Same soap with two different results
I have a problem with the color of my soap that was poured into two different containers.
Some of the cold processed soap was poured into a Pringles chips container and rest was poured into kitchen silicone individual baking molds.
Both molds were then kept warm, keeping out the air. After 48 hours both were taken out, however, the Pringles soap is brown and the silicone baking soap is white.
Why is there a difference?
Is one better than the other?
Is soap in mold should be kept warm keeping the air out, right?
Gelled versus ungelled soap. Sometimes soap in one container will go through the gel phase while soap in another container will not. This will result in a difference of colour. The gelled soap will have a darker appearance and the ungelled soap will have a more chalk-like pastel look to it.
A few other things come to mind.
One...did you scent the two portions of soap base with different fragrance or essential oils? Some fragrances and essential oils will make the soap turn brown. Anything containing vanilla will often do this.
Two...did you line the Pringles tin? I haven't had them for a long time but I recall that the tins are lined with foil and perhaps the soap has reacted with the foil.
Three...did your soap contain milk? Milk will often cause soap to darken in colour. This is especially true if the soap has gone through the gel phase. In your case, the larger container of soap may have gelled while the smaller individual containers likely did not. The more soap in a container, the more likely a soap will gel. More mass equals more heat being generated and it's the heat that causes the gel phase. Some people place their milk soap in the refrigerator to prevent the gel phase from happening in order to have whiter milk soap.
It is not necessary to keep the air out. I wrap my soap because in my climate, it helps to keep the heat in to ensure my soap goes through the gel phase which is what I prefer.
In hotter climates, many people will not insulate their soap at all.
Both soaps should be just fine and neither is better than the other...just different in appearance.