Fermentation in direct sunlight

[Zamial]

Hello HBT, I have returned with a homebrewing question/concerns and would like some input from the mob! Google gives me little info on the subject.

I am planning to brew a 6 gallon batch of ale. I will be camping and taking the beer from grain to glass in 5 days. This is also to be a live brewing demo. I will use DME and honey to make a wheat style braggot. I will NOT be adding any hops to the boil. The boil will only be for 15 minutes as there will be no steeping grains. (I do not care about head retention I care about wasting time on my vacation!)

As part of the demo I would like to primary ferment in a glass carboy on a stand that will be in direct sunlight/outdoors I want folks to come up and see it fermenting!

Once the ale reaches the correct gravity I will rack it (still fermenting) into a pin (cask) and seal it to naturally carb it to the desired vol. At this time I will add Iso Alpha hop extract to about 20 IBU and about 3 oz of centennial hops.

I understand that this:
1. May not work.
2. May not be the best tasting ale ever made. (It just needs to be drinkable.)

Is there anything I am overlooking that the sunlight would mess up or off flavors from the sunlight? As there will be no hops in the wort for the sunlight to light strike...

I am not really worried about temp control at all or flavors associated with that. I am mostly worried I am forgetting something that the sunlight will alter he fermentation in a bad way.

Thanks!

 

[Yooper]

Hi Sam! Long time, no "see" here on the forum. Hope you and the family are well.

First, I need to say that I really have no idea about this- but that never stopped me before!

While hops in the wort would definitely "skunk" in the presence of sunlight, as a long-time winemaker and aficianado, light damages wine (and cider and mead) as well, and there are no hops in there. Light will "bleach" out a red wine, and change the flavor, and white wines as well as ciders will get light struck.

My gut tells me that while the beer won't get skunked from the light (due to no hops), it will get light struck. Perhaps a simple tarp covering the area will protect it from the elements as well as the bulk of the sun exposure? And maybe help keep the fermentation temperature stable as well since it wouldn't go from sun/dark, sun/dark for those days?

 

[Zamial]

Thanks Yooper! It has been a long while since I had a homebrew question! The fam is doing well. Hope you and yours are as well!

If I do not get a "for sure answer" (not that your reply isn't) I may just have to do a pilot batch and see what happens... The fermentation will be for just over 3 days "exposed" in sunlight depending on weather will depend on teh severity of exposure and there will be some shade...

 

[mongoose33]

Perhaps just covering it with a tarp that can be lifted for people to see active fermentation, then cover it up again. There could be some mystery involved given that "something" is going on under there even when they aren't looking.

When I ferment in my basement I cover the fermenters with a large cardboard box to prevent any light reaching them. I'd think, if you're introducing people to brewing, you'd want the result to taste good.

Another idea: have two fermenters, one they can watch, one that is protected and which will be drunk. May not fit your "vacation" approach.

 

[GPP33]

I have absolutely no idea if this will be drinkable but I'm super interested in seeing how it turns out. Is the only reason you aren't adding hops to limit UV damage?