Monday, June 25, 2012

Question: What happens if our recipe totals more than 100%?

In this post, Anonymous asks: Hey Susan, This probably is a very weird question, but I was wondering, just for curiosity's sake, what would happen if you made a change in a lotion recipe, say added extra of an ingredient in the oil phase but didnt reduce the percentage in the water phase (so the recipe didnt equal 100% anymore) what would happen? I've never done it, nor am I planning to, I was just curious if it was that important you reduce 1% if adding 1% somewhere else and what would the result be if it happened? Thanks!

The answer to this might shock you, so hold on...Nothing. Nothing would happen. You'd have a recipe that has a total of 103% or a 105%, but it wouldn't be a ruined recipe. I admit that I have quite a few recipes that total more than 100% for various reasons. Perhaps I wanted to add 2% fragrance oil to something like a sugar scrub or I realized I wanted to add 3% cationic polymer in my conditioner, I can just add it in and accept that my recipe isn't exactly 100%.

There are very good reasons for making our recipe total 100%, the main one being that it's easier to ensure a product has the right amount of each ingredient, and I encourage you to strive to have your recipes total 100%.

Having said this, I don't think it's a good idea to increase your oil phase with reckless abandonment. If you increase an oil - for instance, going from 5% rice bran oil to 9% rice bran oil - you need to increase your emulsifier to ensure the lotion will emulsify properly. If you're using Polawax, you'd want to increase it by 1%, so now you'd have an increase in 5% in the oil phase. Now you have a lotion that works out to 105%. The lotion will work at 105%, as long as you increase the emulsifier!

Thanks for the great question, Anonymous!

Related posts:
Calculating percentages in products
Making larger batches of products - how to double or triple that recipe! 
Why we weigh our ingredients.
How to convert recipes from percentages to weight
Using Polawax and that 25% rule


melian1 said...

my recipes as made are often a little different than the formula i started with. most often due to over-pour, lol. but i ALWAYS keep strictly accurate notes of how many grams of everything i actually put in. it does make a difference in the finished lotion.

one time i nearly dropped a bottle of cyclo while i was pouring and ended up with an extra 4 or 5% (over the 1% i'd planned). it turned out to be the most wonderful lotion so i upped the formula amount to reflect that (making the adjustments in the formula so it once again was 100%).

that also taught me to pour into one vessel, and then add that to the main batch instead of pouring additional ingredients into the main batch as i go, lol.

Jessica said...

If you make a recipe that totals over 100% -- the total is still 100% (you can't put more than 100% in something), but you have less than you expected of your ingredients. So if you write a recipe with 5% oils and it totals to 105% instead of 100%, you actually have 4.8% oils. So, not usually a big deal if you're talking about 3 or 5% over (like Susan said). But it can make a difference in terms of oil/water emulsions (like she said as well). My point is more of a technical one: you can never REALLY have more than 100% of the total. The total is your total volume - 150 grams or however much you make. You can always re-calculate your recipe to see how much your actual percentages are if you find yourself over...just divide each ingredient's quantity by the total volume. Then you should be able to easily see whether your ratios are adequate. Right Susan?

Anonymous said...

Thank you! Thank you! Thank you! I have had so many arguements with my sister over this very subject. Because sometimes I go over that 100% just a tad. ~ Best regards, Renee

Mychelle said...

I do this occasionally as well, with anhydrous products in particular. I am more cautious with lotions only because I calculated my preservative amount to cover 100% of my total and I'm careful to stick to that - most of the time. As to Jessica's clarification, I'm not sure that's accurate? If I'm making 8 ounces of shampoo and I toss in 3% extra glycerin on top of a formula that adds up to 100% then I now have 103% of 8 ounces. I didn't decrease my other ingredients, I just have more in there. That's how I see the math anyways.

Susan Barclay-Nichols said...

I think it's probably easier to define the recipe - for the moment - as having 100 somethings (grams, ounces, not percent), so we can exceed 100. If you go over that 100 mark, then you can recalculate the recipe to get it back to 100, but if it's over by a tiny bit, I don't stress too much about it, as long as the ratios are right. If I get to 103, I'm not that worried, but 110 is too far.

By definition, we can't have more than 100% of something, and I would encourage you to recalculate if you are going over by a huge amount because it could mess up your product!

For anhydrous products, I wouldn't worry too much about it. For products that require emulsifiers or preservatives, I would make sure that both are in balance with the product!

Kirk said...

Mychelle, Jessica is correct, as are you. You are both talking about different aspects, though.

Take your your 8 ounce recipe that you alter to add 3% glycerin to. You now have a recipe that makes 8.24 ounces of product. Adding 3% glycerin, though, changes the ratios of everything and means that the recipe, written as percentages, will have a smaller percentage of everything else. That is what Jessica is trying to point out.

Altering a recipe on the fly to go over (or under) 100% isn't necessarily harmful, but it changes the ratios of all of the ingredients. If it turns out to be a change that one wants to be able to repeat, the smart thing to do is to recalculate new percentages of everything so that the recipe once again adds to 100%.

Anonymous said...

LOL Well I'm glad some of you found it helpful. I felt really stupid asking it, but I guess I wasn't the only one wondering about it! :)

(Since I dont feel so silly anymore)

Mychelle said...

Ah, well said.

la tía maruja said...

It wasn't a stupid question! I think it's the kind of question everybody thinks about and nobody asks... Thanks for sharing! Your blog is awesome! Kisses from Spain!

catherine said...

hi everyone. i hope it won't seem presumptuous to provide this info...i am really hoping it will help! :)

this issue has been important to me because at times i did go over the recipe percentages, *liked* the "new" lotion, then wanted to make sure I could repeat the new lotion.'s how i calculate new percentages:

let's say you have a basic recipe:

70% water
15% oil
5% butter
3% thickener
6% emulsifier
1% preservative

If you were making 100 grams of lotion with this basic recipe:

70 g water (70% of 100 grams is 70 grams, and so on...)
15 g oil
5 g butter
3 g thickener
6 g emulsifier
1 g preservative
100 g total

But you accidentally add too much oil and butter:

70 g water
16 g oil
6 g butter
3 g thickener
6 g emulsifier
1 g preservative
102 g total

notice you don't have 100 g anymore, you have 102 grams. So the original percentages no longer apply. If you like the new "accidental" recipe and want to repeat it you would have to calculate the new percentages. The new %s would be:

grams of ingredient/grams of total recipe

So the new recipe would be:

70/102 = 68.6% water
16/102 = 15.7% oil
6/102 = 5.9% oil
3/102 = 2.9% thickener
6/102 = 5.9% emulsifier
1/102 = 1% preservative

hope this helps! :)

Heather said...

Hi Susan!

I don´t know anything about chemistry and I´m trying to learn as I go hehe... So this might seem like a stupid question but, If nothing happens if you go over 100%, does the same principle apply for the opposite? I wanted to try and modify one of your formulas (emulsified sugar scrub) by decreasing the oil percentage and leaving everything else the same. I love the original formula! But I would like to make it less greasy and hopefully, keep it from separating (I´ve asked you about this in a different post hehe)

Your formuala:
10% e-wax
10% cetyl alcohol
20% cocoa butter
56% oil
1% vitamin E
1% preservative
2% fragrance oil

What would happen if I just decrease the oils to 46% and leave everything else the same?

I tried decreasing the oils by 10% and increasing the cetyl alcohol by 10% as you suggested in one of your posts. Although it doesn´t separate and it´s pretty stiff, I think it´s too hard to scoop out of the jar and I´m afraid it might get too hard if used in cooler weather.

Thanks again!


Susan Barclay-Nichols said...

Hi Heather! When you go under 100%, you're actually using more of each ingredient than you think by percentage. So let's say you have 20% oils in a recipe and 10% emulsifier. If you go down to 10% oils, you've changed the ratio of the oils to emulsifier from 2:1 to 1:1, which is a big difference. As well, if your percentage is less than 100%, you might be off in how much preservative or fragrance amounts. In the grand scheme of things, in this recipe, it won't make a big difference.

So go to 10% if you want. Curious though, why reduce the oils? What's the reason?

Heather said...

Hi Susan!
Thanks for your reply. I'be just been trying to make it feel less greasy and keep it from
Separating so I thought maybe reducing the oils might help. I'll let you know if it did or if it turned out to be an epic fail lol!



Heather said...

I forgot to add to my previous comment...

So, if I decrease the oils, should I just recalculate the recipe in percentages? Just like I would if I would go over 100% ...?


Heather :)

Susan Barclay-Nichols said...

Hi Heather! Yes! Recalculate it!