Fruit fly problem

[BarryW]

I am a novice brewer of cider, having made my first batch a couple of years ago with moderate success. This year, I am trying again! I have 35 litres of hard cider coming to the end of a first fermentation period. I have a problem with fruit flies, some of which have got into my fermentation tubs. Will this ruin my finished product? Do I skim them off the top immediately or is it too late? Having googled the problem, the conclusion seems to be that they are harmless but I'm not convinced.
Thanks

 

[Jim Brewster]

They like my beer too. I think they're fairly harmless as they're mostly attracted to fermenting fruit anyway, but there is always a risk of infection. If they're removed or if it's racked before they start to decompose I think it'll be mostly OK

 

[Sadfield]

Make a trap with vinegar or some of your fermenting cider, with a small drop of washing up liquid in it. The washing up liquid lowers the surface tension preventing them from flying down, feeding and then flying away.

 

[Druncan]

I use 12w 240v zappers in the brewery. INDUSTRIAL 40W 20W 12W ELECTRICAL INSECT BUG FLY MOSQUITO KILLER ZAPPER 2UV TUBE | eBay. Prices have risen slightly recently, but they work brilliantly.

Any extra flies that get in through the door get sprayed with SS or PAA. (It's a great test for spray activity. If it drops them then it's good,,,,

as I spin the spray bottle around my finger like a gunslinger Feel lucky punk?,,,,,,,,

 

[Sadfield]

Brutal, but thorough.

 

[Bernie]

They are your friends as they carry yeast into the ferment.

 

[Druncan]

Eeeeeeek

They are your friends as they carry yeast into the ferment.

Not friends I plan to introduce to my brews. They live in rotting fruit and coo/sheep poo up here!

I have had minor wild yeast and bacterial infection that I suspect was due to this in the past. Spoilage infections are not nice or cost effective. Insect screens and my due diligence are the friends my EHO likes.

Zap em all,,,,,

 

[phildo79]

Stop leaving bananas out. Put potatoes in the fridge. Buy a bug zapper. But the most effective way of getting rid of them is a cup of vinegar with clingfilm over the opening. Pierce a small hole in the middle. They get in ok but struggle to get out. After a few days, it's like a flies graveyard in there.

 

[JaggersBrewingCo]

I like the idea of the traps that where mentioned, we have employed this method before.

I had them get into some Kombucha when an air lock ran dry, I didn't want to risk it and throw the batch out, and Scoby went to the chickens. After having a batch of Fruited Berliner Weisse turn to Vinegar I do not play around with flys.

 

[Alfie_The_Cat]

Stop leaving bananas out. Put potatoes in the fridge. Buy a bug zapper. But the most effective way of getting rid of them is a cup of vinegar with clingfilm over the opening. Pierce a small hole in the middle. They get in ok but struggle to get out. After a few days, it's like a flies graveyard in there.

I'll be making a vinegar trap when I get home now

 

[Ale House Rock]

What Sadfield said. Don't forget the small amount of washing up liquid.

 

[phildo79]

I have found I didn't need the washing up liquid. Just ordinary malt vinegar. I've heard the washing up liquid being used with a cup of red wine though.

 

[YeastFace]

Haven't seen any for a couple of weeks, but a few of the fuckers have appeared today. Thanks for the tips on the trap. Have caught one so far.

 

[BarryW]

Some great advice here.....thankyou. I have already put sticky fly traps around the area and have caught lots of 'em. I also use a fly spray on a regular basis. I will try the bowl of vinegar and washing up liquid as well. It's good to know that the little blighters haven't ruined my cider. Thanks again.

 

[Haversham]

I've seen a few fruit flies recently but compared to the numbers we had when we lived abroad, the population doesn't seem high enough to bother with traps where I am. But FYI, what we used to do (similar to what's been said already) was to use cheap champagne flutes (or other long, narrow glasses) put an inch of red wine in the bottom, seal the top with cling film and make 4 or 5 small holes with the tip of a sharp knife. Alternatively, get some empty screw top jars and punch a few holes in the lid with a skewer or similar. Again, red wine or vinegar and a small bit of fruit -- banana or apple -- in the base. We caught hundreds of the buggers each summer this way.

 

[Wobbly13]

Experienced a lot up here in Scotland this year. Our local pub is inundated. I purchased a couple of these and they cited the problem in our house. Will now clean out every 3 weeks and refill with cider vinegar, sugar and washing up liquid mix. Key seems to be keeping the yellow funnel bit clean and dry so the suckers end up on the liquid.

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