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//-->SOAPMAKINGIntroductionWith practice, soapmaking is notdifficult and is suitable as a small-scale business. It uses simpleequipment and vegetable oils oranimal fats as raw materials, eachof which is likely to be locallyavailable in most countries.However, it is more difficult toproduce high-quality hard soap,which in some countries isnecessary to compete withimported products or thoseproduced by large-scalemanufacturers. There are alsocertain hazards in producingsoap, which any potentialproducer must be aware of toavoid injury. This technical briefdescribes the procedures neededto make a variety of simple soapsand includes a number of recipesfor different types of soap.Figure 1: Bina Baroi with some of her finished soap productsafter soapmaking training from Practical Action Bangladesh.Photo: Zul / Practical ActionIngredientsThere are three main ingredients in plain soap - oil or fat (oil is simply liquid fat), lye (or alkali)and water. Other ingredients may be added to give the soap a pleasant odour or colour, or toimprove its skin-softening qualities. Almost any fat or non-toxic oil is suitable for soapmanufacture. Common types include animal fat, avocado oil and sunflower oil. Lyes caneither be bought as potassium hydroxide (caustic potash) or from sodium hydroxide (causticsoda), or if they are not available, made from ashes. Some soaps are better made using softwater, and for these it is necessary to either use rainwater or add borax to tap water. Each ofthe above chemicals is usually available from pharmacies in larger towns.Caution!Lyes are extremely caustic. They cause burns if splashed on the skin and can causeblindness if splashed in the eye. If drunk, they can be fatal.Care is needed when handling lyes and ‘green’ (uncured) soap. Details of the precautionsthat should be taken are given below.Because of these dangers, keep small children away from the processing room while soap isbeing made.How to make lye from ashesCommercial lyes can be bought in tins from pharmacies in larger towns, and these are astandard strength to give consistent results. However, if they are not available or affordable,lye can also be made from ashes. Fit a tap near to the bottom of a large (e.g. 250 litre) plasticor wooden barrel/tub. Do not use aluminium because the lye will corrode it and the soap willbe contaminated. Make a filter inside, around the tap hole, using several bricks or stonescovered with straw. Fill the tub with ashes and pour boiling water over them until water beginsto run from the tap. Then shut the tap and let the ashes soak. The ashes will settle to lessSoapmakingPractical Actionthan one quarter of their original volume, and as they settle, add more ashes until the tub isfull again. Ashes from any burned plant material are suitable, but those from bananaleaf/stem make the strongest lye, and those from apple wood make the whitest soap.If a big barrel is not available, or smaller amounts of soap are to be made, a porcelain bowlor plastic bucket can be used. Fill the bucket with ashes and add boiling water, stirring to wetthe ashes. Add more ashes to fill the bucket to the top, add more water and stir again. Letthem stand for 12 - 24 hours, or until the liquid is clear, then carefully pour off the clear lye.The longer the water stands before being drawn off, the stronger the lye will be. Usually a fewhours will be enough. Lye that is able to cause a fresh egg to float can be used as a standardstrength for soap-making. The strength of the lye does not need to always be the same,because it combines with the fat in a fixed proportion. If a weak lye is used, more lye can be1added during the process until all the fat is saponified .How to make potashPotash is made by boiling down the lye water in a heavy iron kettle. After the water is drivenoff, a dark, dry residue known as ‘black salts’ remains. This is then heated until it melts andthe black impurities are burned away to leave a greyish-white substance. This is potash. Itcan be stored for future soapmaking in a moisture-proof pot to prevent it absorbing waterfrom the air.How to make soda lye and caustic sodaMix 1 part quicklime with 3 parts water to make a liquid that has the consistency of cream.Dissolve 3 parts sal soda in 5 parts boiling water, and add the lime cream, stirring vigorously.Keep the mixture boiling until the ingredients are thoroughly mixed. Then allow it to cool andsettle, and pour off the lye. Discard the dregs in the bottom. Caustic soda is produced byboiling down the lye until the water is evaporated and a dry, white residue is left in the kettle.Most commercial lyes are caustic soda, and these can be bought and substituted for home-made lye to save time. They are supplied in tins and the lids should be kept tightly fitted tostop the lye absorbing water from the air and forming a solid lump.Care when using lyes, potash or caustic sodaYou should always take precautions when handling these materials as they are dangerous.Be especially careful when adding them to cold water, when stirring lye water, and whenpouring the liquid soap into moulds. Lyes produce harmful fumes, so stand back and avertyour head while the lye is dissolving. Do not breath lye fumes. It is worth investing in a pairof rubber gloves and plastic safety goggles. You should also wear an apron or overalls toprotect your clothes. If lye splashes onto the skin or into your eyes, wash it off immediatelywith plenty of cold water.When lye is added to water the chemical reaction quickly heats the water. Never add lye tohot water because it can boil over and scald your skin. Never add water to lye because itcould react violently and splash over you.How to prepare tallowCut up beef suet, mutton fat or pork scraps and heat them over a low heat. Strain the meltedfat through a coarse cloth, and squeeze as much fat as possible out of the scraps.Clean the melted fat by boiling it in water. Use twice as much water as fat, add a tablespoonof salt per 5 kg fat, and boil for ten minutes, stirring thoroughly all the time. Allow it to cooland form a hard cake on top of the water. Lift off the cake of fat and scrape the undersideclean. This is then ready to store or use in a soap recipe.saponification is the name given to the chemical reaction in which lye and fat are converted into one substance -soap12SoapmakingPractical ActionHow to prepare oilVegetable oils can be extracted from oilseeds, nuts or some types of fruit (see Table 1 andthe separate Technical Brief ‘Oil Extraction’). They can be used alone or mixed with fat orother types of oil. Note: solid fats and ‘saturated’ oils (coconut, palm, palm kernel) are moresuitable for soapmaking. ‘Unsaturated’ oils (e.g. safflower, sunflower) may produce soap thatis too soft if used alone (see Table 2) and are not recommended.SoapmakingThere are two types of soap: soft soap and hard soap. Soft soap can be made using either acold process or a hot process, but hard soap can only be made using a hot process. Tomake any soap it is necessary to dilute the lye, mix it with the fat or oil, and stir the mixtureuntil saponification takes place (in the processes described below, the word ‘fat’ is used tomean either fat or oil). The cold process may require several days or even months,depending upon the strength and purity of the ingredients, whereas the hot process takesplace within a few minutes to a few hours.Dispose of soap-making wastes carefully outdoors, do not put them in the drain.FatsOilsGoat fatCanolaLanolinCoconutLardCottonseedMutton fatPalmPork fatPalm kernelSuetSoybeanTallowTable 1: Types of fats and oils used in soapmakingSoft soapCold processA simple recipe for soft soap uses 12 kg of fat, 9 kg of potash and 26 litres of water. Dissolvethe potash in the water and add it to the fat in a wooden tub or barrel. For the next 3 days, stirit vigorously for about 3 minutes several times a day, using a long wooden stick or paddle.Keep the paddle in the mixture to prevent anyone accidentally touching it and being burned.In a month or so the soap is free from lumps and has a uniform jelly-like consistency. Whenstirred it has a silky lustre and trails off the paddle in slender threads. Then the soap is readyto use and should be kept in a covered container.Boiling processSoft soap is also made by boiling diluted lye with fat until saponification takes place. Usingthe same amounts as above, put the fat into a soap kettle, add sufficient lye to melt the fatand heat it without burning. The froth that forms as the mixture cooks is caused by excesswater, and the soap must be heated until this is evaporated. Continue to heat and add morelye until all the fat is saponified. Beat the froth with the paddle and when it ceases to rise, thesoap falls lower in the kettle and takes on a darker colour. White bubbles appear on thesurface, making a peculiar sound (the soap is “talking”). The thick liquid then becomes turbidand falls from the paddle with a shining lustre. Further lye should then be added at regularintervals until the liquid becomes a uniformly clear slime. The soap is fully saponified when itis thick and creamy, with a slightly slimy texture. After cooling, it does not harden and is readyto use.To test whether the soap is properly made, put a few drops from the middle of the kettle ontoa plate to cool. If it remains clear when cool it is ready. However, if there is not enough lye thedrop of soap is weak and grey. If the deficiency is not so great, there may be a grey marginaround the outside of the drop. If too much lye has been added, a grey skin will spread overthe whole drop. It will not be sticky, but can be slid along the plate while wet. In this case thesoap is overdone and more fat must be added.3SoapmakingPractical ActionHard soapThe method for making hard soap is similar to that for making soft soap by the boilingprocess, but with additional steps to separate water, glycerine, excess alkali and otherimpurities from the soap. The method requires three kettles: two small kettles to hold the lyeand the fat, and one large enough to contain both ingredients without boiling over.Put the clean fat in a small kettle with enough water or weak lye to prevent burning, and raisethe temperature to boiling. Put the diluted lye in the other small kettle and heat it to boiling.Heat the large kettle, and ladle in about one quarter of the melted fat. Add an equal amountof the hot lye, stirring the mixture constantly. Continue this way, with one person ladling andanother stirring, until about two-thirds of the fat and lye have been thoroughly mixed together.At this stage the mixture should be uniform with the consistency of cream. A few dropscooled on a glass plate should show neither separate globules of oil or water droplets.Continue boiling and add the remainder of the fat and lye alternately, taking care that there isno excess lye at the end of the process. Boiled hard soaps have saponified when the mixtureis thick and ropy and slides off the paddle.Up to this point, the process is similar to boiling soft soap, but the important difference inmaking hard soap is the addition of salt at this point. This is the means by which the creamyemulsion of oils and lye is broken up. The salt has a stronger affinity for water than it has forsoap, and it therefore takes the water and causes the soap to separate. The soap then risesto the surface of the lye in curdy granules. The spent lye contains glycerine, salt and otherimpurities, but no fat or alkali. Pour the honey-thick mixture into soap moulds or shallowwooden boxes, over which loose pieces of cloth have been placed to stop the soap fromsticking. Alternatively, the soap may be poured into a tub which has been soaked overnight inwater, to cool and solidify. Do not use an aluminium container because the soap will corrodeit. Cover the moulds or tub with sacks to keep the heat in, and let it set for 2 - 3 days.When cold the soap may be cut into smaller bars with a smooth, hard cord or a fine wire. It ispossible to use a knife, but care is needed because it chips the soap. Stack the bars looselyon slatted wooden shelves in a cool, dry place and leave them for at least 3 weeks to seasonand become thoroughly dry and hard.Be careful! Uncured or ‘green’ soap is almost as caustic as lye. Wear rubber gloveswhen handling the hardened soap until it has been cured for a few weeks.Problems in soapmakingProblems that can occur in soapmaking and their possible causes are described in Table 2.ProblemSoap will not thicken quicklyenoughMixture curdles while stirringMixture sets too quickly, while inthe kettleMixture is grainyLayer of oil forms on soap as itcoolsClear liquid in soap when it is cutSoft spongy soapHard brittle soapSoap smells rancidAir bubbles in soapMottled soapPossible causesNot enough lye, too much water, temperature too low, notstirred enough or too slowly, too much unsaturated oil (e.g.sunflower or safflower).Fat and/or lye at too high temperature, not stirred enough ortoo slowly.Fat and lye temperatures too high.Fat and lye temperature too hot or too cold, not stirred enoughor too slowly.Too much fat in recipe or not enough lye.Too much lye in recipe, not stirred enough or too slowly.Not enough lye, too much water, or too much unsaturated oilToo much lyePoor quality fat, too much fat or not enough lye.Stirred too longNot stirred enough or too slowly or temperature fluctuations4SoapmakingPractical ActionSoap separates in mould, greasysurface layer on soapWhite powder on cured soapWarped barsTable 2: Problems in soapmaking(Adapted from websitewww.colebrothers.com/soapin list of further information below)during curing.Not enough lye, not boiled for long enough, not stirred enoughor too slowlyHard water, lye not dissolved properly, reaction with air.Drying conditions variable.To improve hard soapA better quality soap may be made by re-melting the product of the first boiling and addingmore fats or oils and lye as needed, then boil the whole until saponification is complete. Thetime required for this final step will depend on the strength of the lye, but 2 - 4 hours’ boiling isusually necessary. If pure grained fat and good quality white lye are used, the resultingproduct will be a pure, hard white soap that is suitable for all household purposes. Dyes,essences or essential oils can be added to the soap at the end of the boiling to colour it or tomask the ‘fatty lye’ smell and give a pleasant odour.Hard soap recipesThe simplest and cheapest type of soap is plain laundry soap, but a few inexpensiveingredients can be used to soften the water or to perfume the product and create fine toiletsoaps too. The following recipes are a few examples of easily made soaps. There are manymore recipes in the information sources given at the end of this Technical Brief.Simple kitchen soapDissolve 1 can of commercial lye in 5 cups cold water and allow it to cool. Meanwhile mix 2tablespoons each of powdered borax and liquid ammonia in �½ cup water. Melt 3 kg fat, strainit and allow it to cool to body temperature. Pour the warm fat into the lye water and whilebeating the mixture, gradually add the borax and ammonia mixture. Stir for about 10 - 15minutes until an emulsion is formed, and pour the mixture into a mould to cool.Boiled hard white soapDissolve 0.5 kg potash lye in5litres of cold water. Let mixture stand overnight, then pour theclear liquid into a second 5 litres of hot water and bring it to a boil. Pour in 2 kg of hot meltedfat in a thin stream, stirring constantly until an emulsion is formed. Simmer for 4 - 6 hourswith regular stirring, and then add5litres of hot water in which 1 cup of salt is dissolved. Testto ensure that the mixture is saponified by lifting it on a cold knife blade, to ensure that it isropy and clear.orDissolve 0.5 kg potash in 2 litres of cold water. Heat and add 2.5 kg melted fat, stirringconstantly. Let the mixture stand for 24 hours and add 5 litres boiling water. Place it on a lowheat and boil with constant stirring until it is saponified.Labour-saving soapDissolve 0.5 kg soda lye and 1 kg yellow bar soap cut into thin slices in 12 litres of water. Boilfor 2 hours and then strain. Clothes soaked overnight in a solution of this soap need norubbing. Merely rinse them out and they will be clean and white.English bar soapUse 5 litres of soft water, 0.5 kg of ground (or agricultural) lime, 1.75 kg soda lye, 30g borax,1 kg tallow, 0.7 kg pulverised rosin and 14g beeswax. First bring the water to a boil, and thengradually add the lime and soda, stirring vigorously. Add the borax, boil and stir until it isdissolved. Pour in the melted tallow in a thin stream, stirring constantly. Add the rosin andbeeswax, and boil and stir until it thickens. Cool in moulds.Transparent soapAny good quality white soap may be made transparent by reducing it to shavings, adding onepart alcohol to 2 parts soap, and leaving the mixture in a warm place until the soap isdissolved. It may be perfumed as desired.5 [ Pobierz całość w formacie PDF ]
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//-->SOAPMAKINGIntroductionWith practice, soapmaking is notdifficult and is suitable as a small-scale business. It uses simpleequipment and vegetable oils oranimal fats as raw materials, eachof which is likely to be locallyavailable in most countries.However, it is more difficult toproduce high-quality hard soap,which in some countries isnecessary to compete withimported products or thoseproduced by large-scalemanufacturers. There are alsocertain hazards in producingsoap, which any potentialproducer must be aware of toavoid injury. This technical briefdescribes the procedures neededto make a variety of simple soapsand includes a number of recipesfor different types of soap.Figure 1: Bina Baroi with some of her finished soap productsafter soapmaking training from Practical Action Bangladesh.Photo: Zul / Practical ActionIngredientsThere are three main ingredients in plain soap - oil or fat (oil is simply liquid fat), lye (or alkali)and water. Other ingredients may be added to give the soap a pleasant odour or colour, or toimprove its skin-softening qualities. Almost any fat or non-toxic oil is suitable for soapmanufacture. Common types include animal fat, avocado oil and sunflower oil. Lyes caneither be bought as potassium hydroxide (caustic potash) or from sodium hydroxide (causticsoda), or if they are not available, made from ashes. Some soaps are better made using softwater, and for these it is necessary to either use rainwater or add borax to tap water. Each ofthe above chemicals is usually available from pharmacies in larger towns.Caution!Lyes are extremely caustic. They cause burns if splashed on the skin and can causeblindness if splashed in the eye. If drunk, they can be fatal.Care is needed when handling lyes and ‘green’ (uncured) soap. Details of the precautionsthat should be taken are given below.Because of these dangers, keep small children away from the processing room while soap isbeing made.How to make lye from ashesCommercial lyes can be bought in tins from pharmacies in larger towns, and these are astandard strength to give consistent results. However, if they are not available or affordable,lye can also be made from ashes. Fit a tap near to the bottom of a large (e.g. 250 litre) plasticor wooden barrel/tub. Do not use aluminium because the lye will corrode it and the soap willbe contaminated. Make a filter inside, around the tap hole, using several bricks or stonescovered with straw. Fill the tub with ashes and pour boiling water over them until water beginsto run from the tap. Then shut the tap and let the ashes soak. The ashes will settle to lessSoapmakingPractical Actionthan one quarter of their original volume, and as they settle, add more ashes until the tub isfull again. Ashes from any burned plant material are suitable, but those from bananaleaf/stem make the strongest lye, and those from apple wood make the whitest soap.If a big barrel is not available, or smaller amounts of soap are to be made, a porcelain bowlor plastic bucket can be used. Fill the bucket with ashes and add boiling water, stirring to wetthe ashes. Add more ashes to fill the bucket to the top, add more water and stir again. Letthem stand for 12 - 24 hours, or until the liquid is clear, then carefully pour off the clear lye.The longer the water stands before being drawn off, the stronger the lye will be. Usually a fewhours will be enough. Lye that is able to cause a fresh egg to float can be used as a standardstrength for soap-making. The strength of the lye does not need to always be the same,because it combines with the fat in a fixed proportion. If a weak lye is used, more lye can be1added during the process until all the fat is saponified .How to make potashPotash is made by boiling down the lye water in a heavy iron kettle. After the water is drivenoff, a dark, dry residue known as ‘black salts’ remains. This is then heated until it melts andthe black impurities are burned away to leave a greyish-white substance. This is potash. Itcan be stored for future soapmaking in a moisture-proof pot to prevent it absorbing waterfrom the air.How to make soda lye and caustic sodaMix 1 part quicklime with 3 parts water to make a liquid that has the consistency of cream.Dissolve 3 parts sal soda in 5 parts boiling water, and add the lime cream, stirring vigorously.Keep the mixture boiling until the ingredients are thoroughly mixed. Then allow it to cool andsettle, and pour off the lye. Discard the dregs in the bottom. Caustic soda is produced byboiling down the lye until the water is evaporated and a dry, white residue is left in the kettle.Most commercial lyes are caustic soda, and these can be bought and substituted for home-made lye to save time. They are supplied in tins and the lids should be kept tightly fitted tostop the lye absorbing water from the air and forming a solid lump.Care when using lyes, potash or caustic sodaYou should always take precautions when handling these materials as they are dangerous.Be especially careful when adding them to cold water, when stirring lye water, and whenpouring the liquid soap into moulds. Lyes produce harmful fumes, so stand back and avertyour head while the lye is dissolving. Do not breath lye fumes. It is worth investing in a pairof rubber gloves and plastic safety goggles. You should also wear an apron or overalls toprotect your clothes. If lye splashes onto the skin or into your eyes, wash it off immediatelywith plenty of cold water.When lye is added to water the chemical reaction quickly heats the water. Never add lye tohot water because it can boil over and scald your skin. Never add water to lye because itcould react violently and splash over you.How to prepare tallowCut up beef suet, mutton fat or pork scraps and heat them over a low heat. Strain the meltedfat through a coarse cloth, and squeeze as much fat as possible out of the scraps.Clean the melted fat by boiling it in water. Use twice as much water as fat, add a tablespoonof salt per 5 kg fat, and boil for ten minutes, stirring thoroughly all the time. Allow it to cooland form a hard cake on top of the water. Lift off the cake of fat and scrape the undersideclean. This is then ready to store or use in a soap recipe.saponification is the name given to the chemical reaction in which lye and fat are converted into one substance -soap12SoapmakingPractical ActionHow to prepare oilVegetable oils can be extracted from oilseeds, nuts or some types of fruit (see Table 1 andthe separate Technical Brief ‘Oil Extraction’). They can be used alone or mixed with fat orother types of oil. Note: solid fats and ‘saturated’ oils (coconut, palm, palm kernel) are moresuitable for soapmaking. ‘Unsaturated’ oils (e.g. safflower, sunflower) may produce soap thatis too soft if used alone (see Table 2) and are not recommended.SoapmakingThere are two types of soap: soft soap and hard soap. Soft soap can be made using either acold process or a hot process, but hard soap can only be made using a hot process. Tomake any soap it is necessary to dilute the lye, mix it with the fat or oil, and stir the mixtureuntil saponification takes place (in the processes described below, the word ‘fat’ is used tomean either fat or oil). The cold process may require several days or even months,depending upon the strength and purity of the ingredients, whereas the hot process takesplace within a few minutes to a few hours.Dispose of soap-making wastes carefully outdoors, do not put them in the drain.FatsOilsGoat fatCanolaLanolinCoconutLardCottonseedMutton fatPalmPork fatPalm kernelSuetSoybeanTallowTable 1: Types of fats and oils used in soapmakingSoft soapCold processA simple recipe for soft soap uses 12 kg of fat, 9 kg of potash and 26 litres of water. Dissolvethe potash in the water and add it to the fat in a wooden tub or barrel. For the next 3 days, stirit vigorously for about 3 minutes several times a day, using a long wooden stick or paddle.Keep the paddle in the mixture to prevent anyone accidentally touching it and being burned.In a month or so the soap is free from lumps and has a uniform jelly-like consistency. Whenstirred it has a silky lustre and trails off the paddle in slender threads. Then the soap is readyto use and should be kept in a covered container.Boiling processSoft soap is also made by boiling diluted lye with fat until saponification takes place. Usingthe same amounts as above, put the fat into a soap kettle, add sufficient lye to melt the fatand heat it without burning. The froth that forms as the mixture cooks is caused by excesswater, and the soap must be heated until this is evaporated. Continue to heat and add morelye until all the fat is saponified. Beat the froth with the paddle and when it ceases to rise, thesoap falls lower in the kettle and takes on a darker colour. White bubbles appear on thesurface, making a peculiar sound (the soap is “talking”). The thick liquid then becomes turbidand falls from the paddle with a shining lustre. Further lye should then be added at regularintervals until the liquid becomes a uniformly clear slime. The soap is fully saponified when itis thick and creamy, with a slightly slimy texture. After cooling, it does not harden and is readyto use.To test whether the soap is properly made, put a few drops from the middle of the kettle ontoa plate to cool. If it remains clear when cool it is ready. However, if there is not enough lye thedrop of soap is weak and grey. If the deficiency is not so great, there may be a grey marginaround the outside of the drop. If too much lye has been added, a grey skin will spread overthe whole drop. It will not be sticky, but can be slid along the plate while wet. In this case thesoap is overdone and more fat must be added.3SoapmakingPractical ActionHard soapThe method for making hard soap is similar to that for making soft soap by the boilingprocess, but with additional steps to separate water, glycerine, excess alkali and otherimpurities from the soap. The method requires three kettles: two small kettles to hold the lyeand the fat, and one large enough to contain both ingredients without boiling over.Put the clean fat in a small kettle with enough water or weak lye to prevent burning, and raisethe temperature to boiling. Put the diluted lye in the other small kettle and heat it to boiling.Heat the large kettle, and ladle in about one quarter of the melted fat. Add an equal amountof the hot lye, stirring the mixture constantly. Continue this way, with one person ladling andanother stirring, until about two-thirds of the fat and lye have been thoroughly mixed together.At this stage the mixture should be uniform with the consistency of cream. A few dropscooled on a glass plate should show neither separate globules of oil or water droplets.Continue boiling and add the remainder of the fat and lye alternately, taking care that there isno excess lye at the end of the process. Boiled hard soaps have saponified when the mixtureis thick and ropy and slides off the paddle.Up to this point, the process is similar to boiling soft soap, but the important difference inmaking hard soap is the addition of salt at this point. This is the means by which the creamyemulsion of oils and lye is broken up. The salt has a stronger affinity for water than it has forsoap, and it therefore takes the water and causes the soap to separate. The soap then risesto the surface of the lye in curdy granules. The spent lye contains glycerine, salt and otherimpurities, but no fat or alkali. Pour the honey-thick mixture into soap moulds or shallowwooden boxes, over which loose pieces of cloth have been placed to stop the soap fromsticking. Alternatively, the soap may be poured into a tub which has been soaked overnight inwater, to cool and solidify. Do not use an aluminium container because the soap will corrodeit. Cover the moulds or tub with sacks to keep the heat in, and let it set for 2 - 3 days.When cold the soap may be cut into smaller bars with a smooth, hard cord or a fine wire. It ispossible to use a knife, but care is needed because it chips the soap. Stack the bars looselyon slatted wooden shelves in a cool, dry place and leave them for at least 3 weeks to seasonand become thoroughly dry and hard.Be careful! Uncured or ‘green’ soap is almost as caustic as lye. Wear rubber gloveswhen handling the hardened soap until it has been cured for a few weeks.Problems in soapmakingProblems that can occur in soapmaking and their possible causes are described in Table 2.ProblemSoap will not thicken quicklyenoughMixture curdles while stirringMixture sets too quickly, while inthe kettleMixture is grainyLayer of oil forms on soap as itcoolsClear liquid in soap when it is cutSoft spongy soapHard brittle soapSoap smells rancidAir bubbles in soapMottled soapPossible causesNot enough lye, too much water, temperature too low, notstirred enough or too slowly, too much unsaturated oil (e.g.sunflower or safflower).Fat and/or lye at too high temperature, not stirred enough ortoo slowly.Fat and lye temperatures too high.Fat and lye temperature too hot or too cold, not stirred enoughor too slowly.Too much fat in recipe or not enough lye.Too much lye in recipe, not stirred enough or too slowly.Not enough lye, too much water, or too much unsaturated oilToo much lyePoor quality fat, too much fat or not enough lye.Stirred too longNot stirred enough or too slowly or temperature fluctuations4SoapmakingPractical ActionSoap separates in mould, greasysurface layer on soapWhite powder on cured soapWarped barsTable 2: Problems in soapmaking(Adapted from websitewww.colebrothers.com/soapin list of further information below)during curing.Not enough lye, not boiled for long enough, not stirred enoughor too slowlyHard water, lye not dissolved properly, reaction with air.Drying conditions variable.To improve hard soapA better quality soap may be made by re-melting the product of the first boiling and addingmore fats or oils and lye as needed, then boil the whole until saponification is complete. Thetime required for this final step will depend on the strength of the lye, but 2 - 4 hours’ boiling isusually necessary. If pure grained fat and good quality white lye are used, the resultingproduct will be a pure, hard white soap that is suitable for all household purposes. Dyes,essences or essential oils can be added to the soap at the end of the boiling to colour it or tomask the ‘fatty lye’ smell and give a pleasant odour.Hard soap recipesThe simplest and cheapest type of soap is plain laundry soap, but a few inexpensiveingredients can be used to soften the water or to perfume the product and create fine toiletsoaps too. The following recipes are a few examples of easily made soaps. There are manymore recipes in the information sources given at the end of this Technical Brief.Simple kitchen soapDissolve 1 can of commercial lye in 5 cups cold water and allow it to cool. Meanwhile mix 2tablespoons each of powdered borax and liquid ammonia in �½ cup water. Melt 3 kg fat, strainit and allow it to cool to body temperature. Pour the warm fat into the lye water and whilebeating the mixture, gradually add the borax and ammonia mixture. Stir for about 10 - 15minutes until an emulsion is formed, and pour the mixture into a mould to cool.Boiled hard white soapDissolve 0.5 kg potash lye in5litres of cold water. Let mixture stand overnight, then pour theclear liquid into a second 5 litres of hot water and bring it to a boil. Pour in 2 kg of hot meltedfat in a thin stream, stirring constantly until an emulsion is formed. Simmer for 4 - 6 hourswith regular stirring, and then add5litres of hot water in which 1 cup of salt is dissolved. Testto ensure that the mixture is saponified by lifting it on a cold knife blade, to ensure that it isropy and clear.orDissolve 0.5 kg potash in 2 litres of cold water. Heat and add 2.5 kg melted fat, stirringconstantly. Let the mixture stand for 24 hours and add 5 litres boiling water. Place it on a lowheat and boil with constant stirring until it is saponified.Labour-saving soapDissolve 0.5 kg soda lye and 1 kg yellow bar soap cut into thin slices in 12 litres of water. Boilfor 2 hours and then strain. Clothes soaked overnight in a solution of this soap need norubbing. Merely rinse them out and they will be clean and white.English bar soapUse 5 litres of soft water, 0.5 kg of ground (or agricultural) lime, 1.75 kg soda lye, 30g borax,1 kg tallow, 0.7 kg pulverised rosin and 14g beeswax. First bring the water to a boil, and thengradually add the lime and soda, stirring vigorously. Add the borax, boil and stir until it isdissolved. Pour in the melted tallow in a thin stream, stirring constantly. Add the rosin andbeeswax, and boil and stir until it thickens. Cool in moulds.Transparent soapAny good quality white soap may be made transparent by reducing it to shavings, adding onepart alcohol to 2 parts soap, and leaving the mixture in a warm place until the soap isdissolved. It may be perfumed as desired.5 [ Pobierz całość w formacie PDF ]