Soap/Lye Calculators; A guide

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seven

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yer welcome. yes, more water means more time to "play" with the batter. this can benefit you if using a temperamental fo for example, or doing intricate swirls/lotsa colors.

also, temp matters too. soaping at higher temp can give you quicker trace, thus i like to soap rt (room temp).
 

Willow42

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Help please

I am new to CP soapmaking and I am using a recipe from my suppliers website. I need to double the recipe but not sure how to work out how much lye I need. I have looked at some lye calculators and I'm getting very confused as to how to work it out. This is the recipe below, can someone please help me with this. Thanks

INGREDIENTS (excluding colour & fragrance)
12 oz (340g) of cold, clean water
125g of sodium hydroxide (caustic soda) beads or pearls
1lb (454g) olive oil (preferably pomace grade but virgin or extra virgin will do)
10oz (284g) coconut oil (hard variety)
6oz (170g) palm oil (hard variety)
1/4 tsp vitamin E oil
 

The Efficacious Gentleman

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I am new to CP soapmaking and I am using a recipe from my suppliers website. I need to double the recipe but not sure how to work out how much lye I need. I have looked at some lye calculators and I'm getting very confused as to how to work it out. This is the recipe below, can someone please help me with this. Thanks

INGREDIENTS (excluding colour & fragrance)
12 oz (340g) of cold, clean water
125g of sodium hydroxide (caustic soda) beads or pearls
1lb (454g) olive oil (preferably pomace grade but virgin or extra virgin will do)
10oz (284g) coconut oil (hard variety)
6oz (170g) palm oil (hard variety)
1/4 tsp vitamin E oil
From the point of view of lye to oils, this is fine.

Might be a bit too much coconut oil if you have sensitive or easily dry skin. If so, make a post with some details and lots of hints will come up
 

Willow42

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Thank you The Efficacious Gentleman, I wouldn't just double the lye though if I was doubling the recipe would I???
 

Saponista

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I concur with efficacious gentleman that there's a bit much coconut oil in that recipe though. I would find it a bit harsh on my sensitive skin.
 

Saponista

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I would add some castor oil to improve bubbles and creaminess and drop the %coconut down. Many other people will have hugely varying ideas of what makes a good bar of soap though. It's down to personal preference but I would have a play with some small batches using different ratios of oils until you get something you are happy with.
 

Willow42

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So if I put some castor oil in would I reduce the amount of coconut oil by the same amount of castor oil I would put in?
 

Saponista

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You need to use a lye calculator if you change the oils in the recipe. Each oil takes a different amount of lye to completely react with it. Have a go with soap calc. I know it looks daunting but it's really easy once you get the hang of it. In box 2 put the amount of oils you want in the recipe. If you want double the batch you made before just add up the oil weight, double it and put that number into the box. Leave box 3,4 and 5 as they are (you can learn how to use those afterwards) add the oils you are interested in in box six and play around with the percentage of those oils in your recipe. Click calculate which is number 7 and view or print recipe it will open you up a new box telling you all the things you need for your recipe. There will also be a box telling you different soap qualities and where your soap number falls within that range. Play around until you get the hardness creaminess etc, that you want. I would just print out a new recipe for you with castor but you will become so much more confident if you do it yourself.
 

scottief

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I have a quick question about the MMS Calculator. Im new to soap making and we made our 2nd batch last night. When using MMS the water about was 13-19 ounces. How do I know how much water to add when it tells me to use between the certain amounts.

I was at a soap store yesterday and she printed me off a recipe with MMS and she told me to use the number 5 lye on the chart. thanks
 

The Efficacious Gentleman

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I have a quick question about the MMS Calculator. Im new to soap making and we made our 2nd batch last night. When using MMS the water about was 13-19 ounces. How do I know how much water to add when it tells me to use between the certain amounts.

I was at a soap store yesterday and she printed me off a recipe with MMS and she told me to use the number 5 lye on the chart. thanks
The water amount can vary depending on what you want to do. It needs to be at least the same weight as the lye, but generally people use different amounts of water depending on the soap and the circumstances. To start off with, go more towards the higher amount than the lower - it makes it easier to dissolve the lye in the water, for one thing!

As for the "5 on the chart" - I think you mean a 5% superfat. That's pretty standard for many recipes, but there are often times that we would want to go above or below that
 

saffy

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I thought it would be helpful to everyone to put together a little guide to the soap calculators that were available online, as well as some relevant information.

I would like this to be an evolving thread because I realize that there are quite a few calculators available, and there are most likely some more to come with the new development of technology. My advice is to read as much as you can on each of these websites to gain an open perspective, and as much information as possible, as well as ask questions on the SMF.

For now, I have included the calculators I have found to be most popular within the forum. Feel free to post any questions you may have as well (we realize that these calculators can be quite confusing at first glance), so don't be shy!! The only stupid question is a question that is never asked!

Should you wish to add anything to this thread, please feel free to PM me and I would be happy to oblige!

Note: The calculations may vary from calculator to calculator.

First, I highly recommend that you read this introductory post by our lovely site admin (Thank you Mandy!):

Using a lye calculator

As well as read the info posted on this website about oil properties that may help with getting a general idea for the oils that you will use. Many of the calculator websites have similar listings:

http://www.soapnuts.com/indexoils.html


Soap/Lye Calculators:



1.) SoapCalc

http://www.soapcalc.com/default.asp

Description:
This site offers a wide range of possibilities, the user is able to enter ingredients as a weight or percent as well as adjust properties of the soap such as super fat/discount %. This site has loads of useful information, one link I found particularly useful when i was first starting out was the "what will I need" link, which gives the inexperienced soaper a concise list of supplies needed to start soaping with.


2.) 'Majestic Mountain Sage' lye calculator

http://thesage.com/calcs/lyecalc2.php

Description:
In this calculator, users are able to input the amount of oils in percent of total oils, there are also clickable links leading to oil properties as well as suggested amounts of use in recipe's. This site also includes a table after the recipe is calculated that lets the user choose a super-fat percent to be used in the recipe.


3.) SoapMaker

http://www.soapmaker.ca

Description:

Note: this is a free trial, users must purchase the full program after trial period expires.

"Create your own recipes, selecting from more than 50 types of base oils. Include your additives too. SoapMaker calculates lye and water, as well as the cost per bar using your ingredient costs. Experiment with recipes and see how they'll turn out before you make the soap... SoapMaker's unique recipe qualities graph shows you the predicted hardness, lather and moisturizing qualities. Compare different recipes and see the results of changes instantly using the dynamic graph feature .Store all your recipes and organize them by category, type, date and cost With SoapMaker Professional, manage your stock of ingredients and products made... your inventory adjusts automatically whenever you "make a batch" (quoted from soapmaker website"


4.) Maple Springs (added by Paul)

http://www.maplesprings.com/soapcalc.html

Description:

"To use the Maple Springs Farm soap lye calculator... simply enter in number of ounces per oil and the amount of lye, water, fragrance, and pigments will be automatically calculated for you...The Calculator is for Sodium Hydroxide = NAOH " This site is quite useful, it gives feedback regarding the size of the recipe as well as how many ounces of essential oils, and oxide/pigments are recommended for the given recipe size. This is quite a valuable tool to if you input recipes that have already been formulated to determine the right coloring amounts and essential oils, or formulate your own!
Last time I looked, which was a while ago admittedly, these lye calculator sites failed to provide any source references for their SAP values. When I contacted them replies were generally along the line of 'based on historic values' but still no actual references. One site did suggest a recently published book which apparently gives sources.

In the end I used the SAP values stated in the Codex Alimentarius (a formal document of international food standards started in 1964 by the FAO and WHO) and set up my own spreadsheet to calculate NaOH required for my recipes.
 

seven

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In the end I used the SAP values stated in the Codex Alimentarius (a formal document of international food standards started in 1964 by the FAO and WHO) and set up my own spreadsheet to calculate NaOH required for my recipes.
do you have a link to it? i am curious to see, and so far i can only find the sap for KOH, and not NaOH (in the Codex).
 

saffy

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SAPs and converting from KOH to NaOH

Seems most SAPs are worked out for KOH so you need to convert to NaOH.

Work out your KOH SAP based on your oil proportions.

Then determine NaOH needed by multiplying your KOH SAP by 39.997/56.106 (or 40/56) which comes from:


Sodium hydroxide, Molar mass = 39.997 g/mollPotassium hydroxide, Molar mass = 56.1056 g/mol

The Codex Al. gives a SAP range - I took the top of the range for each oil which is higher than values returned by the online calculators I have tried. Mine have all worked fine - I have tested batches with an industrial quality certified pH probe (the pH strips are not appropriate for soaps) and all pHs fine - they compare well to commercial bar soap which I also pH tested out of interest.

I also spent a headbreaking couple of hours working out theoretical stoichiometrical SAP values based on the Codex Al. fatty acid profiles for each oil - and was amazed that they compared well with the practical determinations which in most cases were done a long time ago. My previous life as an analytical chemist helps no end!

According to a very helful gentleman at the [FONT=verdana,geneva]The Federation of Oils, Seeds and Fats Associations (FOSFA) - SAP testing is a thing of the past and most quoted values will be somewhat dated - which raises the question of the relevance of these SAP values today given the modernisation of farming, processing and storage methods and subsequent potential for changes in the fatty acid profiles of the oils we use?
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