ResolvableOwl
Notorious Lyear
Just another whacky over-engineering idea off my restless brain 
. A lot to read, nothing to see.
Soapmakers’ folklore knows: DOS is infectious.
Background: after some relatively tame incubation time, oxidative rancidity of unsaturated oils is a runaway chain reaction, and once it is in full progress (aka too late), it will produce yellow and orange coloured byproducts in substantial amounts (= DOS). This state of rapid decay starts at a few spots, and from there it spreads over the whole bar of soap, and can even jump from bar to bar, and “infect” bars that would otherwise have been rather safe from developing DOS by themselves.
The idea: Exploit the infectiousness of DOS to build a DOS detector, that can distinguish DOS from other things (like discolouring FOs), ideally also in early/uncertain cases. Also for orange-red or dark coloured soaps, and those strong-smelling soaps (high FO load, neem, laurel…) for which the nose is of little help to detect rancidity.
The concept/application: Small cubes (cm-sized or smaller) of an exceptionally DOS prone soap, made under lab conditions, and then vacuum sealed. For a test, you wrap open one of the bags, take out the soap cube, and press/stick/pin/wrap it tightly to the soap bar in question, and let it sit for some time. If the original bar has DOS, it should infect the test cube. Originating from the contact surface, the probe soap cube should develop DOS by itself. Some calibration has to be made beforehand to tell the specificity and speed of this reaction (hours? days? weeks?).
The recipe: Maxed out IV by a strategic blend of HL safflower, poppy seed and/or sacha inchi oil (not perilla, flaxseed, hemp or camelina, since these are too coloured by themselves), with their natural tocopherols and dyestuff carefully stripped as thoroughly as possible (RBD). Plus 30–40% hard soy wax (to end up with bar soap rather than alien slime). HP, with 5% of the high-IV oil added after cook. It doesn't have to be great soap, its purpose is in the lab, not at the sink.
No antioxidants/chelators added. Cured under elevated atmospheric security precautions. Sealed into diffusion barrier composite polybags in pairs (one for the actual test, one control bar to let age under same conditions). “Store in the freezer until needed”-class instructions.
tl;dr: When in doubt something might or might not be DOS, or when you want to test how “far away” some oldish recipe is from going rancid, grab one of these vacuumed cubes from your freezer, wrap it open, and stick it to the bar in question. Wait a few days, and see if it infected your test cube with DOS (turned yellow quicker than the control cubelet).
. A lot to read, nothing to see.Soapmakers’ folklore knows: DOS is infectious.
Background: after some relatively tame incubation time, oxidative rancidity of unsaturated oils is a runaway chain reaction, and once it is in full progress (aka too late), it will produce yellow and orange coloured byproducts in substantial amounts (= DOS). This state of rapid decay starts at a few spots, and from there it spreads over the whole bar of soap, and can even jump from bar to bar, and “infect” bars that would otherwise have been rather safe from developing DOS by themselves.
The idea: Exploit the infectiousness of DOS to build a DOS detector, that can distinguish DOS from other things (like discolouring FOs), ideally also in early/uncertain cases. Also for orange-red or dark coloured soaps, and those strong-smelling soaps (high FO load, neem, laurel…) for which the nose is of little help to detect rancidity.
The concept/application: Small cubes (cm-sized or smaller) of an exceptionally DOS prone soap, made under lab conditions, and then vacuum sealed. For a test, you wrap open one of the bags, take out the soap cube, and press/stick/pin/wrap it tightly to the soap bar in question, and let it sit for some time. If the original bar has DOS, it should infect the test cube. Originating from the contact surface, the probe soap cube should develop DOS by itself. Some calibration has to be made beforehand to tell the specificity and speed of this reaction (hours? days? weeks?).
The recipe: Maxed out IV by a strategic blend of HL safflower, poppy seed and/or sacha inchi oil (not perilla, flaxseed, hemp or camelina, since these are too coloured by themselves), with their natural tocopherols and dyestuff carefully stripped as thoroughly as possible (RBD). Plus 30–40% hard soy wax (to end up with bar soap rather than alien slime). HP, with 5% of the high-IV oil added after cook. It doesn't have to be great soap, its purpose is in the lab, not at the sink.
No antioxidants/chelators added. Cured under elevated atmospheric security precautions. Sealed into diffusion barrier composite polybags in pairs (one for the actual test, one control bar to let age under same conditions). “Store in the freezer until needed”-class instructions.
tl;dr: When in doubt something might or might not be DOS, or when you want to test how “far away” some oldish recipe is from going rancid, grab one of these vacuumed cubes from your freezer, wrap it open, and stick it to the bar in question. Wait a few days, and see if it infected your test cube with DOS (turned yellow quicker than the control cubelet).
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