The math is really not an issue. When you have your 50% solution and come to make a batch -
Amount of solution = lye amount x 2
Extra water to add = total water - lye amount.
The first one is because the solution is half water, half lye, so 100g of solution has 50g of lye.
The second is because, if you need 50g lye you added in 100g of solution, which includes 50g water. So if your recipe needs 200g water in total, you need to take 50g away as you already added it.
Master batching makes soaping a lot faster, I have to say. It has to limits (heat transfer doesn't work well, for example) but I can make a batch and be sat with a cup of tea before I know what happened.
I read through the forum link above and it said the lye solution lasts a very long time. Would this be a better way to store lye if you live in a humid climate? I live in the South and we have lots of humidity here in the summer and I am afraid my lye will not last long, especially since where it will be stored has no AC. So, I was thinking maybe when summer approaches, if I don't have allot of lye, I could master batch and not have to worry about it going bad? Is that a bad idea?
Lye will absorb water regardless of whether it's in solid form or in a solution. Store either one in a tightly closed container.
Songwind or KC (speaking from memory) goes a step further. He said he keeps his sealed containers of lye in a 5 gallon bucket with a desiccant (humidity absorber).
The top of the bucket is closed with a "gamma" lid that can be easily opened and closed, but you can also use the normal lid that comes with most 5 gallon buckets if you have a bucket lid wrench or don't mind removing the top with your hands.
That's what I'm working on to store my solid lye and lye solution (yes, I'm starting to masterbatch too!) Have the bucket with regular lid, now to find the gamma lid and desiccant.
Another thing is you can monitor your lye by weighing it. Susie explains she weighs her container of lye before she puts it away and then weighs it when she takes it back out to make more soap. Any additional weight the lye container picks up while it is in storage is an indication that the lye is absorbing water. The goal is to keep that to a minimum.
Hey, I knew we were practically kinda-sorta neighbors, but obviously I shouldn't be trying to rely just on my memory. Sorry, KC!
I'm already running on fumes and there's still another week of the holiday shopping season yet to go. :sick:
As time goes by I'm using more and more lye. I got through my previous Lye Guy "buy 5 get 1 free" purchase in a year. I took the plunge and bought two of these "specials" a few weeks ago, so I have even more reason to protect my investment. I'm looking forward to seeing how your bucket desiccator idea works for me this coming year. A single 5-gallon bucket will hold all of the containers of this order, by the way. The top containers need to lean a wee bit to fit, but they all go in!