Filter vs shortwave UVC

Anyone have any experience using shortwave UVC to stabilize fermentation? I have the ability to filter, however due to liquid loss in the filter, am considering UVC Sterilization to kill yeast for halting fermentation.

I currently have a UVC light from another project, just not sure of the best way to pass the fermented beverage through the light box. Thought of coiled tubing, however it seems some plastics filter the UV light.

zazbnf said:

Anyone have any experience using shortwave UVC to stabilize fermentation? I have the ability to filter, however due to liquid loss in the filter, am considering UVC Sterilization to kill yeast for halting fermentation.

I currently have a UVC light from another project, just not sure of the best way to pass the fermented beverage through the light box. Thought of coiled tubing, however it seems some plastics filter the UV light.

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Uh, wouldn't that be a big no no for your hops? Plus, why do you think you need to go that far in sterilizing your beer?

zazbnf said:

Anyone have any experience using shortwave UVC to stabilize fermentation? I have the ability to filter, however due to liquid loss in the filter, am considering UVC Sterilization to kill yeast for halting fermentation.

I currently have a UVC light from another project, just not sure of the best way to pass the fermented beverage through the light box. Thought of coiled tubing, however it seems some plastics filter the UV light.

Click to expand...

ALL plastics have UV stabilizers that strongly filter UVB and UVC. Even glass will be a problem. I've had to use fused silica for 310nm. I did have some plastic lenses made from a special polymer that passed UVB once... I still have some of the raw resin from that.

Sorry, I know that's no help. You can buy UV sterilizers for fish tanks and home sterilization, but I wonder how well they work. I think they typically use fluorescent lamps.

afr0byte said:

Uh, wouldn't that be a big no no for your hops? Plus, why do you think you need to go that far in sterilizing your beer?

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Er, yea, there is that too. Der.

afr0byte said:

Uh, wouldn't that be a big no no for your hops? Plus, why do you think you need to go that far in sterilizing your beer?

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I seem to recall that the skunking reaction occurs in a narrow range of wavelength. Was it 640 nM? If the UV sterilizer operated in another range, this might work without skunking.

mabrungard said:

I seem to recall that the skunking reaction occurs in a narrow range of wavelength. Was it 640 nM? If the UV sterilizer operated in another range, this might work without skunking.

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Huh, I'm not sure. I think I remember AJ talking about the specific wavelengths in a thread on here, and 640nM sounds in the ballpark, but truthfully I had forgotten about it until you mentioned it. Btw, I'm going to do a sample mash somewhat similar to the mash from the thread about EZ water and Bru'n Water being so different (I'm doing a mild on Saturday). I'll see if diluting 1:1 with my tap water (214 mg/L alkalinity as CaCO3) is enough, assuming a Ca of ~55mg/L. Bru'n water estimates a 5.4pH.

I found this in BYO: "There are numerous references in the brewing literature stating that light ranging from 350–520 nm results in skunky beer. That covers the upper portion of the UV light range and visible light from violet to green, including blue."

afr0byte said:

I found this in BYO: "There are numerous references in the brewing literature stating that light ranging from 350–520 nm results in skunky beer. That covers the upper portion of the UV light range and visible light from violet to green, including blue."

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I'd make a small bet that even shorter wavelengths would have an effect, and probably a greater effect. As the wavelength gets shorter, the light energy increases.

afr0byte said:

I'll see if diluting 1:1 with my tap water (214 mg/L alkalinity as CaCO3) is enough, assuming a Ca of ~55mg/L. Bru'n water estimates a 5.4pH.

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Since this is a brown to black beer, there has to be some roast. And I expect that the recipe includes a bit of crystal too. The 100 ppm alkalinity might be OK for mash pH purposes. The result seems reasonable in my experience.

mabrungard said:

Since this is a brown to black beer, there has to be some roast. And I expect that the recipe includes a bit of crystal too. The 100 ppm alkalinity might be OK for mash pH purposes. The result seems reasonable in my experience.

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We shall find out. It has some crystal 60 (9%), crystal 150 (5%), and a bit of brown (3%) and chocolate (2%).

passedpawn said:

ALL plastics have UV stabilizers that strongly filter UVB and UVC. Even glass will be a problem. I've had to use fused silica for 310nm. I did have some plastic lenses made from a special polymer that passed UVB once... I still have some of the raw resin from that.

Sorry, I know that's no help. You can buy UV sterilizers for fish tanks and home sterilization, but I wonder how well they work. I think they typically use fluorescent lamps.

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That's what I was afraid of, don't really wan't to go with high dollar crystal glass. I guess I wasn't originally clear, my primary thought for this was for a cider I have in the fermenter that I wanted to halt fermentation on and wanted another option other than chemicals.

Hadn't considered the possibility of skunking beer, but now I want to try it Maybe I will brew a 2 gallon test batch of a pale ale, pull off a gallon to test under the UVC light and leave the other gallon as a control to see if it imparts noticable skunking.

If I could halt beer fermentation without ill effects, I did make a wonderful porter a while back that was awesome during an early sampling but later dried out as fermentation finished. Still good, but the early sample was better.

UVC is 290 nm - 100 nm

zazbnf said:

If I could halt beer fermentation without ill effects, I did make a wonderful porter a while back that was awesome during an early sampling but later dried out as fermentation finished. Still good, but the early sample was better.

UVC is 290 nm - 100 nm

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Why not just mash at a higher temperature and/or use a yeast that doesn't attenuate as much?