Making lye water in advance.

I read some where that you can make lye solution up ahead of time and warm it up when ready to make soap. To me that sounds easier than trying to cool the lye solution and oils at the same time. My question is, is there a limit as to how far in advance you can make up the lye solution? Once the lye and water are mixed, does it have a shelf life?

Thanks
Willy

R u talking about masterbatching your lye??
There's a ton of threads about it here in the search engine, though I don't do it myself.
I do however make my lye in single containers ahead of time. Either the day or week before. I put lids on the containers once the heat has gone.
I definitely don't reheat it though. I melt all my solid oils, put in the room temp oils, add the lye solution, then the soaping temp is pretty much spot on for me.

I make mine in advance too and I agree with not reheating it. I also mix mine 50/50 and adjust my lye concentration accordingly when it's time to make soap by adding extra liquid. As nattynoo said... search the threads for master batching and you should find plenty of discussions on the topic.

As for shelf life... I don't always get to make soap as much as I'd like and have used lye solution as old as 6 months with no issues. I keep it in a well marked HDPE laundry detergent bottle and just give it a really good shake before using.

xyxoxy said:

As for shelf life... I don't always get to make soap as much as I'd like and have used lye solution as old as 6 months with no issues. I keep it in a well marked HDPE laundry detergent bottle and just give it a really good shake before using.

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Same here. I'm currently using up an 8 month old masterbatch of 50/50 solution and it still works perfectly fine. No negative issues with my soaps or anything like that.

IrishLass

I thought it was necessary to have the temperature of the lye solution within a few degrees of the oil. Was I misinformed? If that is not the case, it would make things a lot easier.

I've never done this before. How do you calculate the amount of lye solution into total oil?

Wilster98 said:

I thought it was necessary to have the temperature of the lye solution within a few degrees of the oil. Was I misinformed? If that is not the case, it would make things a lot easier.

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It all depends on your formula and what oils/fats you are using. For instance, I use a large % of hard fats in some of my formulas and so I like to keep the temp of my lye solution and melted fats in those particular formulas close enough so that I don't end up with pseudo-trace. In those batches I heat my oils/fats to 120 degreesF, and I warm my prebatched lye solution up to about 100 degreesF (I warm it up in my sink in in a hot water bath while my hard fats are melting). This balancing act works for me in keeping my melted fats from reverting back to their solid state when the cooler lye solution hits them (which kept happening when I soaped them cooler). In my 100% Castile formula, though, it doesn't matter how close or far apart the temps are at all.


IrishLass

HomeBrew said:

I've never done this before. How do you calculate the amount of lye solution into total oil?

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It's very easy if you make a 50% masterbatch solution (50% water/50% lye). First, run your recipe through a good lye calculator as you would normally do, and then use this simple equation:

Total recipe amount of lye X 2 = how much of the 50% lye solution to weigh out for your batch.

Total recipe amount of liquid – the total recipe amount of lye = how much more liquid to add to your batch.

Because the masterbatch is a 50% solution, the above equation will work for each and every recipe regardless of the lye solution % you type into the lye calculator.

IrishLass

That formula works perfectly IL.

Because I almost always soap with a 33% solution (2 parts liquid to 1 part lye) and because I stink at math, it can even get a bit easier.

If you think of your 50/50 solution as your lye and then swap the numbers from soapcalc (Lye amount-> Liquid amount and vice versa) then you will have a 33% solution.

So if at a 33% solution your recipe says you need 50 grams of lye and 100 grams of liquid, then what you really need is 100 grams of your 50/50 solution and 50 grams of additional liquid.

I hope that's not too confusing.

I've seen a lot of people using HDPE containers (ie. old laundry detergent bottles) to store cooled lye water in, but what do y'all mix your lye and water in? I've heard glass is a no-no because the lye can etch the glass which could cause unexpected glass explosions. I've also heard that HDPE can't stand up to the high temperatures the lye water gets up to when you mix them together. Just curious what everyone uses.

Thanks!

I will *only* master batch my lye now. It has saved me an unbelievable amount of time when it comes to making soap, and while it isn't difficult, I do recommend waiting until you're a little more comfortable with making it the usual way (if you're new to soapmaking). My entire reason for starting to master batch my lye was to help eliminate soda ash. I live in a fairly arid climate, and found that regardless of what I did, I ended up with atrocious soda ash on my soaps. I read somewhere that water discounting could help with that, and researching *that* led me to master batching my lye. LOL I now use a 33% solution, and have had either very little or no soda ash.

I make 30 oz master batches at a time, and I store the COOLED lye pre-mix in these containers: 32 oz Utility Jugs. I've had absolutely no issue storing it in these. I do NOT mix it in these; I have plastic HDPE buckets that I mix in & allow to cool to room temp (without issue), then funnel-transfer to these. I make soap about every other week, and have had zero issues with the longevity of the lye solution. DO make sure to shake it up before you measure out what you need. (Well, gently shake it up. I pretty much just tilt the jug back and forth a few times.)

As far as heating it up goes, it's going to do that automatically when you add the required amount of extra water to it, per the calculations, so I heat my oils first, and when they're down to about 130 degrees, I go ahead and add the extra water to my lye pre-mix solution to bring the temperatures in line. I soap at ~110 degrees.

Hope this helps!

-Maevyn

Seriously, what is happening this evening with necroing old posts. It's not even like this is the most recent or best thread on master batching

This would also be appropriate, Craig...

Wow. Incredibly rude.

Please remove my account. I don't wish to be a part of a place that I thought would be helpful, but is actually something where such hatefulness occurs. People replying to an old thread is no excuse for such behavior, and for the record, I only replied because the previous post was so recent. Your responses were unwarranted & unnecessary.

Maevyn said:

Wow. Incredibly rude.

Please remove my account. I don't wish to be a part of a place that I thought would be helpful, but is actually something where such hatefulness occurs. People replying to an old thread is no excuse for such behavior, and for the record, I only replied because the previous post was so recent. Your responses were unwarranted & unnecessary.

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Such hatefulness? Really? I am sorry but I think that is more than a little OTT. But it is your choice.

The forum guidelines on necroing threads is in part because of what happened in your case - people don't notice it is old and cover roads already often travelled and in many cases referencing methods long since abandoned.

But as I said, it's your choice if you want to miss out on the helpfulness because you take some lightheartedness as hatefulness.

I just don't understand why commenting on an old thread is an issue. People get mad when you make a thread on a topic already covered, get mad when you reply to an old thread... the list goes on. It's pretty sad... everyone is here because they love making soap, are just starting out, etc. Why does everyone feel the need to be rude?

For what it's worth, I actually enjoyed reading this thread and haven't seen it before.

I was just joking around and I'm sure Craig was too! I've just seen a lot of necroposting today, thought it'd be alright to have a laugh about it. No offense intended.

Thanks for the reply Maevyn, but I'm asking about what you MIX your lye water in. I'm not too concerned about storage, just curious what everyone uses for mixing.

HappyHenrySoap said:

Thanks for the reply Maevyn, but I'm asking about what you MIX your lye water in. I'm not too concerned about storage, just curious what everyone uses for mixing.

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I mix in a SS bowl. I always use SS just for piece of mind.

I mix my lye and water in a stainless steel bain marie. But only because I have it. Otherwise, I would just mix it in my soaping bowls. I store my masterbatched lye water in the bottles I get my dry NaOH and KOH from ED in. I pour it in there once it cools down.

I normally suggest people start a new thread, but I honestly did not see that this was necro'd, and I was answering a newbie to the forum.

However, we don't get made when people ask things that are already covered. 99% of what is discussed has already been covered. We may kindly refer you to a thread that is AWESOME so you get the whole story with lots of opinions, but we don't get mad.

We don't even get mad when you necro a thread. We may comment that it is necro'd and suggest a new thread. We may even have a joke about necro'd threads. Not about YOU, just necro'd threads in general.

However, if folks are going to get their feelings hurt about this, they may want to get thicker skin if they want to stay on this forum.