Light Affecting Beer

[datman510]

Hi Again,

i mentioned yesterday i was regulating temp by using a couple of flood lamps, now the heat side of things is working great but then i read sunlight can affect the beer would the same principle apply to my temp regulator? they are insanely bright.

thanks again

Laz

 

[Fourstar]

If there non-UV you're safe. UV rays break down the beer and 'skunk' it.

 

[datman510]

any idea how i would tell? i believe they are halogen globes? thanks for the quick reply

 

[Adamt]

I'm fairly sure UV light only affects beers with non-isomerised alpha acids. If you're brewing from a standardish kit that doesn't have hop flavour in it, you should be fine with the flourescent light. If you hopped it yourself, even if you boiled your hops for >60 minutes there will still be non-isomerised alpha acids present.

Edit: You'll know when you taste it.... or draw off a glass from your fermenter, leave it in the sun for 10-15 minutes (covered), then taste it. You'll know the taste.

 

[Fourstar]

According to wikipedia. Halogen are UV emitting. However some are low output OR have UV restricer lenes on them

at the end of the day, you're beer is getting exposed to UV = NOT GOOD.

turn them off would be the best bet.

 

[datman510]

what about ifi cover it with card so the heat gets through but not the bright light?

 

[Crunched]

If they're anything like the flood lights I have in my garage, a piece of card will catch fire in about 30 secs! You're cycling these lamps with some sort of thermostat right? Why not swap the lights with a heat belt? Would probably use a LOT less power also.

 

[Jamz]

You may want to look at replacing your lighting system with a fermenter heating belt which you'll be able to pick up at your local homebrew shop for around $40. However when yeast burn through all that sugar in your wort they produce heat and depending on how cold it gets in your area, just wrapping the fermenter up in blankets to keep that heat in might be enough to keep it warm. Keeping in mind you shouldn't really need it any warmer than around 18 degrees.

 

[Thirsty Boy]

not sure about the temperature/ fire safety aspect, so I'll just say be careful....

But - yes, UV can be very bad for beer. UV light effects isomerised alpha acids (what you get in beer when you boil hops) and turns some of it into a mercaptan or thiol molecule - the same sort of molecules that give skunk spray its horrible smell, or that they put into natural gas so that you will realise you have left the stove on.

Some types of concentrated hops extract are chemically changed so that they don't react to UV light - they are the ones that Adamt is talking about, but not all hop extracts are UV proof and "real" hops certainly aren't. And unfortunately you have no way of knowing how your kit was hopped (apart from tasting the beer to see if its stinky) so its best to assume that it will be effected by light.

If you want to know the smell/taste we are talking about - buy yourself a bottle of Pure Blond (it skunks particularly well), pour half into a glass and sit it on your kitchen bench under a tea towel, pour the other half into a glass and sit it in bright direct sunlight. Wait 30mins. Smell and taste the beer from under the tea towel to give you a reference, then try the beer from in the sun. I bet you notice it before the glass even gets to your nose.

For your fermentor - put a couple of black t'shirts over it to keep the light out and to absorb the heat

Dont burn you house down

Cheers

TB

 

[buttersd70]

I bet you notice it before the glass even gets to your nose.

having tried something similar when I was new to brewing, the best advice I can give is to have a bucket handy for the inevitable results. :icon_vomit:
A fully skunked beer is not something you'll forget in a hurry :lol:

 

[datman510]

hey guys thanks for the info, the burning down the house thing isnt an issue (as i have insurance) nah its not a problem its not getting anywhere near that hot. everyone here keeps saying 18 degrees i was told 22 by my LHBS. should i drop it down to 18?

 

[buttersd70]

It depends on what yeast you're using, what style of beer you are brewing, and what characteristics you want from the yeast.