Will UV light kill yeast?

Never tried it, but use a UV light at work to sterilize the bio safety cabinets at work after setting up fungal cultures. Long enough exposure will kill most organisms.

 

UV-c light (the lower wavelengths of the UV range; lower wavelength=higher energy) is used to sanitize food contact surfaces. It will depend on intensity and length of exposure and whether you can direct sufficient intensity across the entire interior surface area. Technically, homebrewers sanitize, not sterilize. You might have difficulty sterilizing with this apparatus but maybe you can sanitize with it. I recommend investigating the details of the lamp (how many joules of UV-c is it putting out) and the food safety guidelines for this sort of thing. Or go the trial and error route -- the worst that will happen is you make a few batches of bad beer and give up.

 

I have re-used plastic from sour fermentations for clean fermentations successfully by leaving things soaking in sanitizer out in full sun for a couple of days. I would have an even higher confidence in getting glass sufficiently sanitized with the technique you are proposing, although I have no idea how the light compares to full sun in terms of sufficient intensity for killing off microbes.

 

You don't need to use a UV lamp to kill Brett in a glass carboy. Standard sanitation methods work fine.

 

for clarity, a UV filter will sterilize bacteria, but it will not kill them. Sterilization is just that, the bugs can not reproduce.

So if you have a large enough colony of bad bugs hanging out, they will indeed go to work doing the things you don't want them to do.

Use a mild bleach solution, or some other sterilization method.

You should also know that the low priced UV filters, the hand held battery operated kind, are just about worthless. Not enough intensity. The UV needs to be in a specific range and the residence time should be enough to get the job done.
Basically, UV has very little place in a homebrewery.
Cheers.

 

They are a higher risk. I've used all the above for brett/pedio/lacto beers and then for clean beers without an infection problem. That doesn't mean it can't happen.

 

Brett is yeast, just use starsan and be done

 

I should have added what everyone else is saying to my original comment. There is no need for the UV step, because Star-San works great on wild yeasts and bacteria in the brewhouse. But if you wanted to try your UV gizmo, because you think skipping the star san will save you money and time that is important to you, or just because you have access to this thing and want to play with it, then consider doing some trial runs and be prepared to mess up a few batches in the learning process.

 

In that case, it is an extra step that will add time to your brewing protocols and probably not add much value. Using two different sanitizing agents might contribute value if there were some infectious strains that resist star-san. If that were likely, there would have been reports on this forum on star-san resistant infection. I have no recollection of such a post in the past 10 years.

 

Sounds like yet another solution looking for a problem.

 

If you have already used starsan, then there should not be any brett to be affected by the UV. You are basically creating extra work for yourself. An economist would say that the costs are greater than the benefits, actually probably everyone would say that since there are no benefits