Clear Glass vs. Dark Glass

[kmcain137]

First newbie post, so be gentle I have been fermenting cider for a little while now. What I produce is very basic and on a very small scale as I learn. I went from growlers to gallon jugs; all of them are clear glass containers. I have a number of dark glass beer growlers that I would love to use in experimentation. Does it matter? Does yeast ferment any differently in light vs dark? My gut reaction is that as long as it has sugar and the temp is stable, yeast could care less. But, I also bought a Sega Saturn one time and learned my lesson with going solely off of gut reactions. Thoughts?

 

[DBhomebrew]

Brown/amber glass reduces UV intrusion. A big deal for hopped beer, less of an issue with cider. But, UV is UV. We all could use less of it. Inside, no natural light, clear is totally fine.

 

[kmcain137]

Brown/amber glass reduces UV intrusion. A big deal for hopped beer, less of an issue with cider. But, UV is UV. We all could use less of it. Inside, no natural light, clear is totally fine.

This is very helpful! I haven't given much thought to the room / lighting where I'm doing the fermenting. I can just imagine the conversation with my wife now about how we need to build a dedicated brew room <laughing>! "Honey, you're going to love this idea." All joking aside, thanks for the helpful reply!

 

[tracer bullet]

When I bottled beer I did brown bottles for the UV reasons for most beer, but always had a few clear ones as well just so I could visually see progress, changes, and so on. Just a couple per case.

I wouldn't throw away clear bottles, but I also wouldn't take them on picnics if I had a choice.

 

[CharlaineC]

IMOP If you're cultivating yeast don't use clear. Back when I cultivated my own I had a number of bad experiences with clear and light causing either rapid uncontrollable growth or the uv killed off the yeast. I have had much better results with brown and amber bottles.

Bottling ciders clear is okay if you're not aging the cider long and in total darkness. Otherwise, i'd stick to amber

 

[McMullan]

Yeast cells don't need sunlight to grow so it's not recommended to culture them in direct sunlight. In the wild, yeast often colonise trees and other plants therefore exposure to UV is common. Like most living organisms enjoying themselves under the sun, active yeast cells synthesise UV protection compounds. I'm not sure what these compounds taste like, but I don't see any good reason to be promoting production of yeast sunblock when the aim is to ferment wort in the dark. Probably best to culture yeast starters in a dark cupboard, incubator or poorly-lit corner. We use clear glass for culturing vessels so we can visually monitor what's going on. Making sure there's activity, biomass is accumulating, no noticeable contamination, etc.

 

[Jacob_Marley]

Storage always needs to be in the dark to avoid your product becoming "light struck".
If you use clear bottles, just be prepared to store them in a case (cardboard or otherwise).
Fermenting vessels and secondaries should also be generally kept in a room where there is no ongoing sunlight and/or fluorescent light, while in use.

 

[Raptor99]

It is important to avoid all light, or only sunlight (UV)? After I bit of research, I learned that fluorescent lights emit a small amount of UV (a tiny fraction of UV present in sunlight), and that LED lights do not emit any UV. So if UV is the problem, then clear carboys would be fine in a room illuminated by LED lights.

 

[Jacob_Marley]

I think just the UV is the problem with wine/cider.

Also, there is less riboflavin in cider than grape wine (riboflavin is one of the two culprits in wine becoming light struck) ... so cider is a bit safer in that regard.
And ... the reason white wine is more problematic is because the tannins in red wine bind to the riboflavin and make it more unavailable ... so to the extent that one's cider has at leas a little bit of tannin in it that helps just a tiny bit too.

All in all, I'd guess that 100% LED lights around cider in clear containers is safe from the problem.