Preventing soda ash is a common struggle among cold-process soapmakers. Nothing ruins your beautiful swirls and intricate designs faster than unappealing white flakes ruining your soap! Before you scrape an entire batch or give up entirely, try experimenting with sodium lactate. Adding just a small amount of this effective yet gentle additive into your soap recipe may be the solution to stopping soda ash in its tracks. Let’s explore how sodium lactate works and my experiments testing different amounts to find the sweet spot for my recipe.

What is Sodium Lactate and How Is It Used in Soapmaking ?

Sodium lactate is a natural ingredient used in cold-process and hot-process soap making. It is the sodium salt of lactic acid, an organic compound produced during fermentation. In soap making, sodium lactate is used to harden bar soap, improve lathering, and prevent soda ash.

When added to a soap recipe in liquid form, sodium lactate lowers the water content in your batch. This makes it harder for water to evaporate from your soap bars. Evaporation is one of the main culprits behind soda ash, which are those unsightly white powdery deposits that can form on top of CP soap. Sodium lactate quite literally stops soda ash in its tracks.

The recommended usage rate for sodium lactate is typically 1 teaspoon per pound of soap oil in your batch. It can be added directly to your lye water solution during saponification. When added here, sodium lactate interacts with the various soapmaking oils once a trace occurs in your pot. This ultimately gives you a soap bar with more hardness and stability.

Sodium lactate also boosts lather, increases bubbly creaminess, and provides a smoother texture in cold and hot-process soaps. Natural humectant properties allow your soap to hold on to more moisture over time. Some soap makers even find it eliminates the need to discount water in their recipes!

How Sodium Lactate Prevents Soda Ash

Sodium Lactate’s Effect on pH

The mechanism behind how sodium lactate prevents soda ash formation has to do with pH. Fresh cold-process soap starts off highly alkaline, with a pH between 12 and 13. As your bars cure and oxidize over 4-6 weeks, the pH drops and becomes more neutral. If exposed to air too quickly, the oils in the soap can start to carbohydrate on the surface. This reaction causes soda ash.

By adding sodium lactate to your soap pot, you essentially stabilize and buffer the pH. This balanced pH environment keeps the saponification process gentle and controlled. Oils stay emulsified properly within the bar rather than separating and rising to the surface during cure. Essentially, sodium lactate lets your soap bars “set up” evenly so no soda ash crystals form.

Reducing Water Evaporation

The other way sodium lactate prevents ash is by drastically lowering water evaporation rates. We know that ash blooms because lighter fluid components float upward as excess moisture escapes. By holding onto water, sodium lactate stops this migration issue. Bars retain their moisture longer, keeping all the oils incorporated smoothly. Less evaporation also has the added bonus of reducing shrinkage cracks!

Experimenting with Amounts of Sodium Lactate

Testing Different Percentages

When first using sodium lactate, beginner and veteran soap makers alike should experiment with different use rates. Start by testing bars with sodium lactate additions at 0.5%, 1%, 2%, and 3% of your total oil weight. For a simple recipe using 1 pound of combined oils, this would mean starting trials with 1/2 teaspoon, 1 teaspoon, 2 teaspoons, and 3 teaspoons of sodium lactate. Compare test batches to a control soap without any additive as a baseline.

Finding the Optimal Amount

Observe how each batch sets up, hardens, and cures over a 4-week testing period. Check for visual qualities like color and creaminess, along with functional traits such as lather stability, hardness, and crack resistance. Analyze bars for any excess oil, texture issues, crumbliness, or sticky residue. Review your detailed notes and feedback to find the ideal percentage of sodium lactate for your recipe. Most soap makers settle on 1 teaspoon per 1 pound of oils as optimal, but individual preferences vary. Playing with different rates teaches you how sodium lactate interacts in your formula.

Troubleshooting Issues

Pay attention so you can troubleshoot any problems. For example, too much sodium lactate can accelerate the reaction or create a soap batter that overheats. Not enough sodium lactate may lead to partial soda ash formation during the cure. Keep an eye on your batches for odd textures, discoloration, shrinkage problems, or lather quirks. Running careful tests gives you authority over how sodium lactate performs in your soap pot!

Additional Tips for Using Sodium Lactate

Mixing Sodium Lactate Properly

To properly incorporate sodium lactate, first fully dissolve it in a small amount of distilled water. Then, add your sodium lactate solution directly to your lye water and give it a stir. This prevents clumping. Alternately, you can add powdered sodium lactate directly to your oils. The key is getting it fully blended before the trace happens.

Oils to Use

Sodium lactate works best with harder soap recipes, typically those containing at least 30–40% combined palm, tallow, or lard. Used in excess with all liquid oils, sodium lactate could make your bars too hard and cause cracking issues during cure. Strike a balance by formulating recipes with some hard and soft oils.

Effect on Trace

Depending on your recipe, sodium lactate may cause accelerated tracing. The ions interact with fatty acids in your oils, speeding up thickening. Be prepared for batter to reach trace faster, which also leads to quicker saponification. Don’t fret over traces of soap frosting as long as your bars themselves turn out. Just get sodium lactate blended in properly before light or medium trace during your sugar water stage.

Potential Downsides of Using Sodium Lactate

Accelerated Trace

As mentioned, adding sodium lactate can cause some soap batches to reach trace more quickly. The ions react with oils to speed up thickening. This accelerated tracing can make working with intricate designs or swirls more tricky.

Soap Texture Issues

If overused, sodium lactate may create bars that are too hard or brittle. This leads to issues like surface cracking or a gritty lather. Start conservatively with sodium lactate until you learn how it behaves.

Higher Costs

While it delivers useful benefits, sodium lactate is more expensive than other basic soap additives. Depending on your batch size and frequency, costs could add up over time. Evaluate if the extra expense fits your budget and priorities for a soda-ash-free bar.

Experimenting with sodium lactate allows cold-process soap makers to prevent soda ash. When used properly, it creates hard, professional bars that lather abundantly without unsightly white powder residue. Sodium lactate is a rewarding additive that gives soap makers confidence.

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