Homemade Hand Sanitizer Update

I’m always learning. And that’s a good thing even when it feels mildly annoying.

Like falling down and picking yourself up again.

Like learning that my original homemade hand sanitizer recipe might not have been up to proper germ killing standards.

My original homemade hand sanitizer recipe used a 50/50 ratio of 70% isopropyl alcohol to aloe vera gel. I used this hand sanitizer all last winter, was not sick a day, and liked it lots. BUT – then I received the following comment:

“I think it is extremely important to inform you that your sanitizer DOES NOT contain the required alcohol percentage to kill germs. You are using 70% alcohol and mixing it 50/50 with aloe gel. This, in theory says that your alcohol percentage is approximately 35%. This will NOT kill germs. You NEED 65-70% alcohol to make your sanitizer effective. If you are making this recipe, you will need to use 99%to 95% alcohol and less aloe/glycerin/other gels. With your recipe, all you get is a bottle of false security.”

OK, that called for some investigation.

INVESTIGATION BEGINS:

Q: Is this true? Do you need more than 50% alcohol?

A: Looks like a Yes. The current scientific research states that the alcohol concentration must be over 60% in order to kill microbes.

Q: So are the store bought varieties of hand sanitizer at this percentage of alcohol?

A: The Purell FAQ page lists their active ingredient as 62% ethyl alcohol.

Q: What’s Ethyl alcohol?

A: Pure grain alcohol. Ethanol. Like I think you can run your car on that stuff.

Q: What’s the difference between ethyl alcohol and isopropyl alcohol?

A: Not much. Basically they have a slightly different chemical structure.  There’s a shorter carbon chain on the ethyl alcohol.

Q: So is one better than the other?

A: Lots of scientific gobbledy gook. Can’t make sense of it all. Head swimming. Thinking about getting a snack.

INVESTIGATION ENDS.

homemade hand sanitizer

My investigation did take me far enough that I decided my original recipe needed some tweaking. Two things had to happen.

#1 – I needed to use the 99% Isopropyl Alcohol (instead of the 70%) to keep the alcohol percentage high enough; and

#2 – I needed to use 2 parts alcohol to 1 part aloe gel (instead of equal parts). This would result in an approximate 66% alcohol to 33% gel.

homemade hand sanitizer
My Test Batch

So I made a little test batch – AND – the disappointing thing is you get a much thinner mixture.

It didn’t stir together as nicely as my original mixture either. It really needed a good shaking once I had it in my pump bottle before it appeared to be mixed together well. It still rubbed into my hands nicely, however, and the alcohol smell fades away quickly.

The updated recipe measurements below should meet the prevailing wisdom on the needed strength of a hand sanitizer and is still quick and easy to whip up at home as needed.

How to Make Homemade Hand Sanitizer

Ingredients:
1/4 cup Aloe Vera Gel
1/2 cup 99% Isopropyl Alcohol

Place the aloe vera gel in a bowl. Add the alcohol slowly, stirring as you go to mix it into the aloe gel. Transfer the mixture to a small pump bottle and shake well.

* Note: You should be able to find the 99% Isopropyl Alcohol in drug stores in the same location as the 70% variety.

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65 Comments

    1. After some quick research on alcometers (which are intended to discern the alcohol content in distilled spirits for drinking), it looks like they are only accurate if the mixture is just alcohol, or alcohol and water. If other substances are mixed in (such as aloe juice), I’m not sure if it will be accurate.

  1. Everclear is ethanol or grain alcohol, available up to 95% concentration. There is an industrial process to synthesis ethyl alcohol. Yikes. I would stick with grain alcohol (corn in this case). 70%+ is effective at destroying Covid-19 from what I have read and is maybe more effective and less toxic than Isopropyl alcohol. But it is harder and more expensive to obtain (unless you have a high quality still ;-^). I am having a separation problem with my first batch. I will see if the pure Aloe gel separates overnight or combines. It is on the thin side. Producers use a dry polymer to make it thicken. It seems to apply just fine though and leaves the hands smooth, not dry. Use what is available to you as the bottom line. Glycerin can be used as a substitute for Aloe gel. If you can’t wash your hands with soap and water, this a critical alternative in this pandemic nightmare.

  2. Probably a stupid question, but can you use a gelatin product to thicken it without overly diluting the formula?

    1. Perhaps, but most gelatins are sold as powders that need to be diluted in wate, so the alcohol amount might need to be increased too to keep the percentage high enough.

  3. The blend ratio math is rather easy. Lets say you want to make 100 mls. of sanitizer and have 70% IPA. Just divide 70 by 60, the multiply answer by 100. This will give you the full amount of IPA mls for the solution. Take the full mls. tabulated then subtract 70. the result will be the amount of aloe vera you need to add to the solution to make a 60% alcohol strength sanitizer

    1. I think you would treat this like 70% rubbing alcohol. My calculations based on helpful info from another commenter, was to use 1/2 cup of the alcohol with 4 teaspoons of gel. This of course would make a very watery mixture, probably more suitable to a spray bottle, but it should then have a high enough alcohol content.

  4. Have you figured out how to make the finished product thicker, so it’s more like store-bought sanitizers?

  5. Does adding the alcohol slowing stirring keep the aloe from turning into a gross gloppy mess?

  6. No. It’s 50% rated because it’s already mixed/diluted with water. The bottles with higher ratings have less water already mixed in.

  7. I make my sanitizer using 2/3 cup of 99% alcohol(purchased in a gallon size from eBay), 1/3 cup of organic Aloe Vera gel(purchased online by searching wholesale aloe vera gel) and organic tea tree oil purchased from eBay) for it’s antibiotic properties and added moisture. It mixes extremely well and works perfectly in spray bottles.

  8. Isopropyl alcohol is poisonous, ethyl is not. Since some gets absorbed through your skin into your bloodstream every time you use it, always use ethyl.

  9. Sorry, your calculations are off. 66% alcohol isn’t 70% alcohol. Ever. The concentration is very important in order to disrupt the cell membrane leading to cell death.
    To make 1 pint, 480ml, the proportions are 340ml 99% alcohol and 140ml Aloe Vera gel.

    1. If I have Everclear 151 proof, 75.5% do I have to use it straight for sanitizing and disinfecting? Can I add a little aloe for hand sanitizer out water for spray? How much to prevent over diluting?

  10. I had the same problem with the aloe vera gel separating into clumps! After 2 failed batches, I researched the problem. I tried a 3rd batch and added the alcohol VERY slowly… about one Tbsp at a time and whisked each in thoroughly before adding another. After I had used up about half the alcohol, I started adding a bit more at a time. Using this method, it mixed fine with no clumps.

  11. I couldnt find 99% rubbing alcohol so I added about 1/16 th cup of grain alcohol to boost the %.. works great.

  12. Thank you for your research, if you can not find anything stronger than 60 percent alcohol I’m wondering if bacteria fighting Essential Oils like tea tree added to the recipe will work to help fight the recent virus.

  13. You can but all I got was lumpy hand sanitizer. The only reason for the Aloe is to moisturize. So I just put the rubbing alcohol in a little bottle. Use it to sanitize my hands then use the Aloe to moisturize.

    1. Chrissy, I read many resources indicated that 99% alcohol has to be diluted otherwise it would not kill the bacteria,. Something about the water killing the bacteria and pure alcohol only penetrating the outside shell. Google it:)

  14. I had same problem as 3 other commenters: Mary Hafner, G. Love, and Mary Chee — the aloe WILL NOT MIX with the alcohol (91% isopropyl alcohol and Trader Joe’s aloe gel). The aloe is completely separated in small bits and strands. Even put in sealed jar and shook hard for a long time. Result: just liquid and separated lumps and strands.

    Doesn’t anyone have a solution to this problem? I’m not the only one. My sister-in-law had same result, as did Jenn Fields from simplemost.com.
    https://www.simplemost.com/diy-hand-sanitizer-what-happened-when-i-made-some/

    1. Could it perhaps be the difference between 100% pure aloe gel and the gels that are not 100%? I did not have this problem when I made mine so I can’t say with certainty what’s causing it. I do note that in the article you referenced, she used 99% pure aloe gel.

  15. I’m unable to find the 99% alcohol— lucky to get the last 2 bottles of 70% at a small pharmacy, as all disinfectants have been snatched up. Do you know the correct amounts of gel to 70% alcohol?

  16. For 91% isopropyl alcohol, I would use 3 parts alcohol, 1 part aloe. That would get to your 70% ratio you need to disinfect. 60% for ethyl alcohol, 70% for isopropyl alcohol recommended. Good luck and stay safe.

  17. Same thing happened to me this morning and I spent a fortune on the aloe vera gel from a natural food store!

  18. I love this post. I have several aloe vera plants. And have used them for burns. Can I use the aloe vera from my plants for this?

  19. I had to order it on line. All stores here sold out. Much higher price then I wanted to spend but it is what is. Good luck

  20. I am only able to find 91% alcohol- I am wondering if this would work by using a higher amount of alchohol than the recipe calls for?

  21. This is helpful but it would even more helpful if you provided links to your sources so that your readers can do some of their own research.

  22. I keep trying to get the aloe to mix together but it separates from the alcohol what am I doing wrong I followed everything you said. Very watery cause aloe won’t mix

    1. You need to use quite a bit of alcohol in the mixture in order for the mixture to have a high enough alcohol content to be effective. And because rubbing alcohol is a liquid, the resulting mixture ends up being more watery than the store bought mixture.

  23. why does the aloe vera clump. Ive tried whipping, shaking, warming, but nothing works. The aloe vera is 100 % pure aloe vera gel and the isopropyl is 99%. ?

  24. Is there a trick my mixture is not gelified, I used 99% alcool and aloe Vera gel, 2 parts alcohol and one part gel. I added 2 drops Orange essential oil. Need to know why it is not gel.

  25. Ugh, clarifying a typing mistake below…

    Where it says, “two volume units (like two quarter cups) of pure isopropyl would weigh 1.57 units, and one volume unit would weigh 1 unit.”

    It should’ve said, “two volume units (like two quarter cups) of pure isopropyl would weigh 1.57 units, and one volume unit OF ALOE VERA GEL would weigh 1 unit.

  26. Just to clarify my previous comment, that’s assuming 100% pure isopropyl alcohol. Most of what you find at the drug store is 99%, 91%, or 70%.

    If you assume 99% isopropyl alcohol has a specific gravity of 0.787 and do the proper calculations, you find that the 1/2 cup 99% isopropyl + 1/4 cup aloe vera gel yields a 60.6% alcohol hand sanitizer. And that assumes you’ve measured the volumes very carefully and did it at the temperatures at which the specific gravities are listed. Also, remember that high concentration alcohols tend to pull moisture out of the air if left uncapped, further diluting them.

  27. I assume hand sanitizer is supposed to be a minimum of 60% alcohol *by weight*.
    Isopropyl has a specific gravity of about 0.786, or about 78.6% the weight of water for a given volume. Most of the aloe vera gels I’ve seen have a specific gravity of about 1.0, or about equal density of water. If the aloe vera gel doesn’t add any of its own alcohol, two volume units (like two quarter cups) of pure isopropyl would weigh 1.57 units, and one volume unit would weigh 1 unit. The resulting concentration of alcohol by weight would be 1.57 divided by 2.57 (1.57 + 1.0) = 0.61, or 61% alcohol. Just barely squeaks in as effective.

  28. You will get a higher percentage of alcohol in your hand sanitizer depending on how much alcohol (ethyl or isopropyl) is in your aloe vera gel. So if your aloe vera gel does not have any alcohol, it will be a 66% alcohol gel. If your aloe vera gel does contain alcohol, it will have a higher percentage. Not all aloe vera gels will state the percentage of alcohol so I can’t say what your final product will have. When it comes to bacteriocidal properties, a higher alcohol percentage is better. Mix in a well ventilated area as the 99% isopropyl is volatile.

    1. I have only used isopropyl alcohol for this recipe and so I can’t give any first-hand knowledge on substituting ethyl alcohol.

  29. I agree with the use of alcohol if you aren’t going to use an essential oil that will do the bug killing for you but I have found other recipes that do not use alcohol which is great for use with kids and/or for people use it a lot since the alcohol will dry your skin. And can intoxicate you slightly…

    You can find the recipe link, and many others, on my Pure, Safe and Beneficial Pinterest board here http://pinterest.com/pin/178595941443781660/