CPOP questions!

[Katie68121]

Hello soapers!
So I want to try the oven process, but after watching many videos and reading posts about it I still have some unanswered questions.
1. Do I turn oven on to lowest setting, and then turn off right before I put the soap in? OR do I leave it on the lowest setting and leave ON for an hour, then turn off?
2. Uncovered or covered? Do I place wood or plastic wrap or towels on top of my mold or leave uncovered?
3. How long do I leave in the oven before taking out? Overnight? Then it’s ok to cut?
4. What is the best lye concentration %? I was going to go with 33%...
Thank you for you help and guidance!

 

[IrishLass]

Hi Katie! I do oven CPOP all the time.

1) This is what I do: After pouring my soap into the mold, I turn my oven on and let it heat up for 3 minutes and then turn it off as soon as I put my soap inside it and close the oven door.. For what it's worth, when first turned on, my oven's default temp is set to 350 degrees F. Letting it heat up on this default setting for a maximum of 3 minutes brings the temp of my oven up to 110 degrees F, which is my preferred CPOP temp.

2) I cover my mold. With my wooden mold, I cover with it's accompanying wooden cover and then further cover over that with a few cotton cloth diapers I have on hand. And with my silicone mold, I cover with plastic wrap, then on top of that I place an appropriately sized piece of cardboard and cover over that with a cotton diaper.

3) I soap at night, and so I just leave my soap in the oven and go to bed. I take it out about 18 hours later and unmold and cut into bars right away.

4) I soap with a 33% lye concentration, and my soaping temp is 110 degreesF. My CPOP method gives me fully gelled soap 99.9% of the time. Every once in a blue moon I'll get the rare batch that gels just short of the edges.


IrishLass

 

[TheGecko]

Oven should be at around 170F. You can turn the oven off before or after you put the soap in. Don’t ‘bake’ you soap. I covered mine with plastic wrap. Leave in the oven overnight. Sone folks also leave the oven light on...I don’t have one. One the soap is cool and feels like medium cheddar cheese, you can unmold and cut. I used a 33% Lye Concentration during the Spring/Summer and 35% during the Fall/Winter...I live ing the Pacific Northwest of the US and it can get pretty cold and damp and the higher Lye Concentration works best for me.

 

[KimW]

Such good questions, and I'm betting you're going to get a lot of different answers! Here are mine:
1. In the winter I heat the oven to lowest setting of 170F, put the soap in the oven, and leave the oven on for an hour. In the summer, I heat the oven to 170F, put the soap in and then turn the oven off. In both seasons I leave the soap in the oven overnight with the door closed, no light on.
2. I always cover my soap in plastic wrap. When I'm CPOPing, or otherwise forcing gel, I wrap the mold (top/bottom/sides) in a double towel, or a quilted cover.
3. I usually leave mine in the oven overnight. When the soap is cool and firm like - giving away some things here - government cheese/velveeta, I cut.
4. I don't know what's the best lye concentration. I'd go with what you're used to working with. I usually use 50% lye concentration unless I need a thinner and slower moving recipe, but I think most folks like a lower lye concentration.

 

[Katie68121]

Such good questions, and I'm betting you're going to get a lot of different answers! Here are mine:
1. In the winter I heat the oven to lowest setting of 170F, put the soap in the oven, and leave the oven on for an hour. In the summer, I heat the oven to 170F, put the soap in and then turn the oven off. In both seasons I leave the soap in the oven overnight with the door closed, no light on.
2. I always cover my soap in plastic wrap. When I'm CPOPing, or otherwise forcing gel, I wrap the mold (top/bottom/sides) in a double towel, or a quilted cover.
3. I usually leave mine in the oven overnight. When the soap is cool and firm like - giving away some things here - government cheese/velveeta, I cut.
4. I don't know what's the best lye concentration. I'd go with what you're used to working with. I usually use 50% lye concentration unless I need a thinner and slower moving recipe, but I think most folks like a lower lye concentration.

Thank you for sharing your methods! Another question I thought of...
what type of mold do you use? I have a wooden mold with silicone liner, is that ok?

 

[SoapDaddy70]

I always wonder about covering with plastic wrap. If you are using a standard 8 bar loaf mold and your batter comes close to the rim won't plastic wrap ruin whatever design you made on the top. I know not everyone makes a design on the top but every time I messed around with plastic wrap or freezer paper it always touched the top of the batter and got all messy. I finally jerryrigged a bunch of cut cardboard slats and made a little border that I place on top of my mold so it just covers the rim and is about an inch tall and then I cut a piece of cardboard that acts like a lid that I place on top of my little cardboard thingy.

 

[earlene]

Ovens vary, with different minimum heat settings. So my first suggestion is to invest in an oven thermometer. That way you will always know how hot it gets.

As for recommended heat, it also varies with your soap formula and your soaping temperatures as well as the ambient temperature inside your house while making soap.

For my oven, I turn it on to reach 150°F, turn it off when it has reached this temp & put the soap inside the oven with the door remaining closed. This works fine for most of my recipes.

Insulation: I do insulate some, but not all soaps that I CPOP. In some cases, I cover with plastic wrap, then a lightweight towel (shop rag type), and sometimes I will also invert a cardboard box over top of all that to keep the heat inside the soap. But it varies with the formula and the temperature of my home at the time.

I leave the soap in the oven for a few hours usually, but not always overnight. It really depends on when I put it inside the oven to start with. If I soap in the morning, it comes out in the afternoon.

I tend to soap at around [33% lye]*, sometimes higher, sometimes lower.

To answer SoapDaddy's question about plastic wrap, it depends on what type of design. If it a simple swirl with a smooth top, no. If it is raised embellishment, then yes, it would, especially if condensation drips back onto the soap top. In that case, I would not cover the soap going into the oven.

As far as what molds are oven safe, I have used cardboard box molds, wooden molds (with and without silicone liners), ED molds (silicone inside a stainless steel holder), HDPE molds and even silicone-only molds inside my oven with no ill effects. I do not own an acrylic mold, so cannot speak to those regarding oven safety.

*[33% lye] = 33% lye concentration, with the brackets around the 33% lye the symbol for the word concentration.

 

[GemstonePony]

Just popping in to add that using ingredients high in sugar such as honey, juice, or milk will heat the soap up more. High amounts of coconut oil will also heat the soap up, and some fragrances will as well. Also soap will gel at lower temperatures with more water, so you might need to make a judgement call on what temperature to pre-heat the oven to based on the sugar and water content in your recipe. Also, do you have a thermometer in your oven that gives the actual temperature? Ovens can vary from the set temperature by 25°f, so it's handy to know what temperature you're actually getting when you set the pre-heat to various settings.
I've had 100% CO soap in individual cavities go into gel just sitting on the counter in a 72°f house, so I would start lower temps and uncovered. If that doesn't work in a couple hours, pre-heat to 160° and turn off immediately, and cover.

 

[Quanta]

I do not own an acrylic mold, so cannot speak to those regarding oven safety.

I have used a warm oven before to soften pieces of acrylic so I could shape them. If anyone has an acrylic mold, DO NOT put it in a warm oven unless you want it to get soft.

 

[KimW]

Thank you for sharing your methods! Another question I thought of...
what type of mold do you use? I have a wooden mold with silicone liner, is that ok?

I use a wooden slab mold with a wooden lid that I line with cling wrap or "Press-N-Seal" wrap (I don't cover the soap with cling wrap since it has a wooden lid), homemade molds made with plastic sign board with no lining needed, and "new to me" HDPE molds which I lightly "grease" with mineral oil (as one would grease a baking pan). I've never used a silicone liner, but I do know there are lots of SMF posts about the Pros and Cons and the different brands.

I always wonder about covering with plastic wrap. If you are using a standard 8 bar loaf mold and your batter comes close to the rim won't plastic wrap ruin whatever design you made on the top. I know not everyone makes a design on the top but every time I messed around with plastic wrap or freezer paper it always touched the top of the batter and got all messy. I finally jerryrigged a bunch of cut cardboard slats and made a little border that I place on top of my mold so it just covers the rim and is about an inch tall and then I cut a piece of cardboard that acts like a lid that I place on top of my little cardboard thingy.

Agree! I don't do sculpted tops, but I do hate it when the plastic wrap dips down onto a loaf top and makes a wrinkly mess. I usually make my molds an inch or so higher than needed, but I'm going to use your fantastic idea for my HDPE molds!

 

[Todd Ziegler]

I can't add anymore on CPOP but an alternative to CPOP is using heating pads to wrap around your mold. I use 2 heating pads, one on top and one on bottom. Then I cover them in a few heavy towels.