Peachy Clean Soap
Well-Known Member
Awesome appreciate your info & pict. It all starts w/ precise weights. Im thinking of weighing in grams as well' thinking its more accurate then weighing lbs ?. Soap batches are small' 3 Lbs has been my max.
Lye Heavy Soap
- Thread starter Peachy Clean Soap
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I agree with the advice that it's important to work methodically, have decent equipment, measure carefully, and keep good notes. But I can't entirely agree with some of the other advice being given in this thread --
A soap maker can reduce error by good technique and good equipment, but this does not eliminate error. A small superfat is indeed used as a safety net for the cold and hot process methods. It ensures there is a slight excess of fat in the finished soap, not an excess of alkali (NaOH or KOH), because there are two big sources of error that technique and equipment don't prevent --
Most handcrafted soap makers (including me) do NOT measure the saponification values for the actual fats going into our soap. Instead we assume the averaged sap values in our soap recipe calcs are good enough.
These assumptions about alkali purity and sap values introduce far more error than using a scale that reads to whole grams or using the "round up for fats, round down for alkali" rule of thumb.
***
A scale reading to 0.1 gram or 0.01 gram is not required for soap making unless you're making very small batches. If a person has a scale that reads to the nearest whole gram AND is making decent sized batches using at least 16 oz or 500 grams of fats, a scale reading to whole grams is sufficiently accurate. If a person wants to use a scale with more precision, that's perfectly okay, but it's not a requirement.
The rule of thumb to round UP the weights of fats and round DOWN the weight of lye to the nearest whole gram is another safety measure that many people use. Honestly, there's very little if any harm in it. If you do the math on the error introduced by this method of rounding, you'll see for yourself that the error introduced by this rule of thumb is very reasonable when making a decent-sized batch of soap.
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Like Carolyn, I routinely make soap with a lower superfat (typically 2-3%). I also correct for the purity of my alkali in my recipes. This correction further reduces the margin of safety -- in other words my 3% superfat is a "realer" 3% superfat than most people's. Even so, my soap isn't ever randomly and mysteriously lye heavy. If it's lye heavy, I've made a mistake.
If you are using an online calc and you've gotten a lye-heavy soap, it's not from using a 3% superfat or using a scale that reads to whole grams or using the "round up for fats, round down for lye" method.
It's far more likely that you've made a measurement mistake or omitted a fat, or something fairly significant like that. In that case, even a 10% superfat setting might not prevent the soap from being lye heavy.
***
Regarding weighing soap ingredients in pounds rather than grams or ounces -- If your scale can only display units of decimal pounds, it's probably not sufficiently accurate enough unless you're making quite large batches -- well over 10 pounds, let's say.
If your scale displays weights in mixed units of pounds and ounces, I would truly hate to use the scale. It's far too easy to make arithmetic errors when using mixed units.
If your scale reads in grams and ounces, pick whichever unit of weight that makes the most sense to you. Due to my chemistry training and work background, I use only grams for soap making.
I also think the weights in a soap recipe can be easier for humans to mentally process better if the weights are mostly whole numbers (6 grams) rather than decimal numbers (0.21 ounces). This is also another reason why it makes more sense to use grams.
A soap maker can reduce error by good technique and good equipment, but this does not eliminate error. A small superfat is indeed used as a safety net for the cold and hot process methods. It ensures there is a slight excess of fat in the finished soap, not an excess of alkali (NaOH or KOH), because there are two big sources of error that technique and equipment don't prevent --
Most handcrafted soap makers (including me) do NOT measure the saponification values for the actual fats going into our soap. Instead we assume the averaged sap values in our soap recipe calcs are good enough.
Most of us also accept our recipe calcs' assumptions about alkali purity. Most calcs assume NaOH is 100% pure, which is inaccurate. If a person types in 3% for the superfat setting and their calc assumes 100% NaOH purity, the real superfat in the soap is probably closer to 5-10%. This is quite a bit of error.These assumptions about alkali purity and sap values introduce far more error than using a scale that reads to whole grams or using the "round up for fats, round down for alkali" rule of thumb.
***
A scale reading to 0.1 gram or 0.01 gram is not required for soap making unless you're making very small batches. If a person has a scale that reads to the nearest whole gram AND is making decent sized batches using at least 16 oz or 500 grams of fats, a scale reading to whole grams is sufficiently accurate. If a person wants to use a scale with more precision, that's perfectly okay, but it's not a requirement.
The rule of thumb to round UP the weights of fats and round DOWN the weight of lye to the nearest whole gram is another safety measure that many people use. Honestly, there's very little if any harm in it. If you do the math on the error introduced by this method of rounding, you'll see for yourself that the error introduced by this rule of thumb is very reasonable when making a decent-sized batch of soap.
***
Like Carolyn, I routinely make soap with a lower superfat (typically 2-3%). I also correct for the purity of my alkali in my recipes. This correction further reduces the margin of safety -- in other words my 3% superfat is a "realer" 3% superfat than most people's. Even so, my soap isn't ever randomly and mysteriously lye heavy. If it's lye heavy, I've made a mistake.
If you are using an online calc and you've gotten a lye-heavy soap, it's not from using a 3% superfat or using a scale that reads to whole grams or using the "round up for fats, round down for lye" method.
It's far more likely that you've made a measurement mistake or omitted a fat, or something fairly significant like that. In that case, even a 10% superfat setting might not prevent the soap from being lye heavy.
***
Regarding weighing soap ingredients in pounds rather than grams or ounces -- If your scale can only display units of decimal pounds, it's probably not sufficiently accurate enough unless you're making quite large batches -- well over 10 pounds, let's say.
If your scale displays weights in mixed units of pounds and ounces, I would truly hate to use the scale. It's far too easy to make arithmetic errors when using mixed units.
If your scale reads in grams and ounces, pick whichever unit of weight that makes the most sense to you. Due to my chemistry training and work background, I use only grams for soap making.
I also think the weights in a soap recipe can be easier for humans to mentally process better if the weights are mostly whole numbers (6 grams) rather than decimal numbers (0.21 ounces). This is also another reason why it makes more sense to use grams.
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You mentioned several things I’ve been thinking a lot about . My scale, super fat ratio, and grams.. but with another ingredient.
I’ve started cutting the super fat ratio down to 3-4% because of our plumbing and that I read with goats milk, the extra fat makes up for it as well. I haven’t figured out how to calculate that, but it’s seems fine working with the lower super fat and I think I might be able to try 2%? I’ve made @Zany_in_CO no slime Castile with goat milk and it’s lovely. It made me wonder about using less super fat with other soaps. I use less than 20 coconut oil. Any suggestions whether I’m thinking ok or not would be appreciated. I also started measuring in grams rather than ounces and my scale measures to the gram but not less than. So when I try a smaller batch and have essential oil blends that are less than a gram I’m stumped as to what to do. I use the ecal to figure the amounts. Sorry for the lengthy rattling. Any advice you can give me is very appreciated
Yup, exactly my recipe.I make laundry soap with 100% coconut oil 0% sf... but I do 1 cup finely grated soap, 2 cups borax, 2 cups washing soda.
I just recently started adding oxi clean and the fragrance boosters not sure of the ratio cause I add full boxes and make a sh*t ton!
I also like to make big batches, bc it is a messy process, so I'd rather do a whole bunch at once and then not think about it for another year. This laundry soap works great for us, but I understand that not everyone wants to wash in hot water, or they may have hard water, which definitely makes the homemade stuff less effective.@Basil My scale doesn't do partial ounces, nor would I want to mess with that if it did. One gram is less than half an ounce, so measurements are far more precise using whole grams rather than whole ounces. And as @DeeAnna noted, errors are more likely when working with mixed units and decimal points.
If the recipe calls for partial grams, I do round down the lye and round up the oils. After all, some oil is always wasted on the soaping utensils despite my most earnest scraping efforts, as evidenced by the oily towels after wiping everything down at the end. Based on advice from many others here, I've lowered my initial SF from 7-8% down to 5%, and lately have been trying 3%. So far, I'm not seeing any difference in the soap feel, but am seeing less scum on the shower door. We don't have lots anyway, but any reduction in scum is good, IMO.
Most important is to figure out what works for your way of soaping, your recipes, etc., so that you end up with a consistently safe and usable soap. That may be rounding up, rounding down, ounces, or grams. Just be consistent in whatever you do (and take good notes). Then you have a lot less variables to weigh in order to figure out the problem if things do go wrong.
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Peachy Clean Soap
Well-Known Member
Wow' love your information & complete total understanding of soaping your knowledge is second to none' I so appreciate you taking the time to go into depth of explaining the differences & why above. Im going to save this info for future references'.
I've learned much & have much to learn on my journey of soaping.
Namaste
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tommysgirl
Well-Known Member
Wow' love your information & complete total understanding of soaping your knowledge is second to none' I so appreciate you taking the time to go into depth of explaining the differences & why above. Im going to save this info for future references'.
I've learned much & have much to learn on my journey of soaping.
Namaste
What she said!!
Thank you! 
It's not just the fat in goat milk (or other dairy) that consumes lye. Kevin Dunn and his students looked into the change in superfat when goat milk was used as a full replacement for water. They found using milk increased the superfat by an additional 4 to 6%. (Meaning if the water-only soap had 5% superfat, the milk-based soap had 9% to 11% superfat.)
Less than half of this increase is due to the lye reacting with the butterfat in the milk. The rest of the superfat increase is due to the lye also reacting with the sugar (lactose) in the milk.
To compensate for the effect of milk, Dunn suggested setting the superfat to zero when calculating a recipe that uses milk as the water-based liquid. The milk will add 4-6% to the superfat which is about right for what most people do.
We discussed this in more detail -- A few questions after a lot of reading
"...It made me wonder about using less super fat with other soaps. I use less than 20 coconut oil. Any suggestions whether I’m thinking ok or not would be appreciated.
In my opinion, a high superfat is useful to tame a strongly cleansing or harsh soap -- a soap high in myristic and lauric acids. That's why a 20% superfat is often used when making a "mariners" soap or a salt/brine soap that's mostly coconut oil.
For blends of fats that are moderate to low in myristic and lauric acids, it's been my observation that more superfat does not always mean the soap gets milder and milder. It's my guess that people often don't test the recipe with less superfat to see if it is mild enough to suit. They might be surprised if they did.
Another benefit of less superfat is the soap will lather better than the same soap with higher superfat, all other things being equal.
So, yeah, I think you're on the right track, although bear in mind my opinion is heresy with some soap makers.
"...essential oil blends that are less than a gram I’m stumped as to what to do...."
In this case, you do need the ability to weigh with 0.1 to 0.01 gram accuracy. That doesn't mean you have to spend lots of money, however. There are inexpensive light-duty "jeweler's scales" that can weigh up to, oh, about 300 grams or so. Used with care, an inexpensive high-precision scale is useful for accurately weighing small amounts of EOs, etc.
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Thank you Alioop. My note taking was bad, got better and still needs work. I'm going through my old notes now as my "soapy thing" and trying to sort them out. I appreciate your help.
My notes aren't the best, either. I've taken to leaving the recipe open in SMFriend, so that I can type a few quick words in the note section right before I pour the lye into the oils, and again after I've covered the soap. Otherwise, I can't find a writing utensil. at the moment, I think I'll be able to remember, but then don't even think about it again for months. Then it's like, what did I do on that batch again?
To compensate for the effect of milk, Dunn suggested setting the superfat to zero when calculating a recipe that uses milk as the water-based liquid. The milk will add 4-6% to the superfat which is about right for what most people do.
We discussed this in more detail -- A few questions after a lot of reading
"...It made me wonder about using less super fat with other soaps. I use less than 20 coconut oil. Any suggestions whether I’m thinking ok or not would be appreciated.
In my opinion, a high superfat is useful to tame a strongly cleansing or harsh soap -- a soap high in myristic and lauric acids. That's why a 20% superfat is often used when making a "mariners" soap or a salt/brine soap that's mostly coconut oil.
For blends of fats that are moderate to low in myristic and lauric acids, it's been my observation that more superfat does not always mean the soap gets milder and milder. It's my guess that people often don't test the recipe with less superfat to see if it is mild enough to suit. They might be surprised if they did.
Another benefit of less superfat is the soap will lather better than the same soap with higher superfat, all other things being equal.
So, yeah, I think you're on the right track, although bear in mind my opinion is heresy with some soap makers.
"...essential oil blends that are less than a gram I’m stumped as to what to do...."
In this case, you do need the ability to weigh with 0.1 to 0.01 gram accuracy. That doesn't mean you have to spend lots of money, however. There are inexpensive light-duty "jeweler's scales" that can weigh up to, oh, about 300 grams or so. Used with care, an inexpensive high-precision scale is useful for accurately weighing small amounts of EOs, etc.
I'm really terrible at this reply thing..I need to read up more how to condense replies.. among other things! I bought Kevin Dunn's book last year and as chemistry is not my strong point, I put it on my soap book shelf
It's very ironic I find another interest that taxes my brain more than my creativity but I intend to understand this. I'm going to slowly work my recipe down to 0% SF and see what happens. I'll also check amazon out for a jeweler's scale. I don't like guessing with the essential oils. I started out with 'teaspoons' and then I keep reading 
As for "heresy with some soap makers" you ALL puzzle me and impress me at the same time LOL. Take that as a compliment you experienced soapers!
that's a good idea. I'll give it a whirl. Anything to make it easier!
Peachy Clean Soap
Well-Known Member
Wonderful advise.Yup, exactly my recipe.
@Basil My scale doesn't do partial ounces, nor would I want to mess with that if it did. One gram is less than half an ounce, so measurements are far more precise using whole grams rather than whole ounces. And as @DeeAnna noted, errors are more likely when working with mixed units and decimal points.
If the recipe calls for partial grams, I do round down the lye and round up the oils. After all, some oil is always wasted on the soaping utensils despite my most earnest scraping efforts, as evidenced by the oily towels after wiping everything down at the end. Based on advice from many others here, I've lowered my initial SF from 7-8% down to 5%, and lately have been trying 3%. So far, I'm not seeing any difference in the soap feel, but am seeing less scum on the shower door. We don't have lots anyway, but any reduction in scum is good, IMO.
Most important is to figure out what works for your way of soaping, your recipes, etc., so that you end up with a consistently safe and usable soap. That may be rounding up, rounding down, ounces, or grams. Just be consistent in whatever you do (and take good notes). Then you have a lot less variables to weigh in order to figure out the problem if things do go wrong.
.
My little jeweler's scale which I paid $14 for is indispensable for making lotions. I have had it for at least 6 years and it is still going strong.
When I've made CP soap at zero to 1% superfat (and remember I also correct for purity), this soap can be faintly zappy at the time of unmolding. A mild zap is still an immediate "static shock" kind of sensation, but the sensation is dialed down to a whisper rather than a roar. The zap fades (edit: in the soap) after a day or two. (edit: The zap sensation fades on the tongue within seconds.)
I'm interpreting this as confirmation that my calculations are reasonably accurate -- the soap is on the edge of not-zappy and zappy, which is right where it should be if my zero superfat is really a zero superfat. I also have decided that 1% superfat is on the edge of not quite enough insurance for my preferences, but 2% superfat puts the soap firmly in the not-zappy category.
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Many times mine will be a tad zappy for a day or so after unmolding taking into account that I unmold in 8-10 hrs @ 1% superfat but has never stayed zappy any longer.
Peachy Clean Soap
Well-Known Member
Good points made especially "Like to bathe in soap not oils" Thought provoking. Im going to reduce SF to 3% make necessary adjustments needed.
I appreciate that. I don’t know if I’ll ever try anything but goat milk, but who knows? Whenever I say never it’s sure to happen. But I’m going to start with the one pound molds and try the same recipe with 3% and drop down each time until I get to 0. I really want to find the one that works the best for what I’m looking for. I’ve been ‘ gunho’ with all kinds of oils etc, but I’d like to narrow things down and start honing in. My husband just watches me ——surrounded by soap
Peachy Clean Soap
Well-Known Member
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.
