Soap Newbie with Questions About Water

[katiem]

I have 2 questions regarding water in soap making:

1. We just moved to an area with really hard water. Where we were at before, we had slightly hard water, and I made 2 batches of soap, both using just filtered tap water, and they turned out fine. Now that our water is really hard, I'm wondering if the soap will still turn out ok if I use filtered water, if I should boil it first, let it sit out overnight, or if it is really necessary to use distilled water. Will using hard water cause the lye to not fully react, making the soap harmful?

2. When measuring the water for the lye/water solution, is it by weight or by volume? I've never seen a definitive answer on this question.

 

[Suisan2]

1. used distilled water. The calcium in the hard water can interfere with the lye reaction.

2. Always by weight. (However, as it happens, the density of water is defined as being 1 -- therefore its volume and weight are the same: 1 ml = 1 cc = 1 g. So when you are weighing water, it doesn't really matter. But when you measure oils, volume is wrong -- you need to use weight).

 

[IrishLass]

Welcome Katiem!

You can use tap water to soap with (many do), but it has been known to lead to some problems, depending on the concentration level of the various metals in it (from what I've read from others). If the concentration is really high, I'd use distilled.

In soapmaking, it's best to weigh everything. Even though water is a unique liquid with the property where it's amount in weight is the same as it's amount in fluid ounces, it is still best to weigh it seeing as how we don't always 'eyeball' fluid measurements in the measuring cup as accurately or consistantly as we'd like. At least with a scale, you'll know your measurements will be consistant every time (as well as the outcome of your finished batches).


IrishLass

 

[katiem]

Thank you for your responses. I ended up making a small batch with filtered tap water to see how it would turn out. I use the crock pot hot process method and it so far seems to be ok, it passed the zap test.

 

[IrishLass]

Good job!

IrishLass

 

[Jezzy]

I use to live in southern Germany where the water was incredibally hard. I still used it and never had a problem...