Help confirm I've got this right? Lavender oil amount...

[Tara_H]

Hi all, so it's been a while since I posted about my first ever soap (a liquid one I was having trouble with) and I only got around to a second one last month.

I decided to keep it super simple and went with the following (cold process):

• 500g beef tallow
• 325g olive oil
• 175g coconut oil.

So far so good and it all worked as expected and made a whole bunch of cream coloured bars which are mostly exactly what I wanted but tend to have bubbles (because of my poor wand technique) and a slightly beefy smell due presumably to the superfat tallow.

I've been wanting to make some lavender soap for a while and today I figured, why not rebatch some of the beefy soap and add lavender essential oil? I don't care at all about rustic looking, if anything that's a bonus and it's intended for personal/family use anyway. Following Oven Rebatch (CP), I've grated the uglier bars and added a little liquid and they're in the oven as I type.

Then (yes, wrong order to do things) I went to check exactly how much lavender essential oil I should be using. These are the calculations I made:

grated soap - 782.5g
kept soap - 453.5g

total soap - 1236g -> 63% rebatched

Given that I used 1000g of oil in the original recipe, that means there is/was 633g oil in rebatch. At 3% of oils that gives 19g EO needed, which seems like a lot?? Also the bottle I have is only 10ml...

I know it's very last minute to be asking but if any kind soul happens to come across this and can give me a sense check on the numbers that would be fantastic. At the worst I guess I'll end up with a potentially very mildly scented (and maybe still slightly beefy) soap.

Thanks in advance, will try to add pics also.

Bars I kept:


Grated soap for melting:


Mould prepared for after (washed & dried milk cartons being held in an adjustable bread tin):


Ok, I went ahead, so fingers crossed it's not ridiculously too much oil (which I doubt from what I've found).

I didn't feel like the soap was really melting properly in the oven, it seemed to be sort of drying out on top(?) so I put it in a double boiler setup after the hour was up and continued from there. It successfully turned to a mashed potato texture, so I added in the full 10ml of lavender essential oil that I had. I also mixed some candle wax colour with about 1/2 tbsp coconut oil to see if I could make it slightly purple, but that didn't seem to do much and I didn't want to put more in at that point.

Spooned it into the mould and pushed it into the edges/corners as best I could, then sprinkled on a generous amount of dried lavender which we had harvested from the garden. From what I understand it's likely to go somewhat brown, but given that the colouring hadn't really worked, I wanted some easy way of telling the bars apart, and again it's only for our use.

So hopefully this will result in something reasonably usable - the kitchen at least smells gorgeous at the moment! Pics below; I'd still love any feedback on what I've done so far so that if I've made any massive mistakes I won't be surprised by the outcome somewhere down the road...

After coming out of the oven - still a lot not melted at this stage:


In the mould:


Topped with lavender:

 

[cmzaha]

I see a couple of issues here. One is the lavender buds on the top will usually start turning black over time and look like mouse poop, plus many do not like botanicals going down their drains. The second problem is candle colorants are Not body-safe and it is very hard to color rebatch.

If you had just added more liquid to your oven rebatch it would be melted down just fine. There is no definite amount of liquid to use when rebatching since more than one factor controls the meltdown, one being how old and dry the soap is. Some folks like to pour liquid over the shreds the night before and left it overnight to absorb the liquid.

 

[DeeAnna]

It looks to me like your scent calculations are correct. Lavender EO is a fairly safe essential oil for use on the skin, so your goal of a 3% dosage is a skin-safe amount for lavender.

Bear in mind that 10 mL of lavender EO don't necessarily weigh 10 grams. I haven't looked up the specific gravity of this EO, but it's my guess you added something less than 10 grams, so the dosage is lower -- somewhere between 1% and 1.5% by weight, based on the weight of fats. That's going to be a very light scent after the soap is fully cured.

The lavender buds are going to turn into dark brown bits that look kinda (well, okay, a lot) like mouse poo.

I understand about the romantic look of flower buds and petals, rolled oats, and other things people put on or in soap. These embellishments can make a mess in the tub or shower ... or the user has to cut or pick them off ... and in the right (wrong?) circumstances, this stuff can even get moldy. Maybe next time put just a light sprinkle of buds down the center?

 

[Tara_H]

Thanks for the feedback!

The oil was the main thing I was concerned about since I'm more used to the kind of applications that call for a couple of drops rather than a whole bottle. I figured the 10ml would be less than 10g since it's obviously going to be less dense than water at least, but unfortunately that was all I actually had. Good to know that my calculations at least were right; next time I'll be more prepared and calculate it all ahead of time.

I hear you both on the lavender buds; again, this is mostly (probably exclusively) going to be used by me and my husband so I'm not worried about them going brown, but I'll keep a careful eye out for signs of going mouldy! I cut it into bars and as I expected the majority of it fell off anyway (since the batter was so thick, they didn't really sink/stick in any meaningful way).

I was surprised about the colouring not being body safe since I did a bunch of reading on this forum which ultimately led me to believe that it would be ok. Also the candle kit the colouring came from is intended for kids; although I guess that doesn't mean a whole lot if you're using the contents for a different purpose. In any case it was a very tiny amount I used, so after being split between bars the amount in contact with skin in any given use should be minuscule. I guess I'll keep it for handwashing though, rather than use in baths/showers.

Pics below, probably not to everyone's taste but I'm super happy with how they look right now at least: