Down the sink

Get advice on making beer from raw ingredients (malt, hops, water and yeast)
Graham

Re: Down the sink

Post by Graham » Sun Sep 30, 2007 1:43 pm

Garth wrote:
I believe the cause was those small flies, bit of a brown round body and tiny wings, I'd seen a few around the fv last week and thought I'd got rid of them.
Almost certainly. They are frit flies (not fruit flies), and they live on barley. In September when a combine harvester is thrashing around in a field nearby, they swarm and can be a pain; they carry all sorts of barley-loving, beer-spoiling bacteria. They are attracted to the smell of beer, and commit suicide by diving into it.

I used to be plagued by the bloody things.

A bit of old (but clean) net curtain material has been successful at keeping them out of open fermentors.

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johnmac
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Post by johnmac » Sun Sep 30, 2007 5:02 pm

Almost certainly. They are frit flies (not fruit flies), and they live on barley. In September when a combine harvester is thrashing around in a field nearby, they swarm and can be a pain; they carry all sorts of barley-loving, beer-spoiling bacteria. They are attracted to the smell of beer, and commit suicide by diving into it.
When I worked in a pub, I was told "don't leave a cask without a spile, or you'll get beer flies in it" So now I know what he meant by "beer flies"!

prolix

Post by prolix » Sun Sep 30, 2007 11:51 pm

G the are a git to get rid of any beer spillages will spawn hundreds of the buggers. I lost a batch to them a couple of weeks ago
People who make wine, cider or beer should ensure that the containers are well sealed; otherwise, fruit flies will lay their eggs under the lid and the tiny larvae will enter the container upon hatching. Upon emerging, the tiny larvae feed near the surface of the fermenting mass. The reproductive potential of fruit flies is enormous; given the opportunity, they will lay about 500 eggs. The entire lifecycle from egg to adult can be completed in about a week.

Graham

Post by Graham » Mon Oct 01, 2007 2:56 am

prolix wrote:G the are a git to get rid of any beer spillages will spawn hundreds of the buggers. I lost a batch to them a couple of weeks ago
People who make wine, cider or beer should ensure that the containers are well sealed; otherwise, fruit flies will lay their eggs under the lid and the tiny larvae will enter the container upon hatching. Upon emerging, the tiny larvae feed near the surface of the fermenting mass. The reproductive potential of fruit flies is enormous; given the opportunity, they will lay about 500 eggs. The entire lifecycle from egg to adult can be completed in about a week.
Yes, they could quite easily be fruit flies of course. I tried to identify the little beggars that used to pester me (courtesy of my Collins guide to insects) and came to the conclusion that they were frit flies mostly due to their size and that they only bothered me at harvest time. Frit flies are very small, smaller than fruit flies. However there are dozens of different flies in the frit / fruit fly sort of thing; all have their own unique hosts, and it is difficult to identify something for certain that is only a couple of millimeters in length.

No matter what they are, you really don't want them, of course. If they are frit flies you won't get problems with egg-laying and reproduction, the lava needs barley or oats to munch on from what I can work out, but from what I have just read on the interweb fruit flies are a totally different issue. It seems that they can breed anywhere there is decaying matter; even in drains and dustbins. That's worrying; difficult to get rid of the buggers if they are breeding in someones drain, or on fallen fruit, three doors up the street.

I believe that these little critters are responsible for more infected beer than is commonly realised. If one gets into your beer, infection is inevitable. It makes me wonder how commercial brewers coped with the problem, apart from not brewing in the summer.

Graham

Post by Graham » Mon Oct 01, 2007 3:23 am

Found this on the interweb while looking up fruit flies:

One day an Englishman, a Scotsman, and an Irishman walked into a pub together.

They each bought a pint of Guinness. Just as they were about to enjoy their creamy beverage, three flies landed in each of their pints, and were stuck in the thick head.

The Englishman pushed his beer away in disgust.

The Scotsman fished the fly out of his beer, and continued drinking it, as if nothing had happened.

The Irishman, too, picked the fly out of his drink, held it out over the beer, and started yelling, "SPIT IT OUT, SPIT IT OUT YOU B****RD!!!!

oblivious

Post by oblivious » Mon Oct 01, 2007 9:16 am

David Edge wrote:
on a connected note, has anyone thought of buying a one of those cheap fly electrocution things, to have around where you ferment, I've seen them in several breweries,
I seem to recall reading - probably in New Scientist - that the problem is that they propel bacteria-laden lumps of fly all over the place. If you did use one it would be wise to keep the fermenter out of the line of fire.
What about a couple of Venus Flytraps then? :wink:

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