Master Batching Lye Water- Cool Down

[Cellador]

Hi all! I just finished making my first Masterbatch of lye solution, and I had a quick question I can't find an answer for. Do you leave the container lid on or off while the solution is cooling? Or does it even matter?
EDITED: typo

 

[bshultz33]

I know this isn't an answer to your question ( I'm new to this ) but how do you calculate how much solution you need, how long does it last and can you use it at room temperature?

 

[penelopejane]

Hi all! I just finished making my first Masterbatch of lye solution, and I had a quick question I can't find an answer for. Do you leave the container lid on or off while the solution is cooling? Or does it even matter?
EDITED: typo

I leave the lid off until it’s luke warm.

 

[Cellador]

I know this isn't an answer to your question ( I'm new to this ) but how do you calculate how much solution you need, how long does it last and can you use it at room temperature?

For master batching? I made a 50% lye 50% water solution and will dilute the solution further once I'm ready to use it. I just took the amount of lye I normally need for 4 to 5 batches and mixed it with equal parts water.
From what I understand, the solution will warm a bit when I add the additional water.
I'm not sure how long it will last, but I will probably use mine within a month or so.

 

[Lin19687]

I also do not MB, but if you use the same solution for all your batches, wouldn't it be easier to just make up a big batch? That way you don't have to add water to it? Then it would be room temp .

 

[Cellador]

I also do not MB, but if you use the same solution for all your batches, wouldn't it be easier to just make up a big batch? That way you don't have to add water to it? Then it would be room temp .

Yes, but I switch my lye to water ratio depending on the type of soap I'm making. And, the math will be easier (I think! Lol). From what I understand, it only heats to about 105 degrees F, so it doesn't heat too much.

 

[shunt2011]

I too MB my lye in a 50/50 solution. I use milks as the remainder of my liquids. I leave the lid off with just a paper towel over the top until it's just warm. Then cap it. I add the liquid difference to my oils not my lye mixture.

 

[amd]

I put the lid on mine, with the pour spout popped open so that any heat or evaporation can escape. I'm too clumsy to leave it open all the way. I don't have kids or cats in my soap area, but I still worry about it getting knocked over (ghosts).

 

[DeeAnna]

...Do you leave the container lid on or off while the solution is cooling?...

I masterbatch my lye. I usually cover the opening of the container loosely until the lye solution cools to keep fresh air (less carbon dioxide -> fewer floaters), dust, and bugs out. A cover also reduces evaporation of water while the solution is really hot.

It's very important to not screw a lid on tight, however -- you don't want pressure to build up in the container. Either just set the cap on top or cover the opening with a piece of waxed paper. Or something similar.

...if you use the same solution for all your batches, wouldn't it be easier to just make up a big batch? That way you don't have to add water to it?...

You certainly could. There's nothing wrong with that idea if you always use one set lye concentration and make your masterbatch solution at that concentration. There are some of downsides to using a lower concentration masterbatch that may or may not be an issue for you --

Lower concentration means you either have more volume of liquid to store, or you get fewer batches of soap from a given volume of masterbatched lye.
Can't make milk, beer, and similar soaps soaps using the "split method" where you make a 50% lye solution with water and use the other liquid to make up the rest of the water.
May not be able to adjust the lye concentration to suit the type of soap being made. For example I use a higher lye concentration for castile type (high oleic) soaps, lower concentration for hot process or high coconut oil (high lauric-myristic) soaps.​

 

[jcandleattic]

I make 24lb 50/50 masterbatch which heats up quite a bit while making. Once all the lye has dissolved, I will put the lid on the bucket loosely until it's cool to the touch on the outside of the bucket, then I will weigh it out, and any evaporation that has occurred I will replace then put the lid on tightly at that point, until I am ready to transfer the solution to my lye container.

When I want to make a milk or beer soap, I will either add the remaining liquid I need for my recipe to the 50/50 solution, or I will just redo the lye solution with 100% milk or beer.

 

[IrishLass]

I make a 50/50 master-batch solution in a large Rubbermaid pitcher and put its matching lid on during cool down. I adjust the lid just a little so that there's a small air gap. When all is cool, I weigh and replenish any water that was lost to evaporation before transferring to an HDPE container with a tight-fitting lid.


IrishLass

 

[earlene]

Hi all! I just finished making my first Masterbatch of lye solution, and I had a quick question I can't find an answer for. Do you leave the container lid on or off while the solution is cooling? Or does it even matter?
EDITED: typo

I use a pitcher that has a lid with 3 closure options, much like this one (link) for the mixing. I keep the lid on while cooling. With the lid on, evaporate rises to the top of the pitcher, gets caught on the inside of the lid and will drip back down. There is less water waste with this method, IMO. At first I thought I'd turn the lid one way or another to allow for heat escape, but that's not at all necessary. I always put the pitcher in a round plastic tub to be sure it won't get knocked over, and then in the sink. If I want it to cool faster, I fill the tub with some cold water to facilitate a faster cooling.

After cool, I pour the mb into ED lye bottles, tightly close the 'child-proof' lids and put dates on masking tape on each bottle. These full bottles of mb lye solution are then kept in the same tub I mentioned before and the whole kit & kaboodle lives in a spare shower in my bathroom down the hall between my kitchen & laundry room.

Also, I always weigh before and after to keep track of any water loss in my mb solution, and find there is very little lost to evaporation with this method.