Why is Dr Bronner Baby Mild so soft

[kchaystack]

PLus there is a kind of built in lye discount depending on the purity of your KOH. When you get it from the supplier is 90 - 95% pure. As you expose it to air, the CO2 and water in the air will lower this somewhat.

Also make sure you are using a soap calc that takes the purity of the caustic into account. Other wise it will assume it is 100% pure and that will cause you to have too much oil unreacted.

 

[topofmurrayhill]

Not necessarily asking because I want to make it more mild, just to be extra sure people don't get exposed to any excess KOH. Since we're on a Bronner's thread, this is how their label looks like, and I intend to shamelessly steal the bold bit :mrgreen::

Ingredients: bla*, bla* bla*, Potassium Hydroxide**, bla bla
*Certified organic ingredient
** None remains in the final product.

And I suppose the only true way to be sure that statement is true, given the fluctuation of oil properties and KOH concentration, is to acidify down to a certain level where you are 100% there isn't possible to have any leftover KOH. I think the limit to avoid having to do microbiology tests on the soap is a pH equal or above 9.5 (will ask and make sure soon). Bronners has a pH of 8.9, just for comparisson. Apparently shelf life isn't affected all that much by the process, given that it has the "usable for at least 36 months after being opened" logo thing on it.

I would recommend a 2% lye discount unless you know enough about your materials to be more precise. If you are really, really serious about quality control, you have to get Scientific Soapmaking and invest in learning some analytical techniques to test your oils and caustic. I would be very impressed with any seller who took their craft so seriously, but it's optional.

Some folks ascribe some sort of hi-tech magic to lye calculators just because simple arithmetic is programmed into a computer, so a 2% lye discount automagically means a 2% superfat. However, particularly considering that the purity of KOH easily varies in a 10 point range, if you estimate 90% purity and use a 2 or 3 percent lye discount, you can't be SURE of anything if you're concerned as a seller. In that respect, some test strips certainly wouldn't hurt.

The question you are getting at is whether it might be of value to perform an adjustment on every batch of soap to be absolutely certain. I think it might be overkill. It is probably sufficient to determine the normal pH for a particular recipe, so that you only need to be concerned if you get something out of the ordinary.

 

[Sapo]

1. Been meaning to get that book for a while for that precise reason, how I wish there was an e-book!

2. Exactly.

3. Thanks, needed a second input on the idea and you are probably right. Nevertheless, I shall obtain that book and learn more.

 

[topofmurrayhill]

PLus there is a kind of built in lye discount depending on the purity of your KOH. When you get it from the supplier is 90 - 95% pure. As you expose it to air, the CO2 and water in the air will lower this somewhat.

The common grades vary from 85% to 95%. I generally just go with 90%. Considering the wide range, you need to have a whole lot of faith in what your suppliers says you should assume. Do they know what they're talking about? Did they test it analytically?

To suggest that there is some procedure that lets you be certain that as a seller to the public your batches are coming out correctly and consistently without any analysis beyond tasting the soap, that's not really supportable. To say that it's a total waste for a seller to the public to buy a box of test strips if they want to and keep an eye on how their batches read, that's not really reasonable.

I'm not suggesting that you mean to say those things, but I think some might.

 

[Susie]

Are you implying that zap testing, AKA (according to you) "tasting" is a useless test?

I have never said it is useless for someone to test their soap, only that test strips are not reliable. Indeed, I have repeatedly stated that people intending to sell their soap should purchase a pH meter that is able to be calibrated and test it that way to ensure proper pH for preservatives. A pH meter is not that expensive, and is much more economical over the long haul than repeatedly purchasing strips. Or are you implying that test strips are more reliable than a properly calibrated meter?

 

[topofmurrayhill]

Are you implying that zap testing, AKA (according to you) "tasting" is a useless test?

No.

I have never said it is useless for someone to test their soap, only that test strips are not reliable. Indeed, I have repeatedly stated that people intending to sell their soap should purchase a pH meter that is able to be calibrated and test it that way to ensure proper pH for preservatives. A pH meter is not that expensive, and is much more economical over the long haul than repeatedly purchasing strips. Or are you implying that test strips are more reliable than a properly calibrated meter?

I'm not implying anything. Whatever I said is what I meant, no more and no less. We have discussed in this thread which strips work well with soap, and those are useful so I recommend them. As for your point about forgoing strips in favor of pH meters, I think one of our chemist regulars offered you feedback on that in another thread and was not wholly sympathetic. I don't find the need for it myself because it's kind of overkill and involves more money and hassle to get good readings to accomplish what I can already do. But of course I would be interested to hear about your experiences with Macherey-Nagel pH strips versus pH meters.

 

[Sapo]

Not saying this because he can't fight his own "battles", saying this because there seems to be a communication malfunction/misunderstanding between you two.

As I understand it, he said:

"Complete reliance on soap calculators for consistency of product, given the inherent fluctuations of the raw materials used, isn't supportable advice. Zap tests and pH strips are good indicators that something might have gone wrong."

His words regarding efficacy of pH strips: "Yep, I have only used the Macherey-Nagel strips and they have no problem with soap. Kevin Dunn recommends pH strips for anyone who doesn't wan't to zap test. For anyone who's interested in the pH of their liquid soap, I guess those are the ones to get."

No mention of zap testing being useless, no mention of pH strips being reliable or unreliable (but a mention of success with a particular brand, shared experience with IL), no comparisson between strips and meters.

Not sure where you got all that from .

Edit: he beat me to it.
Edit2: "he" may be a "she".

 

[dschiavo]

Sounds good do you care to share?

sure! 41 oz EVOO, 5 oz CO , 10 oz KOH/30 oz water, I use a 33% borax solution at dilution