Does Goat Milk Soap Go Bad?

goat milk soap

I made my first ever goat milk soap way back in 2005. I initially made three batches just for my family. I made Oatmeal Milk & Honey, Vanilla, and Peppermint. And I still have some of the original bars today.

Oatmeal Milk & Honey Goat Milk Soap
"I love the Oatmeal Milk & Honey. So smooth and smells awesome" - Karen R.

Those soaps are over 15 years old and they're still good. In fact, one could say they're even better than when I first made them!

How is that possible?

It's possible because properly made goat milk soap does not go bad. It will not spoil. And it will not expire. Instead, goat milk soap actually gets better as it ages.

What happens to the Milk in Goat Milk Soap?

Because one of the main ingredients in goat milk soap is (obviously) goat milk, it's easy to think that the milk could spoil and ruin the soap.

But the beauty of the saponification (soapmaking) reaction, is that it actually converts the milk molecules into soap. Which means there is no "milk" actually left - it has all been turned into soap.

Pouring goat milk soap into molds
"Love the Honeysuckle soap! The scent really stands out in the shower. Becomes more subtle as it dries on my skin. Leaves my skin soft and smooth thanks to the natural exfoliant just like I have come to expect from all my GMS soaps. Thank you!" - Joyce M.

But even though there is no goat milk leftover in the finished soap, that doesn't mean it has lost all the awesome goat milk benefits. Those benefits remain! The lactic acid (an alpha-hydroxy acid) in goat milk, the vitamins and minerals in goat milk, and of course the creamy butterfat goodness all remain in the soap to help nourish, moisturize, and protect your skin.

And even though there is lots of healthy raw goat milk in our soap, there is no need to fear that the milk will grow any harmful bacteria, yeast, or mold. Because the milk is no longer liquid - it has been turned into soap!

If you're wondering how this happens in more detail, you can read more about the amazing saponification process.

Does Goat Milk Soap Expire?

Because the raw goat milk has all been saponified and turned into soap, goat milk soap will never actually expire.

An important step to making the soap last as long as possible is the curing process. During the curing process, two main events take place.

First - the moisture in the soap evaporates. When soap is first made all the ingredients are mixed together until the soap starts to get thick, like pudding. Once it reaches this point (called "trace") the saponification chemical reaction has begun and the soap can no longer be separated out into its individual ingredients.

When trace is reached, we pour the soap into our soap molds. Many soapmakers use a block mold - which is just what it sounds like - a big block.

At Goat Milk Stuff, we find that these block molds can overheat and negatively impact the quality of the soap. So instead we use open tray-type molds. The soap sits in these molds overnight for about 24 hours.

Colter stacking trays of goat milk soap
"LOVE, LOVE, LOVE the Sandalwood Goat Milk Soap! Very light fragrance, which is nice! Soap leaves skin so soft." - Sharon W.

At this point, the soap is hard enough to unmold and cut.

But it is still very soft. So the soap is placed on curing racks that provide a lot of airflow to the individual bars. We also use fans that circulate the air around the soaps as well as dehumidifiers to reduce the moisture in the air.

We do this because we want as much moisture as possible to evaporate from the soaps. As the soaps cure, and more moisture evaporates, the soaps get harder. The soaps do lose some water weight, which is why we don't weigh them until they are six weeks old. But an older lighter bar will often last longer than a newer heavier bar of soap.

Second - the saponification reaction continues to occur during the curing process. In reality, saponification will continue to to occur during the life of the soap.

Picture a typical bell curve. The bulk of the saponification reaction occurs during the first 6 weeks of the life of goat milk soap. But there is a long tail to the curve which means saponification will continue over time.

Unlike many soapmakers, we don't add any artificial heat during this curing process. Our tests show that soap allowed to cure around room temperature is better for your skin than soap where heat artificially speeds up the curing process.

A slow, steady cure is what's best for soap. As the curing process takes place - goat milk soap gets harder, more gentle, and lasts longer.

Castile Goat Milk Soap
"Love the Castile Olive Oil soap! So gentle on skin." - Arlene S.

Does Goat Milk Soap Have to Be Refrigerated?

Because the goat milk has all been turned into soap, there is no need to refrigerate your goat milk soap. There is no goat milk left to spoil so refrigeration is not needed.

And because there is no milk left to spoil, bar soaps do not require any chemical preservatives to keep it safe.

Right now, we're talking about goat milk soap, but keep in mind that this is the reason that we make solid goat milk lotion (and not liquid goat milk lotion). Solid lotion is safer for you because there is no liquid environment that can grow harmful bacteria.

Michael with Goat Milk Solid Lotion
"I love the almond fragrance and I am enjoying using the Almond lotion stick very much! Thank you so much for creating this wonderful product!" - Theresa H.

How to Store Goat Milk Soap?

We always recommend that your goat milk soap be stored out of direct heat and direct sunlight. It is best to store it in a place where it can get some airflow. And lower humidity locations are preferred over higher humidity storage locations so that the soap always continues to dry out.

We never recommend storing your soaps in plastic as this traps the moisture around your soap and does not allow it to properly continue to cure. Storing in paper, cotton, or cardboard is always preferable to plastic.

And if your soap doesn't get a lot of airflow, just turn them over every once in a while and expose a different side to the air.

What is the Best Age to Use a Soap?

The optimal age to use your soap will depend on your preferences. The goat milk soap itself will get better as it ages. It will get harder and it will last longer the older it is.

But - and this is a big "but" for anyone who loves strongly scented soap - any added scent will start to fade around 9-12 months after the soap has been made (and not after it was purchased).

At Goat Milk Stuff, our goal is to sell our soaps between 8-12 weeks old. This gives the soap enough time to age, but it also gives you plenty of time to enjoy the scent.

Black Raspberry Goat Milk Soap
"We love the scent of the Black Raspberry! Most of all we love all your products. We love the clean ingredients of everything. Thanks so much for great products!" - Laura D.

If you prefer your soap unscented, the older the soap - the better! You can purchase your soap months if not years ahead. If you properly store it where it can get some airflow, it should become rock hard and last a very long time.

Washing hands with Purity Goat Milk Soap
"I buy the Purity items for my granddaughter as she has had issues with skin rashes on different parts of her body. Her parents love the all natural ingredients and the fact that the products have no fragrance. Purity is very gentle on her skin." - Patricia C.

Is all Goat Milk Soap Safe?

I made soap for my family for 3 years before I started selling it to others. During that time, I put my engineering education to work. I studied saponification. I learned the science of soapmaking and how it worked. I took notes and experimented with different ingredients and different amounts of ingredients. I tested how our soap formula held up over time.

So when I started selling it, I knew that we had a great product that was safe to use and wouldn't go bad.

When we took our soap to different festivals and craft fairs to sell it, I was shocked at some of the horror stories I heard.

I discovered that not every soapmaker practiced due diligence. I heard many stories of soapmakers who sold their very first batch of soap. But what was worse, I heard about people who had been hurt by soap.

When I say that goat milk soap will not go bad - what I really mean is that properly made goat milk soap will not go bad.

I wish it weren't reality, but the truth is that you can find a lot of poorly made soap out there.

Some soapmakers use bad formulas. Soap formulas have to be exact. The saponification reaction is an exact chemical formula. You need to know how much lye you need to turn all your ingredients into soap. Too much lye and the soap will be lye heavy and may burn people's skin. Too little lye and the ingredients will not all be turned into soap. This will produce soap that oozes or leaks.

One thing to note - sometimes a scent that has been added to a soap will "sweat". We sometimes see this happen with Vanilla. It's not pretty, but it is safe.

Vanilla Goat Milk Soap
"The Vanilla soap is just delicious! I love the smell & the way my skin feels. I love all the different soaps I’ve ordered! Thank you for your devotion to making quality product without the chemicals we do not want or need!" - Teresa H.

Some soapmakers use bad equipment. If a soapmaker is using a faulty scale, even with a good formula they can easily add too much or too little lye. At Goat Milk Stuff, we regularly test and calibrate our scales to make sure they are accurate. We also replace them on a schedule before they go bad.

Some soapmakers use bad ingredients. Poor quality ingredients or rancid oils will not produce the best soap. At Goat Milk Stuff, we have a strict protocol of using all of our ingredients in a timely manner. We store them in proper conditions to protect their shelf-life. We have also tested all of our ingredients to make sure they hold up over the life of the soap.

Will Your Goat Milk Stuff Soap Go Bad?

The only stories I have ever heard about our Goat Milk Stuff soaps going bad were from people who stored their soap in plastic.

One woman in Hawaii, purchased a bunch of soap during our Christmas holiday sales. She opened her box and put all the soap into a plastic bag, sealed it up, and stored it in her bathroom.

Over six months later, she went to get some and when she opened the bag, there was mold growing on her cotton bags that had rubbed all over the soap.

I share this story as a warning to not store your soap in plastic! We work so hard to send you dry, cured soap. Especially if you live in a humid area - plastic is your enemy. If you feel you really must store your soap in plastic, first remove the cotton bags and if possible, toss some desiccants (moisture absorbers) into the bag with the soaps.

But if you take care of your soap and store it properly - goat milk soap will not expire and it will not go bad.

At Goat Milk Stuff, our purpose is to bring you joy through the goodness of goat milk. We know that healthy skin is happy skin and we want to enable you to find the joy that healthy skin can bring. Goat milk soap is great for keeping your skin healthy and happy.

We work hard to make the best goat milk soap that will last a long time. Your properly stored Goat Milk Stuff soap can last for years and will only get better!

I have bars of soap that are 15 plus years old to prove it!

PJ & Crew

4 Responses

Goat Milk Stuff

Chris – You can put it on a soap dish or something where it can drain and dry out between showers. Hope that helps! PJ

Chris Koenig

How do you store the soap that you are using in the shower

Goat Milk Stuff

Jane – The liquid soap should also get better as it ages. Some of the scents will make the liquid soap look darker (especially anything containing vanilla) over time.

And sometimes, the soap will precipitate out over time. It can look like flecks or swirls in the bottle. That’s just undissolved soap you’re seeing. Shake well and use. 😊

Hope that helps!

Jane French

How about the liquid soap? How long does it last safely? Thx so much, love love love your products!

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