Yep. I usually premix my lye and use it the next day or when I get around to it. Just make sure it is covered so water does not evaporate. I actually just use cling wrap. Mind you it is placed on a high shelf so no one can get at it.mysoapopera said:If I mix lye and aloe and do not use it till a day or so is it safe with a lid on it in a glass jar, once the it has cooled down?? I was not sure about the lid?