Fermenting in the dark?

[Glen Gilchrist]

So, red tea bag wine brewing away....

Just had a "moment" - does it need to be kept in the dark to ferment? Or is constant temperature more important?

Cheers
Glen

[red]

you can lose colour if you keep it in the light.. matters for some things like erm.. blackberry

[Glen Gilchrist]

Thanks Red

Just colour - keeping it light won't promote nasties growing?

Cheers
Glen

[red]

well hmm. ideally it should be clean of all bugs etc apart from the yeast you added - which is why some recipes call for the ingredients to be boiled first. others dont though, and depend on the yeast population overwhelming anything else. i think i would prolly keep it out of the sunlight. cos you would get a change in heat and maybe that would effect it? otherwise i dont believe it has to be done in the dark.

[MKG]

The yeast doesn't care whether it's in the dark or not. However, it easier for you to see what's going on if you keep it in a reasonable light. Strong sunlight, as Red said, can destroy some wine pigments, but certainly not in the relatively short fermentation period. Basically, make it in the light and store it in the dark should cover most eventualities.

Large temperature variations, over time, will make the wine deteriorate. But that's for a time period of over a year. Small variations make very little difference.

Very little of my wine gets to any appreciable age, so I don't see any of these problems

Mike

[Zech]

I've been making (white) wine in the conservatory, for the sake of the heat, so I'm glad to hear the light doesn't encourage bugs or anything. It does affect the balloons I've been using as airlocks, though. I've just bought some rubber bungs and proper airlocks so I can use my freecycled demijohns, but it occurs to me that the bungs are rubber too, so probably also vulnerable to UV damage. Should I protect them?

[red]

i dont know about light damage to rubber bungs - but give them a good boil first.. or they can impart a nasty flavour to the wine

[MKG]

Yep - definitely never use a dirty bung. I replace my bungs at regular intervals (why does that sound vaguely obscene? ) so I don't think I'd ever reach the stage of UV damage.

Mike

[gregorach]

Beer is less tolerant - some of the hop compounds are photo-sensitive, so beer should be kept well away from bright light at all stages, and bottled in brown bottles. And I'm rather of the opinion that fermentation temperature should be kept as constant as possible (with certain specific exceptions), but again, that's probably something where beer is rather more finicky than wine... I go to fairly extreme lengths to accurately control my beer fermentation temperatures. Wine just gets left to get on with it.

[Zech]

Fermenting bucket in the conservatory not such a good idea for beer, then?

Hmmm......

[gregorach]

Fermenting bucket in the conservatory not such a good idea for beer, then?

Hmmm......

Certainly not ideal... I'd wrap it in something to protect it from both the light and temperature fluctuations. Definitely protect it from the light - the compounds produced by the photodegradation of hop acids are very similar to some of the components of skunk musk, and are noticeable at very low levels.

Actually, I'd move it somewhere else entirely... Certainly wouldn't leave it there come summer - fermenting beer can easily reach several degrees centigrade above the ambient temperature, so in a warm conservatory, it's almost certainly going to get warm enough to start producing strange flavours, and could conceivably get hot enough to actually kill the yeast.

(I should perhaps warn you that I have a fairly sophisticated programmable temperature control system that can regulate my fermentation temperature to better than +/- 0.1 degree C... Just so you know where I'm coming from. )

[Zech]

Certainly not ideal... I'd wrap it in something to protect it from both the light and temperature fluctuations. Definitely protect it from the light - the compounds produced by the photodegradation of hop acids are very similar to some of the components of skunk musk, and are noticeable at very low levels.

Well, it seems to have survived the best part of two weeks in the conservatory without developing overtones of skunk (surely even I'd notice ) It's now in bottles (clear ones ) in the kitchen, but will shortly be moved to the cool, dark store room.

Actually, I'd move it somewhere else entirely... Certainly wouldn't leave it there come summer - fermenting beer can easily reach several degrees centigrade above the ambient temperature, so in a warm conservatory, it's almost certainly going to get warm enough to start producing strange flavours, and could conceivably get hot enough to actually kill the yeast.

(I should perhaps warn you that I have a fairly sophisticated programmable temperature control system that can regulate my fermentation temperature to better than +/- 0.1 degree C... Just so you know where I'm coming from. )

My temperature control system goes something like this:

Winter : too cold to ferment anything here - best leave it a bit.
Spring : probably warm enough in the conservatory to wake the yeast up - try putting things in there
Summer : dunno yet, maybe try the kitchen, or wherever else I can find space.

Thanks for the advice, though. It's nice to know what I should be doing, even if I can't be bothered! More to the point, it's good to know the potential consequences of taking shortcuts.

[gregorach]

With ale yeast, you're fairly unlikely to actually kill it - it can handle temperatures of up to 37 degrees C (if I recall). It will produce lots more esters (a range of flavours, including fruity and solvent) and higher alcohols (which give you a bad hangover) at warm temperatures. Lager yeast is much less able to cope with high temperatures and will start dying once you get much over 30. Mind you, a lager fermented anywhere near that warm would taste absolutely manky anyway...

It surprising how many people don't notice weird flavours in their beers though. Beck's is the canonical example of a "skunked" or "light-struck" beer, and it sells just fine... Not sure if it leaves the brewery like that, and I haven't actually drunk the stuff in years, but you ask most brewers what a "skunked" beer tastes like, and they'll answer "Beck's". Start collecting proper brown beer bottles!

[Glen Gilchrist]

Hi all

Amazing how an innocent question leads to all this ;-)

Having literally just started I have yet to consider "beer" as a project, but will certainly keep mine in the dark when I get going.

What about Cider? I have x1 gallon of apple juice on the go at the moment....

Cheers
Glen