baking soda can also act as a water softening agent. That said, dishwashers are usually made for specific detergents because you don't want build up from leftover soaps and you also don't want to corrode any metal parts. So this works, but probably not as good as actual dish detergent (but it might not matter if your dishes aren't that dirty), but you are taking a risk that continued use might gunk up your machine. Or maybe it won't.

pedantsamaritan 6y ago
I think most dishwasher detergents switched to enzymes to replace phosphates: https://www.cnet.com/news/appliance-science-how-dishwasher-detergents-digest-food-stains/ https://www.cnet.com/news/appliance-science-how-dishwasher-d... That article implies the enzymes do some work, so that surfactants/soap can carry away the tougher components (protein and starch)
- Scoundreller 6y ago
  I could believe the enzyme bit. Soaps require 3 things to work well: sheer force, concentration and temperature. The higher the better for all 3. Dishwashers can’t do consistent sheer force unless the sprayer hits your dish just right. So makes sense that their cleaning agent will use some other mechanism just requiring application/soaking and not sheer force.
  - twic 6y ago
    Dishwasher powder is also extremely alkaline, i believe. I (cosmetically) ruined an aluminium Moka coffee pot by putting it through a dishwasher.
    - refurb 6y ago
      Nothing cleans quite as good as strong alkaline. In the lab, we'd use a 50% lye bath and it strips off everything. If you want to add a bit of punch, you can add some 30% hydrogen peroxide as an oxidizer. Caution is needed as mixing a strong oxidizer and organic material is a recipe for fire or an explosion.
      - Scoundreller 6y ago
        Yah, lye won’t just clean, but also help make new soap from anything fatty!
      - rstuart4133 6y ago
        > Nothing cleans quite as good as strong alkaline. Depends on what you are cleaning. Most oven cleaners are strong alkalines, often sodium hydroxide. They work well enough on grease, but neglect it a bit and the heat turns the grease into a char that nothing short of a steel scraper and lot of elbow grease will remove. (On reflection, that char may be a combination of what was grease and protein.) In any case, alkaline cleaners and soaps won't touch it. But allow to ammonia at it for 12 or so hours (it doesn't have to be wet - just exposed), and it just wipes away. The usual technique is to put the stainless steel fittings in a garbage bag, pour in a cup of cloudy ammonia, and tie off overnight. (If you want to have working nostrils afterwards, open bag outside.) It even works on the glass door. Open so it's flat, cover with paper towels, soak paper towels in cloudy ammonia, hide outside for an hour so the smell doesn't take you out and burnt on crap wipes off. I don't the chemistry is, but it's magic. It would be interesting to find out what the chemistry is, actually.

reaperducer 6y ago

The reason for not being able to use regular dishwash soap is because it makes lots of suds which floods your dishwasher. And by "floods your dishwasher" he means "makes enough suds that they escape from the bottom of the dishwasher door and spread themselves across the entire kitchen in a giant soapy mess. Found this out when my grandmother, who had never seen a dishwasher before and had no concept of "dishwasher detergent," came to stay for a while.

analog31 6y ago

An additional function of the powdered detergent is that it's an abrasive, so it helps scour the dishes.