Butyric acid smell using cow's milk

[jeanemarie]

This thread sort of continues ones from 2017 discussing baby vomit/cheesy smells in soap using cow's milk and one from 2020 discussing baking soda in soap. But I thought it best to just start a new thread.

I want to use powdered cream in an Oatmeal, Cream & Honey soap but I am concerned about getting that baby vomit/cheesy smell in the soap especially since I want to leave it unscented. It is caused by the higher level of butyric acid in cow's milk than goat's milk. But the benefits of milk sure look lovely.

Then I found that baking soda neutralizes butyric acid and removes the smell - in a Google search that had nothing to do with soap making. Pairing that with these comments from 2020 I am now eager to try mixing baking soda with my cow's milk (actually powdered cream).

Yes, I've tried it... long time ago... did NOT do it Old School though. I'm smarter than that! LOL I used Water, NaOH, Pomace OO & 1 tablespoon baking soda PPO. As I recall the baking soda bumped the lather and produced a mild soap good for sensitive skin. Nice.

You can use baking soda as an additive in soap, but baking soda will not actually saponify with fat unless it gets a LOT of encouragement. Typical hot or cold process methods don't work.

My questions are -
Does anyone have an idea as to how much I should add to the formula?
Should I stick with 1TBS PPO?
Should I reconstitute the powder with reserved water (I masterbatch lye) and add the baking soda to that before adding to the oils?
Thanks for any ideas, knowledge, jokes.....

The previous threads I read were -

Hello! Anyone know anything about olive-baking-soda-and-water soap?​

Is non-fat powdered milk good enough?​

 

[DeeAnna]

If the article you read is not related to soap making, I question whether it's valid to apply the info to soap making.

In a soap making context, I don't see how baking soda will do anything more to control the odor of butyric acid soap than sodium hydroxide would do. But I don't have experience with using baking soda as odor control in soap and I haven't read the article you mention, so this is purely my opinion without a lot of context.

Remember the total amount of butyric acid is also big factor. I've used whole milk and cream in soap. Frankly I haven't found the odor to be a problem because butyric acid is only a tiny portion of the total fatty acid in the soap.

It's when I've used butter as a large portion of the total fat that the odor was distinct to my nose.

In the future, it would be best to give a link to your sources so everyone is "on the same page." It handicaps the conversation if you expect the rest of us to guess about what you've read and how you're applying that information.

 

[lsg]

I have used reconstituted powdered milk, whole milk and cream in my soap with no problem. Any lingering odor usually dissipates in a few days. Adding baking soda to soap may make it misbehave.

 

[AliOop]

I have not gotten any bad smells from using any milks, yogurts, or creams making to make soap. Only butter and ghee give off that horrible vomit smell, no matter how long the soaps cure.

I should note that some folks get an ammonia smell when using frozen milks to dissolve the dry NaOH. The first-hand testimonies I’ve read all say that the ammonia smell dissipates within a week or so.

 

[artemis]

I use powdered buttermilk. I either mix the powder in with my oils before adding the lye solution, or I make a slurry of it with a little of my plain water and blend that into my oils before adding the lye solution. I have never noticed a smell.

 

[paradisi]

I use powdered buttermilk. I either mix the powder in with my oils before adding the lye solution, or I make a slurry of it with a little of my plain water and blend that into my oils before adding the lye solution. I have never noticed a smell.

Buttermilk is what's left after making butter from cream. Has the smelly part already removed.

 

[artemis]

Buttermilk is what's left after making butter from cream. Has the smelly part already removed.

Yes, but the initial question was about getting the benefits from cows milk without the smell...

 

[DeeAnna]

It's good to remember that butyric acid is only found in the milkfat (aka butterfat). It's not present in non-fat milk.

But again, cream and full-fat milk don't have enough butyric acid to create much of an odor in a batch of soap.

The problem starts when using butter (around 80-90% milkfat) or ghee (100% milkfat) as a main fat in the soap batch.

An ammonia smell is created when the lye reacts with protein -- all milk, even non-fat, contains protein. I've also gotten this ammonia odor when using eggs in soap. The ammonia odor might linger for a few days right after the soap is made, but dissipates fairly quickly.