scientific soapmaking - caveman chemistrycavemanchemistry.com/bcce2008b.pdf · why teach...
TRANSCRIPT
Scientific Soapmaking
Kevin M. Dunn
Summer 2008
$Revision: 1.1 $
1
Acknowledgements
Copyright © 2008 Kevin M. Dunn
Acknowledgements
• Mike Lawson/Columbus Foods
2
Why Teach Soapmaking?
Why Teach Soapmaking?
• Thriving cottage industry
Why Teach Soapmaking?
Why Teach Soapmaking?
• Thriving cottage industry
• Soapmakers generally come from a cooking/craft background
Why Teach Soapmaking?
Why Teach Soapmaking?
• Thriving cottage industry
• Soapmakers generally come from a cooking/craft background
• Soapmakers are interested in the chemistry of their craft
Why Teach Soapmaking?
Why Teach Soapmaking?
• Thriving cottage industry
• Soapmakers generally come from a cooking/craft background
• Soapmakers are interested in the chemistry of their craft
• If gen-ed students can imagine themselves as soapmakers, theywill become interested in the chemistry
Why Teach Soapmaking?
Why Teach Soapmaking?
• Thriving cottage industry
• Soapmakers generally come from a cooking/craft background
• Soapmakers are interested in the chemistry of their craft
• If gen-ed students can imagine themselves as soapmakers, theywill become interested in the chemistry
• Experiments are designed to solve real-world problems
Let’s Make Soap
Let’s Make Soap
• 100.00 g Delight (an oil blend)
• 28.80 g Lye (500 ppt NaOH)
Let’s Make Soap
Let’s Make Soap
• 100.00 g Delight (an oil blend)
• 28.80 g Lye (500 ppt NaOH)
• But how are we to weigh?
Weighing Synthetically
Weighing Synthetically
• Place cup of water on balance
• Press tare button
• Use pipet to transfer water to second cup
• What if we overshoot?
• What about the water in the pipet?
Let’s Make Soap
Let’s Make Soap
• 100.00 g Delight (already weighed)
• 28.80 g Lye (weigh synthetically into oil)
Let’s Make Soap
Let’s Make Soap
• 100.00 g Delight (already weighed)
• 28.80 g Lye (weigh synthetically into oil)
• Shake vigorously for 60 seconds
• Pour into styrofoam cup
• Measure temperature
Oil and Water
Oil and Water
Glyceryl Trilaurate
Glyceryl Trilaurate
O
O
O
O
O
O
Saponification
Saponification
Saponification
SaponificationNaOH
O
O
O
O
O
O
NaOH NaOH
↓
ONa
O
OH
OH
OH
ONa
O
ONa
O
Saponification
Saponification
• Oil + 3 NaOH = Glycerol + 3 Soap
• Each molecule of oil requires 3 molecules of NaOH
Saponification
Saponification
• Oil + 3 NaOH = Glycerol + 3 Soap
• Each molecule of oil requires 3 molecules of NaOH
• What happens if you provide only 2 molecules of NaOH?
Saponification
Saponification
• Oil + 3 NaOH = Glycerol + 3 Soap
• Each molecule of oil requires 3 molecules of NaOH
• What happens if you provide only 2 molecules of NaOH?
• What happens if you provide 4 molecules of NaOH?
Saponification
Saponification
• Oil + 3 NaOH = Glycerol + 3 Soap
• Each molecule of oil requires 3 molecules of NaOH
• What happens if you provide only 2 molecules of NaOH?
• What happens if you provide 4 molecules of NaOH?
• We measure oil and NaOH by weight, not by molecules
Saponification
Saponification
• Oil + 3 NaOH = Glycerol + 3 Soap
• Each molecule of oil requires 3 molecules of NaOH
• What happens if you provide only 2 molecules of NaOH?
• What happens if you provide 4 molecules of NaOH?
• We measure oil and NaOH by weight, not by molecules
• Each gram of oil should require a specific weight of NaOH forcomplete saponification
Saponification Value
Saponification ValueTheoretical saponification value of glyceryl tristearate:
? g KOH = 1000 g Oil(1 mol Oil890 g Oil
)(3 mol KOH1 mol Oil
)(56 g KOH
1 mol KOH
)= 189 ppt KOH
Experimental saponification value of tallow: 190-200 ppt
Saponification Value
Saponification ValueTheoretical sodium saponification value of glyceryl tristearate:
? g NaOH = 1000 g Oil(1 mol Oil890 g Oil
)(3 mol NaOH
1 mol Oil
)(40 g NaOH
1 mol NaOH
)= 135 ppt NaOH
Experimental sodium saponification value of tallow: 135-143 ppt
Saponification Value
Saponification Value
• SV = weight (mg) of KOH needed to saponify 1 g of oil
• SSV = weight (mg) of NaOH needed to saponify 1 g of oil
• AR = weight (mg) of alkali actually used to saponify 1 g of oil
Saponification Value
Saponification Value
• SV = weight (mg) of KOH needed to saponify 1 g of oil
• SSV = weight (mg) of NaOH needed to saponify 1 g of oil
• AR = weight (mg) of alkali actually used to saponify 1 g of oil
• SV of Delight is 211.5 ppt KOH
• SSV of Delight is 150.8 ppt NaOH
Saponification Value
Saponification Value
• SV = weight (mg) of KOH needed to saponify 1 g of oil
• SSV = weight (mg) of NaOH needed to saponify 1 g of oil
• AR = weight (mg) of alkali actually used to saponify 1 g of oil
• SV of Delight is 211.5 ppt KOH
• SSV of Delight is 150.8 ppt NaOH
• Since Lye is 500 ppt NaOH, we have used an AR of 144 pptNaOH
• Why?
Lye Discounting
Lye Discounting
0
2
4
6
140 144 148 152 156
Tota
l A
lkali
(p
pt
NaO
H)
Alkali Ratio (ppt NaOH)
1 Day Old
0
2
4
6
140 144 148 152 156
Tota
l A
lkali
(p
pt
NaO
H)
Alkali Ratio (ppt NaOH)
11 Weeks Old
Checking In
Checking InWhat are the temperature and consistency of your soap?
Measurable quantities
Measurable Quantities
• Finished soap• Total alkali• Moisture content• Hardness
Measurable quantities
Measurable Quantities
• Finished soap• Total alkali• Moisture content• Hardness
• Raw materials• Saponification value• Lye concentration• Free fatty acid
Free Fatty Acid
Free Fatty Acid
• Real-world oils may contain “free” fatty acid
• How can we measure it?
Titration
Titration
Titration
Titration
• Add 50 mL ethanol to Erlenmeyer flask
• Add 4-5 drops 1% phenolphthalein
• Add 4.18 ppt KOH until solution is faintly pink
• Solution is now “neutral”
Weighing Analytically
Weighing Analytically
• Place coconut oil bottle on balance
• Press tare button
• Transfer 30-40 drops of oil to Erlenmeyer flask
• Replace oil bottle on balance and read weight
Gravimetric Titration
Gravimetric Titration
• Place 4.18 ppt KOH bottle on balance
• Press tare button
• Add KOH to Erlenmeyer flask until faintly pink
• Replace KOH bottle on balance and read weight
Acid Value
Acid Value
? g KOH = 1000 g Oil(YY.YY g Std1.XX g Oil
)(4.ZZ g KOH1000 g Std
)=
(YY.YY1.XX
)4.ZZ ppt KOH
• What is the Acid Value of your oil?
Acid Value
Acid Value
? g KOH = 1000 g Oil(YY.YY g Std1.XX g Oil
)(4.ZZ g KOH1000 g Std
)=
(YY.YY1.XX
)4.ZZ ppt KOH
• What is the Acid Value of your oil?
• Why did we get different values?
Free Fatty Acid
Free Fatty Acid
• Free Lauric Acid = 3.570 AV
• What is the Free Lauric Acid content of your oil?
Free Fatty Acid
Free Fatty Acid
• Free Lauric Acid = 3.570 AV
• What is the Free Lauric Acid content of your oil?
• Which oil would saponify quicker?
Extended Investigations
Extended Investigations
• Dreaded Orange Spots
Extended Investigations
Extended Investigations
• Dreaded Orange Spots
• Seizing
Extended Investigations
Extended Investigations
• Dreaded Orange Spots
• Seizing
• Superfatting vs Discounting
Extended Investigations
Extended Investigations
• Dreaded Orange Spots
• Seizing
• Superfatting vs Discounting
• The Water “Discount”
Lye Concentration
Lye Concentration
• What is the normal, correct, or standard lye concentration?
Lye Concentration
Lye Concentration
• What is the normal, correct, or standard lye concentration?
• Ann Bramson, Soap: Making it, Enjoying it (1972)
25-27%, 26% average
Lye Concentration
Lye Concentration
• What is the normal, correct, or standard lye concentration?
• Ann Bramson, Soap: Making it, Enjoying it (1972)
25-27%, 26% average
• Susan Cavitch, The Soapmaker’s Companion (1997)
26-29%, 27% average
Lye Concentration
Lye Concentration
• What is the normal, correct, or standard lye concentration?
• Ann Bramson, Soap: Making it, Enjoying it (1972)
25-27%, 26% average
• Susan Cavitch, The Soapmaker’s Companion (1997)
26-29%, 27% average
• Robert McDaniel, Essentially Soap (2000)
33-38%, 34% average
Lye Concentration
Lye Concentration
• What is the normal, correct, or standard lye concentration?
• Ann Bramson, Soap: Making it, Enjoying it (1972)
25-27%, 26% average
• Susan Cavitch, The Soapmaker’s Companion (1997)
26-29%, 27% average
• Robert McDaniel, Essentially Soap (2000)
33-38%, 34% average
• Anne Watson, Smart Soapmaking (2007)
30-37%, 33% average
The Soap Formula
The Soap Formula
• Lye = 50.00% NaOH, 50.00% distilled water
• Coconut1000Lye348
Coconut1000Lye348Aq174
Coconut1000Lye348Aq348
The Soap Formula
The Soap Formula
• Lye = 50.00% NaOH, 50.00% distilled water
• Coconut1000Lye348 (50.00% NaOH “Low-Water”)
Coconut1000Lye348Aq174 (33.33% NaOH “Medium-Water”)
Coconut1000Lye348Aq348 (25.00% NaOH “High-Water”)
Processing Soap
Processing Soap
• 100 g oil + water + lye into 500 mL plastic bottle
• Shaken 15 sec on a paint shaker
• Gently swirled until trace
• Poured into an Upland experimental mold
• Incubated at 140◦F for 4 hours
Questions
Questions
• What do we want to know?
Questions
Questions
• What do we want to know?
• Does the initial water portion affect the final moisture content?
• Does it affect the curing time?
• Does it effect the hardness of the soap?
• Is there a danger of separation?
What Can We Measure?
What Can We Measure?
• Moisture content of soap over time
• Hardness of soap over time
• Alkalinity of soap over time
• Separation of soap
What Can We Measure?
What Can We Measure?
• Moisture content of soap over time
Initially from formula, follow weight loss over time
• Hardness of soap over time
• Alkalinity of soap over time
• Separation of soap
What Can We Measure?
What Can We Measure?
• Moisture content of soap over time
Initially from formula, follow weight loss over time
• Hardness of soap over time
Soil penetrometer
• Alkalinity of soap over time
• Separation of soap
What Can We Measure?
What Can We Measure?
• Moisture content of soap over time
Initially from formula, follow weight loss over time
• Hardness of soap over time
Soil penetrometer
• Alkalinity of soap over time
Titration with 5 ppt citric acid
• Separation of soap
What Can We Measure?
What Can We Measure?
• Moisture content of soap over time
Initially from formula, follow weight loss over time
• Hardness of soap over time
Soil penetrometer
• Alkalinity of soap over time
Titration with 5 ppt citric acid
• Separation of soap
Hardness of top and bottom of bar
Alkalinity of top and bottom of bar
Moisture
Moisture
• Coconut1000Lye348Aq348
• Total weight 1696 g
• Water weight (174 + 348) = 522 g
• Initial moisture = (522/1696) = 0.308 = 30.8% = 308 ppt
Moisture
Moisture
• Coconut1000Lye348Aq348
• Total weight 1696 g
• Water weight (174 + 348) = 522 g
• Initial moisture = (522/1696) = 0.308 = 30.8% = 308 ppt
• Initial bar weight 141.32 g; Final weight 113.17 g
• Weight loss (28.15/141.32) = 0.199 = 19.9% = 199 ppt
• Final moisture = 308 - 199 = 109 ppt
Penetrometer
Penetrometer
Smaller foot used for hard soaps.
Titration
Titration
How many grams of acid required to titrate a given weight ofsoap?
Total Alkali
Total Alkali
? g NaOH = 1000 g Soap(Y.YY g Acid1.XX g Soap
)(5 g H3Cit
1000 g Acid
)(
1 mol H3Cit192.12 g H3Cit
)(3 mol NaOH1 mol H3Cit
)(40.00 g NaOH1 mol NaOH
)= 3.123
(Y.YY1.XX
)ppt NaOH
Palm Oil
Palm Oil
• Low, Medium, and High Water soaps
• Identical in other respects
• Moisture and hardness measured weekly for 60 days
• Alkalinity measured at beginning and end
Palm Oil
Palm OilBatch Code Moisture/ppt Alkali/ppt NaOH
KMD2007.12.27 Initial Final Initial Final
Top Bottom Top Bottom
A Palm1000Lye286 111 54 1.8 4.9 0.3 0.9
B Palm1000Lye286Aq143 200 60 1.8 1.4 -1.7 -0.2
C Palm1000Lye286Aq286 273 74 0.5 0.3 -1.7 -0.1
0
100
200
300
0 30 60
pp
t
Days
Moisture
ABC
0
5
10
0 30 60
kg/s
cm
Days
Hardness
Coconut Oil
Coconut OilBatch Code Moisture/ppt Alkali/ppt NaOH
KMD2008.1.8 Initial Final Initial Final
Top Bottom Top Bottom
D Coconut1000Lye348 129 41 0.4 0.5 -0.6 -0.3
E Coconut1000Lye348Aq174 229 88 -0.1 -0.2 -1.7 -1.0
F Coconut1000Lye348Aq348 308 109 0.1 0.2 -1.8 -0.4
0
100
200
300
0 30 60
pp
t
Days
Moisture
DEF
0
5
10
0 30 60
kg/s
cm
Days
Hardness
Olive Oil
Olive Oil
• Medium and high water soaps separated
• What can I do to accelerate trace?
Olive Oil
Olive Oil
• Medium and high water soaps separated.
• What can I do to accelerate trace? Add clove oil.
Olive Oil
Olive OilBatch Code Moisture/ppt Alkali/ppt NaOH
KMD2008 Initial Final Initial Final
Top Bottom Top Bottom
1.7A Olive1000Lye264 104 36 0.3 0.2 -3.2 -0.4
3.5A Olive990Clove10Lye259 103 43 -0.4 -0.7 -0.7 -0.7
3.5B Olive990Clove10Lye259Aq130 187 61 -0.4 -0.4 -0.8 -0.7
3.5C Olive990Clove10Lye260Aq260 256 67 -0.7 6.2 -1.1 -0.2
0
100
200
300
0 30 60
pp
t
Days
Moisture
1.7A3.5A3.5B3.5C
0
5
10
0 30 60
kg/s
cm
Days
Hardness
Delight
Delight
• Delight = Olive390Palm280Coconut280Castor50
Delight
Delight
Batch Code Moisture/ppt Alkali/ppt NaOH
KMD2008.2.17 Initial Final Initial Final
Top Bottom Top Bottom
A Delight1000Lye288 112 48 -0.2 0.2 -1.0 -0.4
B Delight1000Lye288Aq144 201 89 -0.4 0.3 -3.1 -0.9
C Delight1000Lye288Aq288 274 104 -0.9 0.9 -3.7 -1.3
0
100
200
300
0 30 60
pp
t
Days
Moisture
ABC
0
5
10
0 30 60
kg/s
cm
Days
Hardness
Delight
Gel Phase
• Delight1000Lye288Aq50
Tmax 151◦F after 180 minutes
Never reached gel phase
Total alkali: 1.3 ppt (top), -0.2 ppt (bottom)
Delight
Gel Phase
• Delight1000Lye288Aq50
Tmax 151◦F after 180 minutes
Never reached gel phase
Total alkali: 1.3 ppt (top), -0.2 ppt (bottom)
• Delight1000Lye288Aq100
Tmax 156◦F after 165 minutes
“Very dry vaseline” at 145◦F after 210 minutes
Total alkali: 0.5 ppt (top), 0.1 ppt (bottom)
Delight
Gel Phase
• Delight1000Lye288Aq200
“Vaseline” with beads of oil at 151◦F after 195 minutes
Tmax 154◦F after 210 minutes
Total alkali: -0.2 ppt (top), 4.0 ppt (bottom)
Delight
Gel Phase
• Delight1000Lye288Aq200
“Vaseline” with beads of oil at 151◦F after 195 minutes
Tmax 154◦F after 210 minutes
Total alkali: -0.2 ppt (top), 4.0 ppt (bottom)
• Delight1000Lye288Aq250
Tmax 156◦F after 165 minutes
“Jello” with layer of oil at 156◦F after 180 minutes
Total alkali: -0.2 ppt (top), 8.7 ppt (bottom)
Conclusions
Conclusions
• I encountered no problems with lye concentrations up to 50%.
Conclusions
Conclusions
• I encountered no problems with lye concentrations up to 50%.
• High-water Olive and Delight soaps separated.
Conclusions
Conclusions
• I encountered no problems with lye concentrations up to 50%.
• High-water Olive and Delight soaps separated.
• More water delays trace.
Conclusions
Conclusions
• I encountered no problems with lye concentrations up to 50%.
• High-water Olive and Delight soaps separated.
• More water delays trace.
• Low-water soaps start out hard; medium- and high-water soapsmay or may not “catch up.”
Conclusions
Conclusions
• I encountered no problems with lye concentrations up to 50%.
• High-water Olive and Delight soaps separated.
• More water delays trace.
• Low-water soaps start out hard; medium- and high-water soapsmay or may not “catch up.”
• “Gel phase” was observed only for medium- and high-watersoaps. Since all soaps were fully saponified, gel phase is not es-sential. In fact, when separation occurred, it always happenedduring gel phase.
Conclusions
Conclusions
• I encountered no problems with lye concentrations up to 50%.
• High-water Olive and Delight soaps separated.
• More water delays trace.
• Low-water soaps start out hard; medium- and high-water soapsmay or may not “catch up.”
• “Gel phase” was observed only for medium- and high-watersoaps. Since all soaps were fully saponified, gel phase is not es-sential. In fact, when separation occurred, it always happenedduring gel phase.
• Saponification and curing are two separate processes.
Recommendations
Recommendations
• Decide on a standard lye concentration and always use thatwhen making soap.
Recommendations
Recommendations
• Decide on a standard lye concentration and always use thatwhen making soap.
• You can always add extra (water, milk, etc.) to delay trace ordecrease initial hardness.
Recommendations
Recommendations
• Decide on a standard lye concentration and always use thatwhen making soap.
• You can always add extra (water, milk, etc.) to delay trace ordecrease initial hardness.
• If oil separates from the soap, try decreasing the amount of (wa-ter, milk, etc.).
Recommendations
Recommendations
• Decide on a standard lye concentration and always use thatwhen making soap.
• You can always add extra (water, milk, etc.) to delay trace ordecrease initial hardness.
• If oil separates from the soap, try decreasing the amount of (wa-ter, milk, etc.).
• Be aware that soaps may continue to lose moisture, even after60 days.
Recommendations
Recommendations
• Decide on a standard lye concentration and always use thatwhen making soap.
• You can always add extra (water, milk, etc.) to delay trace ordecrease initial hardness.
• If oil separates from the soap, try decreasing the amount of (wa-ter, milk, etc.).
• Be aware that soaps may continue to lose moisture, even after60 days.
• Make lye only from NaOH and water.
Checking In
Checking InWhat are the temperature and consistency of your soap?
Summary
Why Am I Teaching You to TeachSoapmaking?
• There is a market for soapmaking instruction
Summary
Why Am I Teaching You to TeachSoapmaking?
• There is a market for soapmaking instruction
• Soapmaking can motivate gen-ed students
Summary
Why Am I Teaching You to TeachSoapmaking?
• There is a market for soapmaking instruction
• Soapmaking can motivate gen-ed students
• Online soapmaking communities are fraught with MSU
Summary
Why Am I Teaching You to TeachSoapmaking?
• There is a market for soapmaking instruction
• Soapmaking can motivate gen-ed students
• Online soapmaking communities are fraught with MSU
• I’m lonely
Summary
Organizations
• The Handcrafted Soap Makers Guild (www.SoapGuiild.org)
• The Saponifier (www.Saponifier.com)
• Scientific Soapmaking (www.ScientificSoapmaking.com)