Soapcalc question

[happymom]

Hi everyone, I HP'd Lindy's famous shampoo bar this weekend - this is batch # 13 of soap for me.

http://www.soapmakingforum.com/f11/shampoo-bar-thanks-lindy-30946/

I started out measuring out my oils separately (in my first few batches), but I was concerned because you leave a little bit of oil behind in each container, so lately I have been weighing them all in my crock pot insert. This has been working fine until... I poured the OO too fast for my scale to keep up and ended up adding 1.5 oz too much olive oil to the other oils.

So I thought I'll just go back and adjust the recipe in SoapCalc. Since it is a shampoo bar what I wanted to do is keep the ratios of the other oils to my new amount of OO.

I could not figure out how to do it in Soapcalc - I tried all kinds of different things, but it seems like you have to start with the overall weight of the oils. Which I didn't know - I could add 1.5 of the OO to the 16 oz i started with but that changed all the other oils of course. I could have sat down with a calculator and figured out, if my OO went up by 1.5 oz, what would be the increase in the other oils, and added together what would be the weight of the total oil, but that sort of defeats the purpose of a soap calculator. In the end I just added the extra OO and calculated for the adjusted lye but there must be a better way to do it.

So seasoned soapers - how would you have handled this?

Thank you so much!

 

[Mark the Box Guy]

This morning I was working through my first batch of Crockpot soap from a recipe that looked straightforward and basic, but as I measured my oil I simply plugged the small overages and underages into SoapCalc and recomputed the lye water. My sense is that while an extra gram here or there won't change the soap's characteristic's in any significant way, getting the lye wrong would certainly do so. So my thinking was: get the recipe measurement weights as close as possible, and plug the differences into SoapCalc as I go along.

As far as I can tell, the soap came out strong and true.

 

[VanessaP]

I could not figure out how to do it in Soapcalc - I tried all kinds of different things, but it seems like you have to start with the overall weight of the oils. Which I didn't know - I could add 1.5 of the OO to the 16 oz i started with but that changed all the other oils of course. I could have sat down with a calculator and figured out, if my OO went up by 1.5 oz, what would be the increase in the other oils, and added together what would be the weight of the total oil, but that sort of defeats the purpose of a soap calculator. In the end I just added the extra OO and calculated for the adjusted lye but there must be a better way to do it.

What you do is put in your original formula and hit Calculate. Then, you want to click on the button on the side of the formula itself to edit the actual amount of oil. Then hit Calculate again and it will adjust the % for you and then you can view again to see the lye changes. The pic below is where I mean for you to switch. The green boxes are the boxes you can edit, so you have to switch to the oz (or gram, whichever measurement you're working in) in order to edit them.

 

[happymom]

Thank you so much for your replies. VanessaP, I see what you are saying... but my problem is this: if I overpoured an oil in a regular soap recipe I could just add it and recalculate - got that. But since this recipe was a shampoo bar, I wanted to keep the overall ratios the same. So I started with 16 oz of oils, the ratios in that recipe are Avocado Oil: 30% Castor Oil: 10% Olive Oil: 40% Shea Butter: 10% Soybean Oil: 10%.

So I overpoured the OO - now my total weight is 17.5, and OO is more than 40%. If I was making reg soap (not a shampoo bar), I would recalc for the adjust lye and it would be fine. But I wanted to add enough to the others, bringing up the total weight, so that the percentages lined up and OO was again 40%. This is what I couldn't figure out.

I added the extra 1.5 oz of OO to the total oil (so now it's 17.5). But I couldn't simply readjust the values in the percentage column because for it to add up to 100% I would have to know the correct total weight of all the oils - Soapcalc wouldn't let me leave it blank and then figure it out for me. So I would have to manually calculate ok I need to add maybe half an ounce of soybean, half an ounce of avocado (just making up these values) etc and then add the extra oz from the other 4 oils to the total weight in order for the percentages to then readjust to Avocado Oil: 30% Castor Oil: 10% Olive Oil: 40% Shea Butter: 10% Soybean Oil: 10%

does this make sense?

 

[VanessaP]

Ahhh, in that case, I would just play with the total amount of oils. Such as the original formula, 40% olive oil is 6.4oz. You added an extra 1.5oz, so you're looking for a total amount of oils where the olive oil is close to 7.9 oz.

19.75oz total oils = 7.9 oz olive oil. Just keep playing with the total oil weight on SoapCalc.

 

[DeeAnna]

"...So I overpoured the OO - now my total weight is 17.5, and OO is more than 40%.... I wanted to add enough to the others, bringing up the total weight, so that the percentages lined up and OO was again 40%.

Okay, so you have the dreaded "ratio problem" so hated and feared by my freshman algebra students. :smile:

You overpoured by 1.5 ounces and you want to know how much more of the other oils to add to keep the % of each oil the same as in your original recipe. First thing -- by how much did you over-pour the OO?

The answer is this: 1.5 divided by 16 = 0.09375.

In other words, you added 9.375% more OO than your old recipe called for. You need to multiply each oil weight in your OLD recipe by 0.09375 and add that extra to the old weight. These new numbers are the oil weights for your NEW recipe. Here's what I came up with when I did that:

Oil % OLD, oz NEW, oz
Avocado 30% 16.00 17.50
Castor 10% 5.33 5.83
OO 40% 21.33 23.33
Shea 10% 5.33 5.83
Soybean 10% 5.33 5.83
Total 100% 53.33 58.33