Sterilizing Vials/glassware: steam vs dry heat with absence of conventional oven

[Wolfman99]

I need to sterilize some glass ware.

The consensus I’ve found is dry heat or using an autoclave/pressure cooker both have some advantages and both will work, but it seems like the most common/preferred method is dry heat using a conventional oven.

I do not have access to a conventional oven. I am going to purchase a pressure cooker, or a stove top oven for sterilization. Which would be preferable?

As far as the method I’ll be using these Steps:



1) If Dry heat :
-Wash vials in detergent and distilled water
-rinse in bath of 70% isopropyl alcohol
-rinse in bath of distilled water
-2nd rinse in bath of distilled water
- place on sanitized cooking pan, covered in tin foil, open side up, covered loosely by a sheet of tin foil
*for this step, I’ve seen a couple suggested-
a) put in oven at 350degress F for 90 minutes ; or
b) put in oven for 500 degrees for 2 rounds of 60 minutes

-lastly, let vials stay in oven until cooled off to prevent condensation from cooling too fast, and then remove to fill and seal

- for the rubber stoppers, Ive seen some say let them soak in 70% alc for 20 minutes, and then they’re ready, but I’ve seen others say to put in oven for 20 minutes at 200 degrees after soaking in alcohol

2) for a pressure cooker

-place vials and stoppers inside, let the unit reach 15 psi, then run for 20 minutes after reaching that level.

It seems the steam method with a pressure cooker is less steps, and also has the benefit of being able to place the stoppers in with the vials....

I know many people suggest just getting pre sterilized vials, but I have other glass ware that needs sterilization so I included vials in the question.

Any feedback appreciated

 

[master.on]

The pressure cooker will leave them damp.
So it's better to spray them with 70% alcohol (can be either ethyl alcohol or IPA, better if alcohol is sterile filtered) and allow it to evaporate.
This both speeds up drying, and kills some additional bacteria.

 

[Wolfman99]

The pressure cooker will leave them damp.
So it's better to spray them with 70% alcohol (can be either ethyl alcohol or IPA, better if alcohol is sterile filtered) and allow it to evaporate.
This both speeds up drying, and kills some additional bacteria.

So your saying spray them with alcohol by putting the alcohol into a spray bottle, and then place them into the pressure cooker? Am I correct about 15 psi being necessary for sterilization?

Do you do the same for the stoppers as well as the glass vials

 

[master.on]

I meant to spray them with alcohol AFTER they come damp/wet out of the autoclave (unless your autoclave has a drying cycle).

 

[jstarks11]

I outlined this in another thead
In order to sterilize things for the purposes of homebrewing etc it is much like when you sterilize the pin site by simply SWABBING with Isopropanol pads!!! I use a bleach/Ammonia water solution to thoroughly wash all lab glass including vials with vial brushes. then use a tub of methanol to rinse AFTER a regular water rinse. The methanol rinses off any minerals from your water rinse (magnesium, calcium, sodium, etc). NO OPEN FLAMES!!! Methanol is Flammable. Now, once you have them rinsed, put all things upside down on new aluminum on a tray and slide in a preheated oven 250F and bake for an hour. IF something lives through that that resides in your kitchen then you must have some of those extremophiles from out of volcano's or the superheated bacteria spew that comes out of some parts of the bottom of the ocean. IE you will have sterile gear. When you take your glass out of the oven all turned upside down, you use a bottle of CAVIWIPES like baby wipes but alcohol instead. and each time you flip a vial or bottle over to use you just wipe the rim that was laying on the foil with a qick swipe of the alcohol wipe then fill stopper cap or filter or whatever you do. And be confident you are sterile, unless you are working in a dusty construction site where people are sanding sheetrock etc... Otherwise you are nice and sterile at this point.
You can raise the temp up in the baking process if it makes you feel better. Some will argue that 250F is not hot enough to kill bacteria. And of course there are some bacteria in this galaxie that can live through that temp for an hour. However, for the bacteria that SHOULD be in your kitchen, this is enough. SECONDLY this stage is NOT used to sterilize!!! That is what the bleach/ammonia and methanol thing does. Methanol is preffered to me cause it is cheaper than Ethanol (because it is not really drinkable) and it can be gotten Anhydrous whereas Ethanol is not anhydrous. I would not take out ALLLLL my glass at once. Only take out what you need at the time out of the oven. Swab part that was sitting on the foil and use. Then when you need more or to get something else out then repeat. This way, say if you are filling 150 vials, you pull them all out at once, then once you fill 20 vials then other 130 have higher suseptability for contamination by floating particles and things as they sit around and cool down. Pull out say 10 vials off your heated foil surface and transfer to another cool alcohol swabbed foil surface close to your work station. Then when you go to pull out another 10, swab your work area IE the foil you're placing the 10 vials on that your filling. Then pull out ten and place them in that spot. Repeat repeat.
Stoppers.... Same thing really. Wash, rinse, methanol rinse, place in stove. Another reason not to use 500F heat. This heat would melt the stoppers I presume. 250F is fine on stoppers. If you dont thoroughly dry stoppers they harbor condensation/humidity in the bowl part when left down. Then when you put the stopper in the vial and that humidity is in the stopper bowl it ends up turning your gear milky!
Just that little humidity in the stopper bowl will turn your gear milky yes.
But alas, bleach/ammonia scrub with lab brushes. Then regular water rinse just to get off the chemicals. Then a methanol rinse to get minerals off and further disinfect. No need for distilled water as the methanol alleviates minerals from the water rinse. Bake for drying purposes only and roll. Your GTG!!!

 

[jJjburton]

I outlined this in another thead
In order to sterilize things for the purposes of homebrewing etc it is much like when you sterilize the pin site by simply SWABBING with Isopropanol pads!!! I use a bleach/Ammonia water solution to thoroughly wash all lab glass including vials with vial brushes. then use a tub of methanol to rinse AFTER a regular water rinse. The methanol rinses off any minerals from your water rinse (magnesium, calcium, sodium, etc). NO OPEN FLAMES!!! Methanol is Flammable. Now, once you have them rinsed, put all things upside down on new aluminum on a tray and slide in a preheated oven 250F and bake for an hour. IF something lives through that that resides in your kitchen then you must have some of those extremophiles from out of volcano's or the superheated bacteria spew that comes out of some parts of the bottom of the ocean. IE you will have sterile gear. When you take your glass out of the oven all turned upside down, you use a bottle of CAVIWIPES like baby wipes but alcohol instead. and each time you flip a vial or bottle over to use you just wipe the rim that was laying on the foil with a qick swipe of the alcohol wipe then fill stopper cap or filter or whatever you do. And be confident you are sterile, unless you are working in a dusty construction site where people are sanding sheetrock etc... Otherwise you are nice and sterile at this point.
You can raise the temp up in the baking process if it makes you feel better. Some will argue that 250F is not hot enough to kill bacteria. And of course there are some bacteria in this galaxie that can live through that temp for an hour. However, for the bacteria that SHOULD be in your kitchen, this is enough. SECONDLY this stage is NOT used to sterilize!!! That is what the bleach/ammonia and methanol thing does. Methanol is preffered to me cause it is cheaper than Ethanol (because it is not really drinkable) and it can be gotten Anhydrous whereas Ethanol is not anhydrous. I would not take out ALLLLL my glass at once. Only take out what you need at the time out of the oven. Swab part that was sitting on the foil and use. Then when you need more or to get something else out then repeat. This way, say if you are filling 150 vials, you pull them all out at once, then once you fill 20 vials then other 130 have higher suseptability for contamination by floating particles and things as they sit around and cool down. Pull out say 10 vials off your heated foil surface and transfer to another cool alcohol swabbed foil surface close to your work station. Then when you go to pull out another 10, swab your work area IE the foil you're placing the 10 vials on that your filling. Then pull out ten and place them in that spot. Repeat repeat.
Stoppers.... Same thing really. Wash, rinse, methanol rinse, place in stove. Another reason not to use 500F heat. This heat would melt the stoppers I presume. 250F is fine on stoppers. If you dont thoroughly dry stoppers they harbor condensation/humidity in the bowl part when left down. Then when you put the stopper in the vial and that humidity is in the stopper bowl it ends up turning your gear milky!
Just that little humidity in the stopper bowl will turn your gear milky yes.
But alas, bleach/ammonia scrub with lab brushes. Then regular water rinse just to get off the chemicals. Then a methanol rinse to get minerals off and further disinfect. No need for distilled water as the methanol alleviates minerals from the water rinse. Bake for drying purposes only and roll. Your GTG!!!

Subbed as I was looking for this info

 

[Wolfman99]

I meant to spray them with alcohol AFTER they come damp/wet out of the autoclave (unless your autoclave has a drying cycle).

I assume after the pressure cooker , you’d put in the oven to dry off because of the dampness? I’ve heard that when using dry heat you’re supposed to rinse with distilled water after the alcohol, because the alcohol will leave a residue.

Is it ok to spray with alcohol after pressure cooking then put in oven to dry?

 

[jstarks11]

I assume after the pressure cooker , you’d put in the oven to dry off because of the dampness? I’ve heard that when using dry heat you’re supposed to rinse with distilled water after the alcohol, because the alcohol will leave a residue.

Is it ok to spray with alcohol after pressure cooking then put in oven to dry?

I'll be honest with you. I have some experience in the lab. College. Got a degree in science. NOT a chemistry degree but with a science degree you take quite a bit of chemistry. And from my experience, when using pure alcohol like methyl alcohol and even ethanol there is no residue. I tell you what I do and it works GREAT. I wash everything, regular water, which would have mineral residue. IE water spots. Calcium, Magnesium, Potassium, Sodium... But you just take you a tub of clean NEW methyl alcohol, and as you clean and rinse and shake as much water off as you can, throw things in this tub of alcohol. Then when you have everything washed, start pulling out those items (with gloves on) out of the alcohol and put direct DOWN on a sterile alcohol cleaned tray and then put in your oven. Bake. That shit always comes out crystal clear.
Also, you know what is in WINDEX that keeps it from streaking up glass??? Ammonia!!! So, presumably.... although I have never done this.... You may be able to substitute the tub of alcohol with CLEAR ammonia. Drop your stuff in it, then into the oven upside down... Ammonia would in theory keep things from spotting up too. Just not sure if there is minerals in the ammonia that would leave trace deposits...

 

[jJjburton]

I'll be honest with you. I have some experience in the lab. College. Got a degree in science. NOT a chemistry degree but with a science degree you take quite a bit of chemistry. And from my experience, when using pure alcohol like methyl alcohol and even ethanol there is no residue. I tell you what I do and it works GREAT. I wash everything, regular water, which would have mineral residue. IE water spots. Calcium, Magnesium, Potassium, Sodium... But you just take you a tub of clean NEW methyl alcohol, and as you clean and rinse and shake as much water off as you can, throw things in this tub of alcohol. Then when you have everything washed, start pulling out those items (with gloves on) out of the alcohol and put direct DOWN on a sterile alcohol cleaned tray and then put in your oven. Bake. That shit always comes out crystal clear.
Also, you know what is in WINDEX that keeps it from streaking up glass??? Ammonia!!! So, presumably.... although I have never done this.... You may be able to substitute the tub of alcohol with CLEAR ammonia. Drop your stuff in it, then into the oven upside down... Ammonia would in theory keep things from spotting up too. Just not sure if there is minerals in the ammonia that would leave trace deposits...

Would the alcohol create a fire if still wet on glass and put in oven?

 

[master.on]

Of course, you shouldn't put alcohol (or anything flammable in the oven).

You can spray some alcohol to speed up drying
but you must allow it to dry inside some large enclosed, sterile jar to keep sterility.
Don't just allow it to air dry in the open, as some bacteria may "land" on it.

 

[jstarks11]

When I pull the washed items out of my alcohol bath I SHAKE what little drops of alcohol are on said items off, just a couple quick slings, and then go straight into a BAKE. In the oven. Oven CLEANED and pristine!!! With the oven on and set at 200 plus degrees and been on for the duration of your cleaning etc... There is no living bacteria etc floating around in it etc.... As long as you just don't live in SQUALOR and filth man, you shake that alcohol off with couple slings of wrist and drop face down on your alcohol sterile surface in your oven, there will be no ignition no flames. I do this for all my brewing adventures since 2008 and have never had an infection or major PIP even. No lumps, swelling. Matter of fact, I just pinned 2 hours ago. This technique is not laboratory approved etc but if you are a clean person and pay attention to details like I do, it works just as good as any lab. I always keep things face down, no floating particles are making their way into vials collection bottles/flasks. I'm quick about things, I don't linger and hold things out in open, things go quickly into the oven. Oven is PRISTINE clean. Top and bottom oven, top is used for food, bottom is used for gear. I mean, you have to use some common sense too but it's really not as detrimental as it seems. Just be cautious and you will never experience dirty gear. Besides, I have seen over the years, UGL busts and looked at the background pictures of the brewing environments of POPULAR UGL's and their brewing environment and these , some of them, are labs that brewed for thousands and never had problems and some of their environments were dispicable!!!
For example, if you swab your ass with alcohol, fan it dry, then swab your vial top, then fan it dry then suck gear up, then inject then plunge, if it were true that floating particles and the like were that likely to cause contamination, then people would get infection rampant just from that process, the pinning process cause there is AMPLE time that the pin sight, needle, vial top, etc are all exposed to floating particles and would then in turn be pumped into your body ON SIGHT.... Just not happening...

 

[jstarks11]

Would the alcohol create a fire if still wet on glass and put in oven?

To reiterate, just a dampness, NOT DRIPPING WET, but a little dampness of alcohol on the vial or media bottle will NOT cause a flame or ignition placing it in the oven. Temp from 200-220 roughly. Just try it for yourself. Preheat your oven to 220, then take a vial and Isopropanol or Iso Propyl Alcohol 90% and dip the vial in alcohol fling a few time with your wrist and shake the most of alcohol off while holding vial opening pointed at ground. Then put STRAIGHT into oven. No flame, No ignition. You will even see drops here and there drip on the tray and start sizzling like water does the same and it just quickly evaporates and is done!!! No ignition.