Is my plan to clean these bottles good enough?

January 31, 2011 7:20 AM

Glass bottles that were in hot water with some dilute generic store brand WD-40, so they got some residue on them. I need to make them safe and clean for flavored vodkas for human consumption. Please help!

In three days, I have some friends coming over for an activity. We will be infusing alcohol with different herbs for medicines and drinking.

I drink GT-Dave's kombucha, which comes in tall glass bottles. Since I have so many of the old bottles, I am planning to use them for the activity. The bottles have a sticky label on them. Most of the labels came off fine but there were a few I needed to use some generic store brand WD-40 on to get the filmy sticky label off.

The bottles were all soaking in a bucket of hot soapy water when I was taking the labels off. I tossed some of the bottles I used WD-40 on back into the bucket where they soaked with the rest of the bottles.

I realized that I had to get any possible WD-40 residue off of all of the bottles. So here is what I have done so far, as well as my future plan.

1. First I rinsed all the bottles off and soaked them in a brand new bath of hot soapy water.

2. After they had soaked for a little bit, I put a generous squirt of dr. bronner's soap in each bottle and then filled it to top with new hot water. I screwed the cap on each and set it on my counter.

3. The bottles are now sitting on my counter for the next hour or so with hot soapy water and the cap on.

4. After an hour on my counter, I will empty each bottle, rinse it out, and put it in my dishwasher.

5. I will take them out of the dishwasher, fill each again with new hot soapy water for another hour long soap.

6. Through the dishwasher once more.


After all of this, can I be sure that the bottles will be safe to use? Is my plan good enough? If not, what else do I need to make sure they are totally clean? The bottles already dont smell like WD-40 anymore.

posted by anonymous to science & nature (17 answers total)

From WD-40's MSDS:

The oral toxicity of this product is estimated to be greater than 5,000 mg/kg based on an assessment of the ingredients. This product is not classified as toxic by established criteria.

You've already cleaned off the residue, any tiny amounts left are not a hazard.
posted by odinsdream at 7:25 AM on January 31, 2011

You're fretting over almost nothing. Glass is not a sponge; it's easy to clean. After you've washed it, if it looks clean, feels clean and smells clean, it is fine.
posted by jon1270 at 7:34 AM on January 31, 2011

If you want them sterile, go to your local brewing supply store and pick up some PBW (Powdered Brewery Wash).
posted by brand-gnu at 7:39 AM on January 31, 2011

next time, to get labels off, put them in boiling water, but don't let water get inside the bottle...

my uncle makes wine and does this for all bottles that he reuses to get other labels off, if he gets water into the bottle itself, he throws them out.... not worth the hassle.
posted by fozzie33 at 7:43 AM on January 31, 2011

To get the mineral oil (WD-40) to dissolve in water, you need a soap with some surfactants, and possibly some oil content (I'm thinking orange GoJo). I'm not sure the Dr. Bronners is gonna do a good job, but whatever you use in your dishwasher is probably fine.

Additionally, for removing labels in the future, wear gloves and use an acetone-soaked rag on the outside of the bottle only. This will prevent internal contamination and do a much better label removal job than WD-40 or hot water. It is somewhat less awful than the hexane in your WD-40, but a hell of a lot more effective at dissolving glues and residue.
posted by fake at 7:43 AM on January 31, 2011 [3 favorites]

While it seems odd to promote one of the most commercially successful products out there, Dawn dishwashing soap is excellent at removing oils. The key is to no dilute it very much. Dilute it as little as possible to allow it to coat the inside surfaces and let it sit for a while. Then rinse and run through the dishwasher.
posted by rtimmel at 7:45 AM on January 31, 2011

I think you should be less concerned with toxicity or sterilization and more concerned with the taste that the residue may impart on the product. I'd run it through the dish washer a few times on the sterilize cycle (without any soap) and give it a good smell once they're dry. If you don't smell any WD40 you're good to go.
posted by pwb503 at 8:08 AM on January 31, 2011

You should be fine; if you're still worried, try the "regimen" I use for cleaning bottles that I'll be filling with delicious home-made booze:

1 - soak in oxy-clean solution until labels slide right off

2 - rinse clean, then soak in food-grade sanitizing solution for a couple minutes - I use 'Star-San' which is no-rinse

But, honestly? You should be fine. Don't psyche yourself out trying to taste for things that aren't there :)
posted by jtron at 8:17 AM on January 31, 2011

I suspect that vigorously shaking the bottles with soapy water inside will have far greater effect in removing oil than merely letting them sit (no matter how long), but I'm no soap scientist.
posted by astrochimp at 8:53 AM on January 31, 2011

Here's how an environmental scientist who has to wrestle with this particular problem, removing oil and surfactant residues from glass, handles it (yes, I have a PhD in bottle washing):

1. Wash everything with hot water and lots of dishsoap, bottles and caps.
2. Rinse with hot water until all soapy residue is gone. The hotter the water, the better.
3. After that, rinse the outsides of the bottles, then the insides, making sure that the water touch all of the inside surface of the bottle. Shaking or rolling the bottle with water in it works great. Empty the bottle.
4. Repeat step 3 two more times.
5. Air dry.

What's happening: Steps 1 and 2 remove most of the contamination. In step 3, each clean rinse removes 90% of what's left. Three rinses removes 99.9% (0.9x0.9x0.9) of the remainder, clean enough to be certain that you'll have no off tastes in your alcohol infusions.

I use exactly this method when we make wine and it works great.
posted by bonehead at 9:19 AM on January 31, 2011 [7 favorites]

BTW, I'm not 100% happy with trusting a dishwaher with narrow-mouth bottles. Call me over-cautious, but I think hand-washing does a better job for the insides of tall, narrow containers than a house-hold dishwasher. The outsides will get clean, but I'm less confident that the insides get a good look at the soap and water in the machines.
posted by bonehead at 9:38 AM on January 31, 2011

Ammonia mixed with water is an excellent degreaser, and you don't need a lot; start with 1/4 cup ammonia to a gallon of warm water. It rinses away very easily. Usually, it's found on a lower shelf in a supermarket's cleaning-supplies aisle. I wear gloves with even a mild solution, because it's very alkaline.
posted by wryly at 9:58 AM on January 31, 2011

...use an acetone-soaked rag on the outside of the bottle only. This will prevent internal contamination and do a much better label removal job than WD-40 or hot water. It is somewhat less awful than the hexane in your WD-40, but a hell of a lot more effective at dissolving glues and residue.

Acetone is also miscible with water (unlike hexane), so a rinse or two afterwards effectively removes it, even if you get it inside. In fact, it's a good alternate solution (no pun intended) to removing the WD-40, since it's also miscible with most liquid organics to some degree.
posted by solotoro at 10:09 AM on January 31, 2011 [1 favorite]

It sounds to me like you've done a fine job of removing the WD-40, now I would be concerned about making sure you rinse all the soap out of the inside of the bottles, which can be pretty tricky in my experience. I would just rinse them with clean hot water after the dishwasher cycle, instead of adding more soap.
posted by purpletangerine at 10:57 AM on January 31, 2011

90% rubbing alcohol will degrease just about anything.
posted by thatguyjeff at 11:03 AM on January 31, 2011

For cleaning-up bottles for homebrewing and infused vodka and pre-mixed cocktails, I use an ammonia solution to take the labels off (maybe 1/2cup household ammonia in 4gal water, soak for a day or two) then rinse with hot water (scrape if necessary). For homebrewing, bottles then gets a rinse with iodophor sanitizer.

I find that the dishwasher tends to kick particulate matter into the bottle, where it dries and bakes and becomes impossible to clear.

If there is anything inside the bottle, I'll find another bottle (maybe use a bottle brush, before the cleaning above).
posted by Prince_of_Cups at 1:32 PM on January 31, 2011

Are you super paranoid? If so, fill a plastic trash can with a dilute bleach solution, submerge the bottles, let them sit overnight, then rinse a few times with hot water. Otherwise, run them through the super icky pots cycle in your dishwasher.
posted by obiwanwasabi at 4:35 PM on January 31, 2011