Sodium citrate

[Sonya-m]

I ordered some to use to counter the effects of the slightly hard water in my area

It's arrived today, the bag says trisodium citrate with a CAS of 6132-04-3 which when googled is trisodium citrate dihydrate

Is this the right thing?

 

[The Efficacious Gentleman]

If it turns out to be the wrong stuff, can you get citric acid? You can buy it over here for cooking and then you increase the lye a touch as the lye turns it in to sodium citrate.

 

[Sonya-m]

I haven't looked yet but am assuming I can. I went for the citrate to avoid having to increase the lye (I know it wouldn't have been hard, I just want to make it as easy as poss)

 

[Susie]

Look in the canning supplies for citric acid. That's where I find it here.

 

[Saponista]

I've searched but I can't find the saponification value for citric acid anywhere. Someone wrote on another forum it was 0.571 oz lye per oz citric acid monohydrate, but I am used to using grams so am a bit confused. I think it would be the same, 0.571g lye per g CA but I'm unsure as I see imperial measurements and begin to panic!

 

[Sonya-m]

Thanks everyone. DeeAnna confirmed on another thread for every 10g of citric acid I would need 6g extra lye but also confirmed I can used sodium citrate instead as this is just the byproduct of lye+citric acid so no need to alter my lye number

Just wanting to confirm this sodium citrate dihydrate is the correct thing

 

[The Efficacious Gentleman]

Thanks everyone. DeeAnna confirmed on another thread for every 10g of citric acid I would need 6g extra lye but also confirmed I can used sodium citrate instead as this is just the byproduct of lye+citric acid so no need to alter my lye number

Just wanting to confirm this sodium citrate dihydrate is the correct thing

Aye, which is why my post said that IF it isn't the right stuff and you want sodium citrate, you can use the acid and more lye.................

 

[Sonya-m]

Aye, which is why my post said that IF it isn't the right stuff and you want sodium citrate, you can use the acid and more lye.................

Sorry, I didn't mean to imply you didn't know sodium citrate could be used instead

 

[The Efficacious Gentleman]

No worries

I did some digging - trisodium citrate dihydrate is a chelator, and I also found this -

http://www.jungbunzlauer.com/en/products/citrics/trisodium-citrate-dihydrate.html

 

[Sonya-m]

Thanks - I guess I will give it a go in that case.

 

[SoapBro]

as stated before, trisodium citrate is the right stuff, i use it in every soap.

 

[RhondaJ]

as stated before, trisodium citrate is the right stuff, i use it in every soap.

at what ratio is this used in soap to fight the soap scum in hard water?

 

[nframe]

as stated before, trisodium citrate is the right stuff, i use it in every soap.

Why do you use it in every soap? What benefits does it bring? And, lastly, how much do you use? This is very intriguing...

 

[The Efficacious Gentleman]

I use citric acid and more lye (so I technically use sodium citrate) rather than the trisodium citrate, but it helps to improve lather in hard water and reduce soap scum

 

[nframe]

I use citric acid and more lye (so I technically use sodium citrate) rather than the trisodium citrate, but it helps to improve lather in hard water and reduce soap scum

How much citric acid do you use? 10g ppo and an extra 6g of lye?

 

[The Efficacious Gentleman]

Need to check my notes but I think it's 10g per 1000g oil - so 1% of oil weight. Plus 6g of lye per 10g of citric acid. That took some measuring when I was making 50g batches of shaving soap trials............................

 

[DeeAnna]

"...saponification value for citric acid..."

It doesn't have a saponification value, so you will never find that information. The only chemicals that have sap values are the ones that make soap. Citric acid doesn't make soap.

Trisodium citrate dihydrate is what you want. This is the full technical name. The "common name" for this chemical is just sodium citrate.

If you are using sodium citrate, then NO extra lye is needed.

If you are using citric acid, then you need 6 g extra NaOH for every 10 g of citric acid. Or 6 oz extra NaOH for every 10 ounces of citric acid. However you say it, it means exactly the same proportion of lye to acid.

Yes, the precise number is different than this, but you'd need a lab quality scale to measure out the extra decimal places, so forgeddabout it. Rounding to 6 g is good enough for our kitchen chemistry.

 

[Sonya-m]

Excellent! Thank you everyone! Glad it's the right thing, wasn't expensive either, 1kg for £1.89 plus £2.89 postage. I don't know if this is a good price or not

Another question now - do I add this to my water before I add my lye and let is dissolve before adding the lye?

Does it have any impact on trace times?

 

[Saponista]

Thanks DeeAnna

Do you find it really makes a difference EG? I have very soft water so don't have trouble with lather and scum but my parents have hard water and I want to make something that will work better for them too.

 

[nframe]

Excellent! Thank you everyone! Glad it's the right thing, wasn't expensive either, 1kg for £1.89 plus £2.89 postage. I don't know if this is a good price or not

Where did you buy this?