Does UV light kill wild airborne yeast?

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Pivzavod

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So I think I have some nasty wild yeast living inside my kitchen. Can I nuke it with a UV light sanitizer?
 

avibayer

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UV would have gnarly effects on your beer as well. Maybe try an air filter?
 

Bensiff

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Blasting your kitchen with UV is not going to do much more than a good wipe down with bleach water. If you have a lot of particulates in the air and you clean your house regularly I would check the air filter on your furnace and see if the ducting needs cleaned out in the vents. Turn your heater off while brewing so the air isn't being mixed up. An air purifier with ozone will do wonders too. However, it is not very likely to get a wild strain of yeast unless you have poor sanitation or are leaving the beer sitting around uncovered so I would first look at what you are doing for sanitizing your equipment...assuming your post was in regards to those wild yeast actually ruining a batch.
 
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Pivzavod

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But isnt blasting it with UV will also kill any bacteria that is in the air, that is not covered by wipe down with bleach water?

I do have a standalone air purifier which I guess will use in the kitchen. I had an infection in the past that made a batch taste like ass or at least would an ass would taste like imo. I want to keep multiple areas where beer is brewed and fermented cleaned out, including the air.
 

david_42

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Wild yeast is not UV-sensitive. Billions of years of exposure to the sun has killed the weak ones off.
 

malkore

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I agree with David, not to mention that a UV bulb isn't remotely as much UV light as sunlight.

I'd go for the bleach wipedown and HEPA filter on the furnace
 

Bensiff

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I will go back to my last post and reiterate that if you had an infection it is most likely not from the air but rather poorly sanitized equipment. I have hydrometer sample sitting in the garage two weeks open to the air...at first I was too lazy to clean it and now its kind of an expirement...anyway, not one trace of infection.

Given how you describe the off taste as "ass," if you live with male roommates I wouldn't rule out the possibility of a practicle joke on their part either :)
 
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Pivzavod

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I will go back to my last post and reiterate that if you had an infection it is most likely not from the air but rather poorly sanitized equipment. I have hydrometer sample sitting in the garage two weeks open to the air...at first I was too lazy to clean it and now its kind of an expirement...anyway, not one trace of infection.

Given how you describe the off taste as "ass," if you live with male roommates I wouldn't rule out the possibility of a practicle joke on their part either :)
No male roommates but it would be pretty gross if someone did that ;)
 

dirk_diggler

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how do you plan to wash the kitchen with uva and uvb? a hand-held unit? i think those take 20 seconds and need to be close to the surface.
 

itsme6582

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Wild yeast is not UV-sensitive. Billions of years of exposure to the sun has killed the weak ones off.
Does that mean that bacteria isn't sensitive to UV light as well? I think your logic is flawed. You may be right in the end but how you got there can't be right.
 

pjj2ba

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I'm pretty sure the right UV lamp will kill almost all yeast and bacteria. The sterile laminar flow hood in the lab is equiped with one that we use to kill everything. There may be a difference in exposure time to kill one versus the other. Actualy I do know that some microbes are more sensitive than others to UV light.

When I was in grad school there was a grad student I knew in another lab that had never worked in a hood before and she unknowingly turned on the UV light (versus the fluorescent) and proceeded to do several hours of work. She toasted her retinas and had to wear eyepatches for several days while her eyes healed.

That being said, this is not terribly practical, as you'd probably have to build some kind of flow cell so you could expose a small amout at a time while moving it past the UV light.
 

Brewinator

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I had a hand-held UV lamp I bought from Williams Brewing I used to sanitize my oxy beer caps. Unfortunately, during my latest bottling session, smoke came out of it, so that's dead. Looks like they don't sell it any more.
 

PiMaxC

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I think it could be useful for certain things, certainly not sterilizing everything in your kitchen. But if you had a cabinet set up with a reflective surface inside and high strength UV bulbs to put your caps, wine thief, bottles, auto siphon, tubing, and stuff like that in it would make a great storage unit as well as a quick way to sanitize things before you need them, flip the switch on the side, wait about a minute, turn it off and then open it up and grab your stuff.

I got this idea from my chemistry labs in collage, we had a small version of those cabinets for our safety goggles, my professor would set a timer for 30 seconds and then we could grab a nice sterile pair of goggles before we went about our work.
 

Brewinator

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This is the device I got from Williams Brewing. Maybe used it 15-20 times, then it had a smoky meltdown.



Kinda sad, since it at least had me convinced that I was sanitizing my Oxy caps without moisture, even if it wasn't. I did a test of this thing somewhere that showed it killed 100% of pathogens after like 30 seconds.
 

cain_h

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I know this is an older thread but I thought some of the information I found this morning was quite interesting.

First it looks like a study was done in 1940 on the effect of UV light on the growth of yeast cells. You can find the article at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1265446/

My read of it is that apparently at certain dosages it will cause the cells to emit nitrogenous material in the form of amino-N possibly due in part to some cell injury. This extra nitrogen material actually promoted growth over a non radiated sample. I think this type of material is a similar effect to adding yeast nutrient which also contains organic and inorganic nitrogen sources. The experiment was carried out with a quartz mercury vapor lamp. Without knowing much about such lamps and the construction of the one used its hard to say if this effect was caused by UVA B or C or a combination. Obviously we don't was to strap UV lamps to our fermenters, although I think the glass would filter some of the UV, but it was interesting to see such an old study on the subject.

More to the point of this thread I did find a pdf ultraviolet fact sheet from a company called Hanovia that stated "For Example pharmaceutical industries require a dose of 32mJ/cm2 for their process water while the brewing industry require 50-60 mJ/cm2 to control wild yeast." So its a matter of Time x Intensity over the Area being radiated (distance from surface). It would be impracticle and dangerous for a homebrewer to try to irradiate their kitchen to such a level but...

I'm working on a little DIY project to build a 2' x 1' box similar to this one http://www.aircleansystems.com/app_pcr2.htm All in all I think it will end up costing around $150 for the lexan, $40 - $60 for two 18" 15w UVC bulbs and balasts, $32 for a 2' x 1' x 1" polypropylene base, plus cost for hinges screws timer etc. Considering such boxes run $1750+ I think its a decent investment.

I think I'm also going to attach a UVC/HEPA air system (probably $0 -$65 for parts) to make it a dual use dead air box/positive air pressure system also. Biggest expense will end up being the cart from homedepot or lowes to put it on.

Looks like most of the materials can be ordered from amazon and I believe the lexan sides should protect from the UV. Even if this is so ALWAYS BE CAREFUL WHEN USING UVC light. NEVER EXPOSE YOUR EYES and/or SKIN TO SUCH LIGHT. You can cause serious injury to yourself and others. I'll be installing a timer on the rig so it shuts off after it is done with its UVC cycle just in case. Most dead air systems seem to have timers set for 15 to 25 min. I'll probably run the air filter for 10 min to push air out then seal it and run the UVC cycle for 30 min.

But like a previous poster stated most labs use a small box to quickly irradiate equipment with UVC. The smaller the box and the stronger the bulb the quicker you get done.

I'll make a post with construction pictures as soon as I get all the pieces in and hopefully be able to do some check plates to see how different the environment is between my kitchen, the dead air box normally, and the positive pressure system turned on to verify the validity of this project.
 

cain_h

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Tried posting this once and didnt show so hopefully it doesnt double post...

I know this thread is a little old but I thought some of the information I found this morning might interest some folks.

First I found that a study was done in 1940 on the effect of UV light on yeast growth. The article can be found here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1265446/

The short and long of it seems to say that in certain conditions UV light can cause increase yeast growth. This seems to be caused by an extra amount of nitrogenous material in the form of amino-N being released into the sample. This release may be due to an injury response by some of the yeast cells. I guess this material would be similar to us adding organic nitrogen material found in yeast nutrient. Without knowing the construction of the quartz mercury vapor lamp being used in the experiment its hard to tell from the article if UVA, B or C or a combination was the cause. Obviously we don't want to go strapping UV lights to our fermenters although I think the glass would filter some of it out anyways. It is interesting to see such an old study on the subject though.

More to the point of this thread I did find a pdf ultraviolet fact sheet from a company called Hanovia that stated "For example pharmaceutical industries require a dose of 32 mJ/cm2 for their process water while the brewing industry require 50-60 mJ/cm2 to control wild yeast." So its just a matter of Time x Intensity over the Area being irradiated in order to kill wild yeast. Clearly it would be impractical and highly dangerous for a homebrewer to try to irradiated their kitchen to such a level but...

I am starting a DIY project to build a dead air box similar to this one http://www.aircleansystems.com/app_pcr2.htm Most of the parts can be bought straight from amazon and will be substantially cheaper than buying one of these units for $2000. The lexan will cost around $150, plus $32 for a sheet of 2' x 1' x 1" polypropylene (showed up yesterday) to act as the base, $40 - $60 for two 18" 15w UVC bulbs plus balasts, and add in costs for hinges and screws. I think I'm also going to rig up a UVC airfilter (http://www.guardiantechnologies.com/GG1000-Pluggable-UVC-Air-Sanitizer-Details.html) with a preaction HEPA filter to make it a dual use dead air box/positive pressure system for about $75 more.

The lexan should filter out the UVC light but even if this is the case you should ALWAYS BE CAREFUL WHEN USING UVC light. You can cause serious injury to yourself and others if not handled properly as a previous poster stated. As such I will be rigging a timer for the lights similar to the professional system. I figure since their systems have timers from 15 to 25 min typically I'll probably run the positive pressure system for 10 min to push all the old air out and then seal it and run the UVC cycle for 30 min.

As soon as I get the pieces in and build I'll post pictures of the construction in a new thread. Hopefully I can then make some check plates for the kitchen, the dead air box and the box with positive pressure system turned on to verify the validity of the project.
 

theredben

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I think it could be useful for certain things, certainly not sterilizing everything in your kitchen. But if you had a cabinet set up with a reflective surface inside and high strength UV bulbs to put your caps, wine thief, bottles, auto siphon, tubing, and stuff like that in it would make a great storage unit as well as a quick way to sanitize things before you need them, flip the switch on the side, wait about a minute, turn it off and then open it up and grab your stuff.

I got this idea from my chemistry labs in collage, we had a small version of those cabinets for our safety goggles, my professor would set a timer for 30 seconds and then we could grab a nice sterile pair of goggles before we went about our work.
This would be an excellent way to burn out your eyes! Seriously, UV light in doses that are high enough to sterilize things is extremely dangerous!
 

scubastan

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If your planning on using this to do sterile work with your yeast then you can do it for about $20-$40. Look up a "still air box" on google. Your 1st result will lead you to a site about growing magic mushrooms. They have some of the best information on building your own still air box or laminar flow hood.

I created my own still air box to do my agar and yeast work. Haven't had a single infection yet. I bought a big 40 gallon container and cut two arm holes, and then got some tyvek painters overalls and taped them onto the arm holes.

Basically you want to keep all the air inside the box clean and sterile. So I open the lid to my box, put in my petri dishes, flask(s), tools, etc. and and put the lid bag on. I then shrink wrap the lid to the box. Inside the box I have a small salad dressing sprayer/canister of sterile water and soap, and spray everything inside with a super fine mist. This is to trap any airbone yeast, dust, bacteria that might be floating inside the box. I let it sit for 10 minutes and then start my work.

***WARNING MAKE SURE YOU DONT HAVE ALCOHOL FUMES AND A FLAME INSIDE THE BOX, IT WILL IGNITE!

I use a small cigar jet lighter inside my box to flame sterilize my tools. So make sure if you do clean the inside of your box with Alcohol to let it air out completely before you start. *Thats why I use soapy water instead of alcohol. You can also use hydrogen peroxide but soapy water works and its cheaper.

In the past I've tested/experimented my box by opening a petri dish inside the box while I work, and left it open. and then re-closed it when I was done to see if I had any contamination. I ran 5 separate test and never had a contamination.

Test 1: sealed box, sprayed soapy water, let sit 20 minutes. Result no infection.
Test 2: sealed box, sprayed soapy water, sit 10 minutes. Result no contaminates
Test 3: sealed box, sprayed soapy water, sit 5 minutes. Result no contaminates
Test 4: sealed box, no soapy water, sit 5 minutes. Result no contaminates
Test 5: no saran wrap on lid, soapy water, sit 5 minutes. Results no contaminates

If you have any questions PM me, and I'll try to help.

I am starting a DIY project to build a dead air box similar to this one http://www.aircleansystems.com/app_pcr2.htm Most of the parts can be bought straight from amazon and will be substantially cheaper than buying one of these units for $2000. The lexan will cost around $150, plus $32 for a sheet of 2' x 1' x 1" polypropylene (showed up yesterday) to act as the base, $40 - $60 for two 18" 15w UVC bulbs plus balasts, and add in costs for hinges and screws. I think I'm also going to rig up a UVC airfilter (http://www.guardiantechnologies.com/GG1000-Pluggable-UVC-Air-Sanitizer-Details.html) with a preaction HEPA filter to make it a dual use dead air box/positive pressure system for about $75 more.

The lexan should filter out the UVC light but even if this is the case you should ALWAYS BE CAREFUL WHEN USING UVC light. You can cause serious injury to yourself and others if not handled properly as a previous poster stated. As such I will be rigging a timer for the lights similar to the professional system. I figure since their systems have timers from 15 to 25 min typically I'll probably run the positive pressure system for 10 min to push all the old air out and then seal it and run the UVC cycle for 30 min.

As soon as I get the pieces in and build I'll post pictures of the construction in a new thread. Hopefully I can then make some check plates for the kitchen, the dead air box and the box with positive pressure system turned on to verify the validity of the project.
 

pabloj13

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I'm pretty sure the right UV lamp will kill almost all yeast and bacteria. The sterile laminar flow hood in the lab is equiped with one that we use to kill everything. There may be a difference in exposure time to kill one versus the other. Actualy I do know that some microbes are more sensitive than others to UV light.

When I was in grad school there was a grad student I knew in another lab that had never worked in a hood before and she unknowingly turned on the UV light (versus the fluorescent) and proceeded to do several hours of work. She toasted her retinas and had to wear eyepatches for several days while her eyes healed.

That being said, this is not terribly practical, as you'd probably have to build some kind of flow cell so you could expose a small amout at a time while moving it past the UV light.
Sadly, I think those flow hood UV bulbs are more effective against retinas than microbes. The bulbs have a short half life and most labs don't replace them for years. I prefer bleach, ethanol, and good technique.
 

Peppers16

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Sorry but this all seems a bit over-the-top. I know brewers tend to be very keen on sanitation but nuking kitchens with UV and laboratory-style sterilization boxes seems too far!
As people are saying, a UV bulb is probably only useful if you hold it close to surfaces, so you might as well use a cloth and bleach. If your kitchen is 'harboring' wild yeast (dont they all to some extent?) They'll be on surfaces.
 

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