sun while fermentation?

[bogbog]

hello,

I actually have a bottle of sugar and prunes fermenting with yeast I cultivated myself from prunes.
It's the first time I try to make alcohol and I'm asking myself where to store my bottle while fermentation. I only found informations about temperature influence, but what about the sun? Is it better to put the bottle in the dark or near a window?

thanks

 

[chawn]

I don't know anything about fermenting prunes, but light produces off-flavors in beer. I'd keep it in the dark.

 

[Homercidal]

I know that certain wavelengths of light can have a negative effect on hop compounds after isomerization.

I have no idea how sunlight affects a fruit wine (or PRUNO, in this case.)

 

[giraffe]

Without hops it should be fine in the light, but maybe not. A dark shirt or towel wrapped around the bottle will solve the problem though, so id do that for safety. There is no positive reason to put it in the light.

 

[katmeefer]

I agree with giraffe.
I once fermented some mead in the summer sunlight outside and it turned out supurb. But that could be because i was fermenting champagne yeast which needs a high temperature to ferment properly.
I would research the light sensitivity of the specific yeast strain youre using but in my experience temperature is far more important than light.

 

[Malted_hops]

What I've heard is that direct sunlight can harm the yeast. The UV radiation in sunlight can cause genetic mutations in them. It shouldn't be a problem in a single batch. But if you start harvesting yeast for later use, after several generations the yeast won't be the same as you started with. Maybe it's a good change, maybe it's a bad change, but they will change.

 

[Kahless]

Sunlight reacts negatively with red wine, so it may do a similar thing with prunes.

Fermentation is exothermic, so once it starts going you can wrap it in a jumper and it will generate some of its own heat, for at least the first 5 days. I'd recommend getting a thermometer, but as it is a wild yeast you might need to experiment to see which temperatures are best. A lot of yeasts work well at just above 20C, and can produce off flavours above 24C (would end up very hot-alcohol tasting), so that might be a good place to start.