Temperature of lye water

[TheMadScientist]

I made a very small batch of soap, my first. 10oz total. Didn't have to use very much lye and water but is it normal that it only reached 120 degrees? I was expecting it to get hotter. Is it because it was such a small amount?

 

[seven]

yes, a smaller batch will generate less heat.

 

[TheMadScientist]

Ok, thank you!

 

[CrisMaz]

If you're trying out recipes, messing around with oil combos and ratios, or testing out colorants and additives, how useful is a really small batch? I was thinking that smaller batches would be more cost effective if some recipes don't work out at all, but will the process/end result actually be indicative of the *real* reactions between all the ingredients since the temperature generated is lower?

Maybe if gel is forced the end result would be a little closer to what would happen in a much larger batch?

 

[Dorymae]

It will be basicly the same as long as the proportions are the same. This is why you make small batches in grams because you need more accuracy to keep the right proportions. Gel doesn't really matter that much when testing. You know gelled will be a little brighter but not drastically and really what you are looking for is whether it morphes out on you.

 

[eucalypta]

If you're trying out recipes, messing around with oil combos and ratios, or testing out colourants and additives, how useful is a really small batch? I was thinking that smaller batches would be more cost effective if some recipes don't work out at all, but will the process/end result actually be indicative of the *real* reactions between all the ingredients since the temperature generated is lower?

Maybe if gel is forced the end result would be a little closer to what would happen in a much larger batch?

I think making a smallish batch gives you an indication of what's ahead if you'd make a larger batch, technically speaking.
(Like is a fragrance oil going to seize on you.)

Colours (pigments/mica's) don't change behaviour in a large batch. Either they're affected by the lye, or they are not. The same for natural colourants.

Referring to the "low temperature" you mention:
- I like soaping at a higher temperature, mainly because I use a high% of solid oils/butters
- I never let my soaps gel on purpose; I don't see any benefits in that, and in certain cases I'd rather avoid gelling at all.
- the only "real" reaction you get in soaping is "saponification"; this reaction will take place, disregarding any temperatures or amounts.
How long it takes to complete, depends on starting temperature, additives and process (CP/HP/CPOP - whatever).

Coming back to the technical part, where I mentioned "indication":
(For convenience I'll stick with the fragrance example, but I could have mentioned "honey" as well.)
If dumping 25 grams of FO in a batch of 500 grams of fats gives you a major problem, like soap on a stick, you can imagine what the effect would be if you poured 250 grams of that FO in a 5 kilo pool.

So small problems could become major problems if you upgrade to a larger batch and ignore the signals you got when making the small batch.

On the other hand: tracing could take way longer with a bigger batch if you'd use the same stick blender .....

A note on (forced) gelling:
The only reason I could imagine one would do that, is to avoid partial gel (from an esthetical point of view). Oké some colours pop more after gelling, but other colours might lose intensity like (orange) mica.
Earlier unmoulding? I doubt it will make a difference; what you win on faster initial saponification, you lose on cool-down time.

IMHO/IME There are more risks than supposed advantages:
- extra heat may lead to vulcano's or "geodes" in the soap (honey, milks, sugar), colour morphing (milk), scent morphing (milks, sugars) and loss of fragrance.

But to each its own I guess.

 

[CrisMaz]

It will be basicly the same as long as the proportions are the same. This is why you make small batches in grams because you need more accuracy to keep the right proportions. Gel doesn't really matter that much when testing. You know gelled will be a little brighter but not drastically and really what you are looking for is whether it morphes out on you.

So there's really nothing major (if anything at all) that I can't find out in a smaller batch that would surprise me if I were to replicate the recipe in a 4, 5, 6 times larger batch?
I was window/monitor shopping all day today and found some recipes I tweaked and would love to try and the test batch idea really appealed to me

 

[Dorymae]

The trick is the proportions need to be the same. Think of soap making as one big chemical reaction. (Really it's many small chemical reactions but you get the point) If the proportions are the same it should react the same.

 

[CrisMaz]

The trick is the proportions need to be the same. Think of soap making as one big chemical reaction. (Really it's many small chemical reactions but you get the point) If the proportions are the same it should react the same.

It makes sense! I'm trying to get all sciency with this soap thing, but I'm very new, so it'll take a while!
Thanks for the clarification, suddenly I'm even more excited about my test batches

 

[new12soap]

I'm sorry but I disagree. I usually recommend the minimum batch size for a new soaper of 1.5 to 2lbs of oils. That is small enough to not waste too much if it doesn't turn out as well as you hoped, yet large enough to give you some room to cover any variations in your SAP values and in your measurements.

SAP values of oils are averages only as any agricultural product will vary from region to region and from year to year. The range of olive oil for instance is 184-196, a difference of over 6%. That is part of why it is so important to put at least a little superfat (or lye discount if you prefer) into your recipes, to build a buffer for those variations.

You didn't post your recipe, but I put a very basic oo/po/co recipe into soapcalc and calculated a 10oz batch. With a 5% superfat, you would use 40.864 grams of lye. For a 0% superfat it's 43.014, a difference of only 2 grams. That's if you measure in grams, in ounces that is less than 1/10 an ounce. Even the best digital kitchen scales are not accurate or reliable enough to give the sort of safety net that I want in my soaps.

As for how accurately can a smaller batch predict your results of a larger batch, well, not very IMO. Between differences in lye purity, SAP ranges, and measuring in anything other than a lab environment, you could have a soap with a 1% superfat or a soap that you made exactly the same way with a 10% superfat. How would you know?

Which brings me back around to the 2lb batch, large enough to give you some margin to cover the variables and test recipes with some accuracy, small enough to not waste materials or be hip-deep in soap you don't particularly want while perfecting both your recipes and your technique.

HTH

 

[Dorymae]

We can certainly disagree. I do feel my scale can accurately measure 2 grams, even 1 gram. I have made some very small batches to test colors and they have proven accurate for me. True I'm not a new soaper but I stand by what I said. If the proportions are the same and the ingredients are the same you should get the same results.

You talked about differences in lye and sap values, I agree with discrepancies however if your lye is from the same batch it should behave the same.

 

[CrisMaz]

As for how accurately can a smaller batch predict your results of a larger batch, well, not very IMO. Between differences in lye purity, SAP ranges, and measuring in anything other than a lab environment, you could have a soap with a 1% superfat or a soap that you made exactly the same way with a 10% superfat. How would you know?

You talked about differences in lye and sap values, I agree with discrepancies however if your lye is from the same batch it should behave the same.

Wouldn't the effect of discrepancies apply to ANY replicated recipe, not just a small batch vs large batch version of the same recipe?

 

[Dorymae]

Yes it would as far as the quality of the lye, and oils etc.
I think she was trying to say (and I could be completely wrong)that because with a smaller quantity there is less room for error that your chances of having an error are much higher. That combined with the discrepancy in things like lye make it more likely that you won't get an "exact replica".
I would agree with this to a point but I believe that the difference is negligible as long as you do your best to keep the proportions correct.

 

[new12soap]

Wouldn't the effect of discrepancies apply to ANY replicated recipe, not just a small batch vs large batch version of the same recipe?

IMO, no. Where a +/- of 1 gram (the margin of error on almost all home scales) in a very small batch could equal a 5% or greater discrepancy, in a larger batch it may only represent a 1% difference. As for lye impurities and variations in SAP values, again, larger batches give a much greater cushion, but that is why it is important to use reputable suppliers, reliable calculators, good equipment etc. And another good argument for learning good technique first, so if something does go wrong you are better able to identify it.

JM2C

 

[CrisMaz]

IMO, no. Where a +/- of 1 gram (the margin of error on almost all home scales) in a very small batch could equal a 5% or greater discrepancy, in a larger batch it may only represent a 1% difference. As for lye impurities and variations in SAP values, again, larger batches give a much greater cushion, but that is why it is important to use reputable suppliers, reliable calculators, good equipment etc. And another good argument for learning good technique first, so if something does go wrong you are better able to identify it.

JM2C

And this is how you learn! By asking questions and reading everybody's answers thanks so much, everyone is so helpful here