master batching lye for large batches

[debsoap]

Hi I am totally new to this forum but have read so much information about this particular issue. They have been very helpful, however, most are making 2 or 3 lb bathes of soap while my batches are approximately 11lbs. I have been wanting to pre-mix my lye solution am wondering about the calculations for batches this large I have read about 30 threads!

If my recipe calls for 19.5 ounces of Lye and 44 ounces of Water. How would I calculate that ...for the 50% solution....all of my batches are the same %.

Numbers throw me sometimes and I have tried to do the math but with batches this large I wanted someone's opinion who has actually done the calculations before :razz:
Thanks!!!

I would like to make up enough for say...10- 11 lb bathces...can this be done?

 

[ZandarKoad]

If I understand your question correctly, you'd simply scale the recipe by a multiplicative factor. For example, I had a recipe that produced 2 lbs of soap. I thought that was a little whimpy, so I multiplied all ingredients x4 for my first batch to get 8 lbs. Then I did my black soap, and did x8 the recipe to get 16 lbs. It turned out great. I really don't like making batches smaller than 16 lbs. My preference would be 32 lb batches every time or greater. That size fits in a five gallon bucket really nice, and makes a fair amount of soap. I'm giving all the soap away, so I don't have to worry about marketing or selling. Yet.

 

[debsoap]

Well I already have the recipe for the 11 lb soap batch I am
Wanting to learn how to pre-mix a 50% Lye solution and have enough
Made ahead of time to be ready to make 10 batches or so

 

[ZandarKoad]

So just mix enough for a 110 lb batch. Take your recipe (19.5 ounces of lye and 44 ounces of water) and multiply times 10. 195 ounces of lye and 440 ounces of water. Though, I'm not so sure that's advisable. I would think it is much much easier (and safer) to store dry lye than a water solution... I'd only make what you are going to use that day. Perhaps you are going to make 10 batches in one day? I could see doing that... I couldn't see AFFORDING that, but I could see doing it.

 

[chicklet]

You mix up your master batch with half lye/half water in whatever amount you want depending on the size of your storage container. When you make soap, you measure out twice the amount of lye called for because you will be using half lye, half water. In your recipe you would measure out 19.5 oz times 2 or 39 oz. you then have all the lye you need for your recipe but not all the water. You measured out 19.5 oz of water so you subtract that from the total amout of water called for in your recipe. You need 44 oz total so 44 minus 19.5 equals 24.5 oz so you would add 24.5 more oz of water. Now you have 19.5 oz of lye and 44 oz of water in your lye mixing bucket.

 

[chicklet]

Now that I've read Zander's second reply I realize I may not have understood your question. Sorry.

 

[DWinMadison]

Hey, this begs a question. If you had a standard lye solution, could you premix it at 50% and store it until needed at room temp (labeled appropriately, of course) then dilute it with the other 50% warm water to bring it up to 110° f when it's time to soap?

 

[Marilyna]

Ha Ha! I know!

 

[debsoap]

Thank you for all the replies ZandarKoad I understand what you
Are saying , but like you mentioned it would be so much to
store at once , it would be less to store if I do it 50% using the method
that Chicklet described. I had read about doing it this way
But wasn't sure the math was right ��
Chicklet thank you! That was exactly the answer I needed! I was
Up half the night trying to figure it out!
DwinMadison, that was another question that I have. Would that work ?

I am so thankful to have found this forum! Thanks for all your answers!
ZandarKoad your reply answered a huge question I have had because I was told
That the calculations couldn't be done that way to multiply the recipe! I am
So glad to know that I CAN do it in this manner. For days of smaller
Batches made this would work great! I make 16 - 11 lb. batches
On days when I need to catch up.

Thanks again! Have a great day all!

 

[chicklet]

DW I'm not sure what you mean. Of course, I wasn't sure that I was sure what debsoap meant either and it turns out I WAS sure all along, but still . . . what do you mean "premix it at 50%" - do you mean half the lye and water called for in your recipe? Or half the water called for in your recipe? That's more than I can wrap my brain around. I haven't ever masterbatched lye, but I want to. I'm just trying to decide on a storage container. I haven't bought laundry detergent in a long time and I really would like to have some empty laundry detergent bottles to store master batches of lye/water. I just think that would be so simple with the spout and all. My plan when I either get some empty detergent bottles or come up with something else for storage is to fill them up with a 50/50 lye/water solution. Then when I go make soap I'll measure out twice as much from the master batch as what I need in the recipe, then subtract that from the total amount of water called for so I know how much extra water to put. It could be warm water . . . but it might be frozen milk or alove vera gel. If you make the same recipe every time, I guess you could master batch all the lye the recipe calls for mixed with half the water the recipe calls for so every time you go to make soap you know how much water you need (the missing half) - maybe that's what you were talking about? Whatever - but I'm going to try it. Last weekend I mixed up 4 batches of the oils needed for one batch of soap and this week it's been so easy to make soap at night!

 

[Trxflyer]

ZandarKoad & debsoap - What in the world do you poor such large quantities of soap into (molds)? A bunch of 10lb molds?, custom made molds?, homemade molds?. Do you actually cut that many bars at a time or are your molds already divided into bars? I'm trying to figure our how to go 10lbs+ but I can't figure out how to go with the molds / cutting. I'm trying to do giveaway soap and the small pound batches just isn't working well. Please solve this mystery!

 

[ZandarKoad]

I've got infinite, free cardboard boxes of all shapes and sizes from my day job. I line them with plastic wrap, and pour. The edge parts look funky with all kinds of lines and folds from the plastic wrap, but I don't care. It's hand made soap: those minor cosmetic defects are part of it's charm. I usually only pour about 1 and 1/2 inches deep, then cut length wise and width wise. It is a lot of cutting, but it goes fast. I can cut 100 bars in like 15 to 20 minutes.

Yeah, if you are giving this stuff away, you've got to go big right away. It's not fun giving away 5 bars. It IS fun giving away 500! Make sure your bars are nice and small and thin though. My bars are like 1.3 to 1.6 ounces. I think that's a little too big. I should have cut them thinner. I think 1.0 ounce is the perfect gift / sample size.

 

[debsoap]

TRXFLYER, I have custom molds that are made to hold my batches. They are wood and I line them with freezer paper. I had them made by someone I know and I have 20 of them. I am selling my soap and need to be able to do large amounts for my shows. I have been hand cutting for 13 years with 2 long blade knives I had made by the same person who made my molds but I just this year had someone else that I know make me wires cutters that are working just wonderfully!

 

[Trxflyer]

ZandarKoad - I think you've hit on a winning setup for the no thrills but fun way to give away soap I've never used cardboard boxes but I may give it a go as I have several from amazon stacked up in the spare room. Hate to see a perfectly good box just go to waste sitting there ;-)

debsoap - Sounds like a real pro setup. You are really fortunate to have friends with the skills & resources to make those things. I know it makes all the difference.

Thank you both for the feedback.

 

[CaraCara]

I have a question regarding water evaporation when master batching. I made a 50/50 water/lye solution and the contents got really hot as expected. I've made a few small HP test batches and measured, doubled the lye readings and added water accordingly with no zap and good results. Today I made a CP batch and the bars are sweating droplets of what I thought was water until I chewed on a fingernail without thinking and got zapped. This is a first (sweaty soap) so I'm wondering if maybe my solution is not 50/50 due to evaporation. Has anyone else experienced this?

 

[soapguy]

Well I already have the recipe for the 11 lb soap batch I am
Wanting to learn how to pre-mix a 50% Lye solution and have enough
Made ahead of time to be ready to make 10 batches or so

To make a 50% soln of naoh, you dissolve 50 grams of naoh in 100 grams of distilled water. For larger batches you just need to extrapolate. In your case multiply your calc by 10

 

[soapguy]

Has anyone else experienced this?

I have a batch that is lye heavy and still sweating after two years. I have been waiting to rebatch these someday with some other failed soap.

 

[DeeAnna]

"...To make a 50% soln of naoh, you dissolve 50 grams of naoh in 100 grams of distilled water...."

No! That is a 33% NaOH and water solution, not 50%. The correct math is this:

50 g NaOH / 150 g solution = 0.33 or 33%

A 50% solution of NaOH has equal weights of water and NaOH. To use your example, you would mix 50 g NaOH with 50 g water. The math:

50 g NaOH / 100 g solution = 0.50 or 50%

Edit: For all intents and purposes, you cannot make a lye solution more concentrated than about 52% NaOH. The excess NaOH will not dissolve. So for safety's sake, be sure you do not go higher than 50% NaOH in your master solution.

 

[soapguy]

"

Nope.
Percentage solutions can measured weight for weight. The figures I gave are close to 50%


Percent

One of the simplest forms of concentration is the percent. This simply means units per 100 units, or parts per 100 parts. The percent concentration can be used in three ways. It can be weight per weight, volume per volume or weight per volume basis.
When winemakers use °Brix hydrometer to measure sugars in grape juice they are essentially measuring grams of sugar per 100 grams of juice. A juice sample of 18 °Brix means 18 grams of sugar per 100 grams of juice or commonly referred as 18%. In describing the alcohol content of a wine, percent alcohol content is expressed in terms of a volume per volume basis. In many cases, including in a laboratory, a solution is made by dissolving a solid in a liquid, usually water. In such a case the concentration is expressed in a weight per volume basis.
http://www.extension.iastate.edu/wine/preparing-standard-sodium-hydroxide-solution
See also: http://www.scienceforums.net/topic/40019-making-a-highly-conc-naoh-solution/

 

[DeeAnna]

Yes, you are correct that NaOH solutions as used in soap making are calculated on a "weight for weight" basis, but you are incorrect in the weight used for the denominator for the calculation. The denominator is the weight of the solution, not the weight of the water alone.

Look at this phrase in the quote you provided: "...grams of sugar per 100 grams of juice..." It is not grams of sugar per grams of water. It is grams of sugar per total weight of the juice. The total weight of the juice is the combined weight of the sugar, water, and whatever else is in the juice.

The total weight of a lye solution is the weight of the water AND the weight of NaOH. Not just the weight of the water in the solution.

50 grams of NaOH dissolved in 100 grams of water makes 150 grams of solution. Written correctly and fully, this is a 33% w/w aqueous solution of NaOH -- one third of the solution is NaOH, in other words, with the balance being water.

50 grams of NaOH dissolved in 50 grams of water creates 100 grams of solution. This is a 50% w/w aqueous solution of NaOH. One half of the solution is NaOH.

I worked in a chem lab for years, I have taught chemistry, and I am a PhD engineer with years of chemical industrial experience. I absolutely know how to calculate solution concentrations correctly.