Lye Heavy Soap

[TheGecko]

I disagree with you on the rounding down being an issue.

I perhaps should have qualified my statement a little more by adding that it is going to depend on the number of ingredients and amounts thereof. I use 6 ingredients; if I round down what SoapCalc says for a 64oz batch, I lose 3 oz of oils/butters, but depending on my percentages, I could lose almost 6 oz. For my particular combination of oils at 33% Lye Concentration, my water is 18.52, my Lye is 9.12 (2% SuperFat).

For the last two years the importance of accurate measurements has been drilled into my head, along with using a single soap calculator. Now you are basically saying that because SAP numbers are a 'range' and no one has pure lye, close is good enough. I'm sorry, but I can't agree with that...not with something that is going to be used on my face, my lady bits and my grandchildren.

 

[DeeAnna]

"...For the last two years the importance of accurate measurements has been drilled into my head, along with using a single soap calculator. ..."

I agree -- accurate measurements and consistency are important skills of a good soap maker. Sloppy technique only gets a person in trouble. What I have been trying to explain is about what level of accuracy is needed.

Frankly, you aren't going to make better or safer soap by accurately weighing fats and lye to 0.01 gram tolerance than another soap maker who accurately weighs the same ingredients to 1 gram tolerance.

The reality is a 1 gram tolerance is sufficiently accurate for the purpose of most soap making. You can certainly measure to a stricter tolerance, but understand this is not likely to result in a measurably better or safer soap. Your lady bits and your grandchildren will be safe either way.

On the other hand, an analytical chemist may have to accurately weigh chemicals to 0.001 gram tolerance or better because this higher accuracy does make a measurable difference in this kind of work. Been there, done that. But there is no point to applying the rigor required for analytical chemistry to the process of making soap.

Rounding is another fact of life, whether you're an analytical chemist or a kitchen chemist. Pretty much all numbers are rounded values, so rounding is a fact of everyday life. Rounding in a consistent way isn't about sloppiness, it's another aspect of working in a methodical and accurate way.

Here's an example -- The value of pi is an infinitely long number. Most of the time when I do calculations, I round pi to 3.14, because that's good enough for everyday work. But sometimes I round pi to 3.1416 when greater accuracy is important.

Recognizing when I should use 3.1416 versus 3.14 isn't about sloppiness. It's about choosing a level of accuracy that's appropriate for the situation. Soap making is no different.

"...if I round down what SoapCalc says for a 64oz batch, I lose 3 oz of oils/butters ..."

I am quite certain you're using a scale that reads in ounces to several decimal places, so why have you gotten the idea you would round to whole ounces? Weights should always be rounded to the last significant digit for the scale you're using.

The KD7000 or KD8000 scale weighs to whole grams and to a hundredth of an ounce. If you are using one of these scales, you'd round up or down to the nearest whole gram or nearest hundredth of an ounce depending on what units you're using.

"...Now you are basically saying that because SAP numbers are a 'range' and no one has pure lye, close is good enough. ..."

Working accurately and methodically is always important. It's also important to match the degree of accuracy to the requirements of the task. I have found that having a better understanding about the numbers used in soapmaking has given me a better insight into what is really important and what is less so, and I wanted to share that with others. But if this last attempt of mine to explain is still falling short, I concede defeat -- we will have to agree to disagree.

 

[TheGecko]

But if this last attempt of mine to explain is still falling short, I concede defeat -- we will have to agree to disagree.

No need to concede as I wasn't responding to you, I was responding to @earlene.

 

[Peachy Clean Soap]

The KD 7000 is a fine scale for soapmaking. It measures to 1 gram accuracy and to 0.05 oz accuracy. For very small batches, a jewelers scale is a good choice. But for a soap batches of even only 350 grams of oil, I am quite confident with the measurements I get with my scale using a 3% SF. I've even had fine results with 0% SF batches using this scale and don't end up with lye heavy soap.

I do sometimes use my jeweler's scale for measuring fragrances, but for the most part, I only use that scale when I need to measure very small amounts of ingredients, not for measuring the basic oils.

I disagree with you on the rounding down being an issue. Remember in the first place that soap calculators are not as precise as one may expect. The SAP numbers come from a range, so they start out inexact from the beginning. That's for the SAP values. ALSO lye purity is usually set by default at 100% in many lye calculators, but no one has 100% pure lye once it's been open to the air; moisture is drawn to the lye, which decreases it's purity.

If you don't change your lye purity setting in your lye calculator (I am pretty sure most soapmakers do NOT), then it's already built into the calculator that your SF will be even higher than whatever you set it at, be it the default 5% or even 0%, which I have done a few times with no problems whatsoever. One can test the lye purity and DeeAnna is the only soapmaker I am aware of who does this on a regular basis for all of her soaps. But she also has more accurate information for her oils SAP numbers if I remember correctly, so her calculations are far more accurate for her soap than for the average soapmaker.

Only once have I made a lye heavy soap and that was on purpose following an experiment here on SMF for Andalusian Castile soap.

The other thing I would recommend is to only use grams and not ounces for weighing soap ingredients. Grams provides a more accurate weight than ounces.

Thank you for your in depth info' I think my scale is similar to yours' I just checked its the KD-7000 as well, I mentioned in thread above I'm going to weigh in grams moving forward too. Oh about the "Lye" very true no lye is 100% pure & not all lye is equal' even when purchased at the same company. I don't want to discredit any soap company's so wont say their name however Id ordered lye from a well know soap supply Co & not happy w/ their lye' it didn't dissolve to a clear liquid as Im used to' and upon cooling down had all kinds of particles in it @ over 100* f so wont be ordering lye from them again. As of late I ordered from a Comp I haven't tried before & such a big difference in their lye from the previous Comp, their lye dissolved clear w/ very little particles.
Not all Lye is not created equal! thats no Lie!. My Soap Being Lye Heavy ( My Bad ).

"...For the last two years the importance of accurate measurements has been drilled into my head, along with using a single soap calculator. ..."

I agree -- accurate measurements and consistency are important skills of a good soap maker. Sloppy technique only gets a person in trouble. What I have been trying to explain is about what level of accuracy is needed.

Frankly, you aren't going to make better or safer soap by accurately weighing fats and lye to 0.01 gram tolerance than another soap maker who accurately weighs the same ingredients to 1 gram tolerance.

The reality is a 1 gram tolerance is sufficiently accurate for the purpose of most soap making. You can certainly measure to a stricter tolerance, but understand this is not likely to result in a measurably better or safer soap. Your lady bits and your grandchildren will be safe either way.

On the other hand, an analytical chemist may have to accurately weigh chemicals to 0.001 gram tolerance or better because this higher accuracy does make a measurable difference in this kind of work. Been there, done that. But there is no point to applying the rigor required for analytical chemistry to the process of making soap.

Rounding is another fact of life, whether you're an analytical chemist or a kitchen chemist. Pretty much all numbers are rounded values, so rounding is a fact of everyday life. Rounding in a consistent way isn't about sloppiness, it's another aspect of working in a methodical and accurate way.

Here's an example -- The value of pi is an infinitely long number. Most of the time when I do calculations, I round pi to 3.14, because that's good enough for everyday work. But sometimes I round pi to 3.1416 when greater accuracy is important.

Recognizing when I should use 3.1416 versus 3.14 isn't about sloppiness. It's about choosing a level of accuracy that's appropriate for the situation. Soap making is no different.

"...if I round down what SoapCalc says for a 64oz batch, I lose 3 oz of oils/butters ..."

I am quite certain you're using a scale that reads in ounces to several decimal places, so why have you gotten the idea you would round to whole ounces? Weights should always be rounded to the last significant digit for the scale you're using.

The KD7000 or KD8000 scale weighs to whole grams and to a hundredth of an ounce. If you are using one of these scales, you'd round up or down to the nearest whole gram or nearest hundredth of an ounce depending on what units you're using.

"...Now you are basically saying that because SAP numbers are a 'range' and no one has pure lye, close is good enough. ..."

Working accurately and methodically is always important. It's also important to match the degree of accuracy to the requirements of the task. I have found that having a better understanding about the numbers used in soapmaking has given me a better insight into what is really important and what is less so, and I wanted to share that with others. But if this last attempt of mine to explain is still falling short, I concede defeat -- we will have to agree to disagree.

Couldn't agree more' & appreciate your knowledge & willing to share freely! Understanding The Basics Of Soaping
( which isn't so basic ) is quite a challenge but must be understood fully for a strong foundation to continue to build & improve on when creating a well balanced perfect Bar Soap' if theirs such a thing.

Couldn't agree more' & appreciate your knowledge & willing to share freely! Understanding The Basics Of Soaping
( which isn't so basic ) is quite a challenge but must be understood fully for a strong foundation to continue to build & improve on when creating a well balanced perfect Bar Soap' if theirs such a thing.

Help Please. Ok my water amount is 242.98 g my scale has no decimal in grams. do I use kg weight sence it has a decimal ? I hope im not sounding like a complete *****, or keep on gram weight and round up? water amnt required 242.98 of water: converted up to 243.

Help Please. Ok my water amount is 242.98 g my scale has no decimal in grams. do I use kg weight sence it has a decimal ? I hope im not sounding like a complete *****, or keep on gram weight and round up? water amnt required 242.98 of water: converted up to 243.

Or probably round down sense I don't want to increase my water which Im guessing?:
242.98g of water rounded down would be 242g of water.
Thank you in advance

Or probably round down sense I don't want to increase my water which Im guessing?:
242.98g of water rounded down would be 242g of water.
Thank you in advance

I just reread post above and I round up or down to the nearest hundredth, I think I got it, sorry if im a pain in the ***. .

 

[DeeAnna]

If you have a scale that only weighs to whole grams and if you're using the "round up for fat and round down for lye" method, 242.89 grams would round DOWN to 242 grams for lye.

You would round UP to 243 grams for everything else -- fats, water, etc.

Don't use the kilograms (kg) setting. It's not like you can't use it ... just that it's not going to be any better or more helpful.

Just stick to units of grams and you'll be fine.

(PS -- This isn't the proper method of rounding for normal math and statistical stuff. If anyone wants to know the correct way to round to make a math or stats teacher happy, I will be glad to explain.)

 

[Primrose]

The purpose of 'super fat' is to make your soap more 'moisturizing' with unsaponified oils. It's NOT supposed to be used a safety net. I know several people here who do NOT use a 'super fat'...they have properly calibrated scales and are precise in their measurements.

I actually disagree with this. Except for the odd recipe such as a 100% coconut oil soap ... A 'normal' recipe isnt moisturizing (no soap is) and if formulated correctly a soap with zero superfat can be entirely gentle and non stripping on the skin. In my mind the superfat level is absolutely a safety net especially for new soapers. Also in my mind it makes more sense to have a gentle recipe that doesn't overly strip the skins natural oils, compared to a soap that strips the skins natural oils and then attempts to return moisture to the skin with the addition of other butters/fats

 

[Bladesmith]

You don’t have to have a scale with 0.1 gram precision but I prefer it. For one, it helps to satisfy my OCD. With that out of the way, it also gives you more information. I pour all my oils directly into a single pot that sits on my scale. It’s easier to make a mistake like that and knowing whether I need to add 1.4g or 0.1g to get to the weight I want to get to is nice to know. I usually overshoot or undershoot by a small amount and don’t really sweat it. And while it doesn’t matter too much if I’m a gram over here or a gram under there.... in the interest of consistency, I like to get it as close as I reasonably can. If you can have extra precision, not sure why you wouldn’t go for it unless it’s a cost thing or it won’t handle the weight of oils you use.

I’ve also used the same scale for measuring out EO blends and very small batches of other soap like shave soap. It is especially helpful for those situations.

 

[Peachy Clean Soap]

If you have a scale that only weighs to whole grams and if you're using the "round up for fat and round down for lye" method, 242.89 grams would round DOWN to 242 grams for lye.

You would round UP to 243 grams for everything else -- fats, water, etc.

Don't use the kilograms (kg) setting. It's not like you can't use it ... just that it's not going to be any better or more helpful.

Just stick to units of grams and you'll be fine.

(PS -- This isn't the proper method of rounding for normal math and statistical stuff. If anyone wants to know the correct way to round to make a math or stats teacher happy, I will be glad to explain.)

Ok very good' thats what I did' I appreciate your help. Im happy to report soap batter didn't accelerate & I added honey' reduced water amount for beer' only .40g and added color along w/ FO, had enough time to try a feather swirl' I dont know if it's my imagination or wishful thinking, but soap felt more manageable & was behaving nicely. I've covered & put it in the cabinet. Well see how it turns out in the morning & in 6 weeks Fingers crossed. I'll post a picture after I cut it. Thx again for your help.

You don’t have to have a scale with 0.1 gram precision but I prefer it. For one, it helps to satisfy my OCD. With that out of the way, it also gives you more information. I pour all my oils directly into a single pot that sits on my scale. It’s easier to make a mistake like that and knowing whether I need to add 1.4g or 0.1g to get to the weight I want to get to is nice to know. I usually overshoot or undershoot by a small amount and don’t really sweat it. And while it doesn’t matter too much if I’m a gram over here or a gram under there.... in the interest of consistency, I like to get it as close as I reasonably can. If you can have extra precision, not sure why you wouldn’t go for it unless it’s a cost thing or it won’t handle the weight of oils you use.

I’ve also used the same scale for measuring out EO blends and very small batches of other soap like shave soap. It is especially helpful for those situations.

I may have a just a little of OCD' lol I want my measurements to be perfect' however its nice to have some adjustment to the positive or negitive in our lye' fats & oils, Now that I understand it will become easier weighing in grams. Ive been a HP soaper, I've just switched to CP, I think its so much harder to CP' in that its less forgiving the soaps gotta be balanced perfect. HP I bring it through the different stages I want it to volcano in the pot a few times' at end add my extra SF & whatever else Ive planned on adding & pour in mold quickly & I'm good to go lol. CP oh goodness I'm worried if its going to volcano' or ifs its gone through Jell completely' If its overheating & going to crack' so many variables. But Im able to use color w/ pretty designs unlike HP its hard to pull off.

 

[earlene]

No need to concede as I wasn't responding to you, I was responding to @earlene.

And I based my above statement on many of the things that I have learned from DeeAnna and others here on how lye calculators are designed as well as soap making in general, in addition to supporting information from various other soapmaking experts along the way. I appreciate DeeAnna's response because it clarifies almost everything I would have tried to say had she not said it so well herself.

I would like to point out though, that I did NOT say anything about rounding to the nearest ounce when a scale measures to the hundredth of an ounce, and certainly did not suggest injudicious rounding up or down. I don't really think you would do that, either, because I don't think you are that sloppy. In review of the statement of yours to which I was responding, and tommysgirl's post to which you were responding before that, I can only conclude you read that I was advocating rounding down on all oils, but since that is not even what tommysgirl said she does anyway, I am not sure why that is what you thought I meant. She said she uses grams and rounds up on oils and down on lye. In any case, I did not intend to address her specific method of rounding down and up, but the concept in general.

Therefore, I wish to clarify with an example of my own to show you what it means to me and how it can be done responsibly. My example is for an average (for me) batch size, but works just as well with a larger batch size.


When making soap using a formula that has partial grams to calculate, I do not lose more than a gram or two of total weight by judiciously rounding down & rounding up. (As I mentioned before, I recommend weighing in grams for better accuracy, but if you choose to weigh in ounces to the 1/100th of an ounce, it works that way just as well, but I use grams.)

Please look at this example of why I support judicious rounding up and down and why I say it works well with soap. When I round down or up for partial gram measures in my soap formula to the next full gram, it makes no noticeable difference in the larger scheme of things for a 500 gram total batch size soap. See how it is done:

Here is a hypothetical soap formula for a 500 gram batch of a 3 oil soap, where the oils total 343 grams:
55% is palm oil (188.65 grams)
30% is almond oil (102.9 grams)
15% is coconut oil (51.45 grams)
with 3% SF and [33.33% Lye] (using my masterbatch lye solution of 50:50 ratio of NaOH to H2O)
(Total Batch Size = 500.21 grams)

I will round up on both Palm Oil & Almond Oil to the nearest gram and round down on the Coconut Oil, in order to bring my total oil weight to exactly the same as it would be had I not had to round up or down (343 grams of oils). I round up on my mb lye solution from 97.94 grams to 98 grams, and round up from 48.98 grams to 49 grams for the additional liquid. I will round down my 3% FO from 10.29 grams, to 10 grams.

So what have I gained or lost in this rounding? I lost 0.21 grams total from the total batch size, which really is Virtually Nothing. Did I change the SF in any noticeable amount? No, by adding a mere 0.06 grams of lye solution, which is really only 0.03 grams of NaOH, even in a 500 gram batch of soap the SF does not change enough to notice. Not even when I change the numbers in the calculator to look for the change. It takes a lot of manipulation in the calculator, but there isn't even a 1/10 change in the SuperFat, and some calculators don't even register that kind of change. And is the 0.29 grams of FO going to be missed? Not likely.

So I ask you, given these minuscule changes, how is this judicious rounding up and down problematic? It is not. The soap will be just the same as it was had I used my jewelers scale to measure to a hundredth of a gram. Why would I bother, when it is not at all necessary? I can still use the soap on my lady bits; my granddaughter still likes it and uses it; and if I used soap on my face, I'd be fine with using it there, too.

You are right, and I shouldn't think of it that way - and in truth I don't, in all honestly, see it as a safety net for which I can account for error. I guess, being new to soaping I am still learning the correct way of expressing things. So I truly appreciate your pointing that out because I don't want anyone to get a wrong idea from something I posted. I had stopped using 5% SF because I had read that many folks are happy with 3% and wanted to give it a try. Also my husband said that he thought the tub felt slippery after using a soap I made and I wanted to see if the SF possibly had anything to do with that. I use a KD-7000 scale that I am pretty happy with, but the one thing that kind of bothers me is this - my recipes give me measurements in tenths and hundredths of grams and my scale weighs in whole grams. So I usually round up for oils down for lye. I always feel like I'm making a mistake, even though I'm not. I'm not an avid note taker, which is something I need to work on. I feel like I could have found my error with this batch if I took notes on my measurements along the way.

Tommysgirl, the KD-7000 is fine. If you look at my example above, please notice that by rounding up and rounding down in the way I describe you would not have any significant changes to your overall formula. Rounding to the nearest gram is a reasonable practice while making soap. Remember that one gram is 1/28th of an ounce. That is a very small amount, and rounding up or down from a partial gram to the nearest gram is not a significant amount.

As far as your error that lead to the lye-heavy soap and you say maybe you left out an oil and your lack of good notes, I suggest checking off each ingredient as you finish weighing it, then add it to the pot. Once you get into that habit, you'll know if you left out something. And with that habit, you can add another tiny note should you need one, like (" 100 g " for rounded up to from 99.8 g or something similar). That is if you write out or print out your formula for each batch, like I do & so do many others.

 

[cmzaha]

A suggestion I always make is to tare you soaping containers and mark down the empty weight. If you think you left out an oil you can usually figure it out by weighing your container. This little trick has saved me many times when I have become distracted and noticed my bucket did not seem like it was filled quite right. Rechecking the weight would tell me if everything was in the soaping bucket or not.

 

[tommysgirl]

Tommysgirl, the KD-7000 is fine. - Rounding to the nearest gram is a reasonable practice while making soap.

I suggest checking off each ingredient as you finish weighing it, then add it to the pot. Once you get into that habit, you'll know if you left out something. And with that habit, you can add another tiny note should you need one, like (" 100 g " for rounded up to from 99.8 g or something similar).

Thank you Earlene. I truly appreciate all the advice given here in this group. I still have a great deal to learn and I take it all into consideration. I developed the practice of rounding because I found it to be widely used in my research. Like I mentioned, I had been rounding up in oils and down in lye and by doing so assumed (I know - I can hear my 7th grade science teacher saying "***-u-me" here) that any real change to the end product would be a slight increase in sf - since I was not increasing the lye amount at all - and therefore would be safe if passed the zap test. I feel that, for me personally, rounding to the nearest gram as per your example will give the most accuracy. Thank you for your detailed explanation, as I will be doing this going forward. As for the batch in question, I had begun checking off the ingredients as I added them, but dropped off somewhere in the middle. I was actually pretty confident with this batch that I had performed everything correctly, until it was time to cut it of course. As for the oil I feel I may have left out -I felt certain that I remembered measuring them all out, but since I had not checked them all off I can't be sure. So in truth it could have been a missed oil, or a miss-measurement. It was a larger batch than I usually make and I remember wondering if it was all going to fit into my soaping bowl. I think it was at that point that my thoughts got hijacked and I stopped checking things off. In either case better notes would have told the whole story and I just didn't have that on this batch Lesson learned!! I have begun not only checking off everything as I add to my bowl, but also writing down next to the printed measurement (similar to what you mention above), the rounded measurement that I actually see on my scale. So not only do I know I added it, but I know exactly how much and that I did indeed round properly to the correct measurement of the particular oil being added and not to some random number that just happened to pop into my head at the moment. No more guess work there.

A suggestion I always make is to tare you soaping containers and mark down the empty weight. If you think you left out an oil you can usually figure it out by weighing your container.

This is an excellent Idea, and I thank you very much for it! I have weighed my containers, but have not made a practice of double checking myself. With this batch I didn't think it was necessary because I 'thought' I had everything This experience has taught me that this is also something I should be doing going forward for every batch. At the very least until I have more experience under my belt.

 

[TheGecko]

@earlene

Apologies for misunderstanding and I greatly appreciate you take the time to clarify.

And to @DeeAnna. I realized how abrupt my response was to you above and I apologize for that.

 

[melinda48]

Thank you Earlene. I truly appreciate all the advice given here in this group. I still have a great deal to learn and I take it all into consideration. I developed the practice of rounding because I found it to be widely used in my research. Like I mentioned, I had been rounding up in oils and down in lye and by doing so assumed (I know - I can hear my 7th grade science teacher saying "***-u-me" here) that any real change to the end product would be a slight increase in sf - since I was not increasing the lye amount at all - and therefore would be safe if passed the zap test. I feel that, for me personally, rounding to the nearest gram as per your example will give the most accuracy. Thank you for your detailed explanation, as I will be doing this going forward. As for the batch in question, I had begun checking off the ingredients as I added them, but dropped off somewhere in the middle. I was actually pretty confident with this batch that I had performed everything correctly, until it was time to cut it of course. As for the oil I feel I may have left out -I felt certain that I remembered measuring them all out, but since I had not checked them all off I can't be sure. So in truth it could have been a missed oil, or a miss-measurement. It was a larger batch than I usually make and I remember wondering if it was all going to fit into my soaping bowl. I think it was at that point that my thoughts got hijacked and I stopped checking things off. In either case better notes would have told the whole story and I just didn't have that on this batch Lesson learned!! I have begun not only checking off everything as I add to my bowl, but also writing down next to the printed measurement (similar to what you mention above), the rounded measurement that I actually see on my scale. So not only do I know I added it, but I know exactly how much and that I did indeed round properly to the correct measurement of the particular oil being added and not to some random number that just happened to pop into my head at the moment. No more guess work there.


This is an excellent Idea, and I thank you very much for it! I have weighed my containers, but have not made a practice of double checking myself. With this batch I didn't think it was necessary because I 'thought' I had everything This experience has taught me that this is also something I should be doing going forward for every batch. At the very least until I have more experience under my belt.

I keep my soap recipes in plastic sheet protectors and use a grease pencil to mark off ingredients as I add them. Works every time! When I am done, I merely wipe the sheet off with a paper towel (or whatever works) and am ready to go. I began using this method when doing embroidery designs that involve a lot of colors. Has saved me many a time!

 

[tommysgirl]

I keep my soap recipes in plastic sheet protectors and use a grease pencil to mark off ingredients as I add them.

I love this idea! Thank you

 

[melinda48]

I love this idea! Thank you

You are most welcome! I thank my embroidery group leader formthis terrific suggestion! Keeps the paper clean too

 

[DeeAnna]

I should probably use your idea, @melinda48 -- my worksheets are usually super messy with dribbles of fat and smears from my gloves when I'm done.

 

[Peachy Clean Soap]

And I based my above statement on many of the things that I have learned from DeeAnna and others here on how lye calculators are designed as well as soap making in general, in addition to supporting information from various other soapmaking experts along the way. I appreciate DeeAnna's response because it clarifies almost everything I would have tried to say had she not said it so well herself.

I would like to point out though, that I did NOT say anything about rounding to the nearest ounce when a scale measures to the hundredth of an ounce, and certainly did not suggest injudicious rounding up or down. I don't really think you would do that, either, because I don't think you are that sloppy. In review of the statement of yours to which I was responding, and tommysgirl's post to which you were responding before that, I can only conclude you read that I was advocating rounding down on all oils, but since that is not even what tommysgirl said she does anyway, I am not sure why that is what you thought I meant. She said she uses grams and rounds up on oils and down on lye. In any case, I did not intend to address her specific method of rounding down and up, but the concept in general.

Therefore, I wish to clarify with an example of my own to show you what it means to me and how it can be done responsibly. My example is for an average (for me) batch size, but works just as well with a larger batch size.


When making soap using a formula that has partial grams to calculate, I do not lose more than a gram or two of total weight by judiciously rounding down & rounding up. (As I mentioned before, I recommend weighing in grams for better accuracy, but if you choose to weigh in ounces to the 1/100th of an ounce, it works that way just as well, but I use grams.)

Please look at this example of why I support judicious rounding up and down and why I say it works well with soap. When I round down or up for partial gram measures in my soap formula to the next full gram, it makes no noticeable difference in the larger scheme of things for a 500 gram total batch size soap. See how it is done:

Here is a hypothetical soap formula for a 500 gram batch of a 3 oil soap, where the oils total 343 grams:
55% is palm oil (188.65 grams)
30% is almond oil (102.9 grams)
15% is coconut oil (51.45 grams)
with 3% SF and [33.33% Lye] (using my masterbatch lye solution of 50:50 ratio of NaOH to H2O)
(Total Batch Size = 500.21 grams)

I will round up on both Palm Oil & Almond Oil to the nearest gram and round down on the Coconut Oil, in order to bring my total oil weight to exactly the same as it would be had I not had to round up or down (343 grams of oils). I round up on my mb lye solution from 97.94 grams to 98 grams, and round up from 48.98 grams to 49 grams for the additional liquid. I will round down my 3% FO from 10.29 grams, to 10 grams.

So what have I gained or lost in this rounding? I lost 0.21 grams total from the total batch size, which really is Virtually Nothing. Did I change the SF in any noticeable amount? No, by adding a mere 0.06 grams of lye solution, which is really only 0.03 grams of NaOH, even in a 500 gram batch of soap the SF does not change enough to notice. Not even when I change the numbers in the calculator to look for the change. It takes a lot of manipulation in the calculator, but there isn't even a 1/10 change in the SuperFat, and some calculators don't even register that kind of change. And is the 0.29 grams of FO going to be missed? Not likely.

So I ask you, given these minuscule changes, how is this judicious rounding up and down problematic? It is not. The soap will be just the same as it was had I used my jewelers scale to measure to a hundredth of a gram. Why would I bother, when it is not at all necessary? I can still use the soap on my lady bits; my granddaughter still likes it and uses it; and if I used soap on my face, I'd be fine with using it there, too.




Tommysgirl, the KD-7000 is fine. If you look at my example above, please notice that by rounding up and rounding down in the way I describe you would not have any significant changes to your overall formula. Rounding to the nearest gram is a reasonable practice while making soap. Remember that one gram is 1/28th of an ounce. That is a very small amount, and rounding up or down from a partial gram to the nearest gram is not a significant amount.

As far as your error that lead to the lye-heavy soap and you say maybe you left out an oil and your lack of good notes, I suggest checking off each ingredient as you finish weighing it, then add it to the pot. Once you get into that habit, you'll know if you left out something. And with that habit, you can add another tiny note should you need one, like (" 100 g " for rounded up to from 99.8 g or something similar). That is if you write out or print out your formula for each batch, like I do & so do many others.

Thx for taking the time & explaining' so very helpful. . Also I want to thank "Everyone Else" that committed w/ your expert advise its such a big help' not only for myself but for many others. @DeeAnna , @ Tommysgirl , @cmzaha , @TheGecko, @BladeSmith, @Primrose, @Melinda ...