Lye Calculators

[HobbyMom]

"*Please note: The Bramble Berry Lye Calculator assumes a 90% purity for Potassium Hydroxide (liquid soapmaking) and 97% purity for Sodium Hydroxide (solid bar soapmaking). These purity levels are what are commonly available for sale to consumers, including the lye sold at Bramble Berry"

>>>> My question is my lye is 100% Pure food grade. Do I need to consider that there could be added lye weight on my end due to the weight of the impurities in B.B. lye. OR will the smidgen of difference be okay?

 

[shunt2011]

I don't use BrambleBerry, I use Soapcalc.net or Soapee.com....but they all pretty much have their own assumption. Soapee allows you to adjust your purity. With that being said even food grade is not 100%. I use food grade and it still is allowed to have impurities. So, I just leave the rate as is in the calculator.

 

[DeeAnna]

Don't confuse purity with additives.

100% NaOH does not have ADDITIVES, meaning other chemicals intentionally added to the product by the manufacturer.

100% NaOH will always have IMPURITIES, meaning other chemicals that are naturally present in the product. NaOH always has impurities due to how its made and how easily it reacts with carbon dioxide and water. This is a normal thing. Commercial grades of NaOH are generally 95-97% NaOH, meaning 3-5% are impurities.

If you're buying food grade 100% NaOH from Essential Depot, you'll see this information about purity in their certificate of analysis. Last time I checked, I recall the purity was around 97%, give or take a bit. Look there if you don't believe me. If my recollection is correct, the BB calc should be fine.

 

[shunt2011]

I use Essential Depot and it's 97% the last time I checked.

 

[HobbyMom]

I use Essential Depot and it's 97% the last time I checked.

I bought the "Belle Chemical food grade pure 100% NaOH" from B.C. So I wasn't sure.

 

[shunt2011]

I bought the "Belle Chemical food grade pure 100% NaOH" from B.C. So I wasn't sure.

Still won't be 100%. So you should be fine just leaving the calculator where it is.

 

[HobbyMom]

I don't use BrambleBerry, I use Soapcalc.net or Soapee.com....but they all pretty much have their own assumption. Soapee allows you to adjust your purity. With that being said even food grade is not 100%. I use food grade and it still is allowed to have impurities. So, I just leave the rate as is in the calculator.

I have to use Brambleberry at first so I can learn to get use to using lye and making my first CP soaps since I am using the lots of lather bag of oils from there for right now.

Still won't be 100%. So you should be fine just leaving the calculator where it is.

Thanks for teaching me. I checked the B.C. website under questions and found this. So do I need to change anything on lye calculator... I don't understand.

"Can this be used for making soap?

• Yes and love to hear your soap making stories and pictures! If using this product for soap and using a soap calculator, use the 100% concentration lye."

 

[penelopejane]

No don’t change anything. You are overthinking it.

You can still use soap calc even if you buy your ingredients from brambleberry.

 

[HobbyMom]

No don’t change anything. You are overthinking it.

You can still use soap calc even if you buy your ingredients from brambleberry.

I proably am, I just don't want burn my skin. To be extra safe do you think using a 7% superfat setting would work okay?

 

[shunt2011]

You can up your SF a bit if it makes you more comfortable. They are not being honest. I would ask for their MSDS sheet. Lye is not 100% pure period. As DeeAnna stated above. You are overthinking something that's not an issue.

 

[DeeAnna]

I'm not sure why the supplier is giving this advice except as a "CYA" thing.

My personal soap calc includes a correction for purity. I've checked my NaOH and know it really is around 97% pure. I routinely use recipes with 3% superfat with a 97% purity setting for my NaOH. I've yet to make a lye-heavy soap yet with these numbers.

To give you some perspective -- If your soap recipe is set to 5% superfat and an assumed purity of 97%, but your real NaOH purity happens to be 100%, the actual superfat in the soap is going to be around 2%. I'd certainly shower with soap like that. And it will have more lather than soap with a higher superfat -- more lather is another benefit of using sufficient superfat, but not overdoing it.

Another perspective -- Most commercial soap made nowadays is made with zero superfat or a very slight superfat of less than 1%.