No chill, but no cube

[d2ww]

Hi all,
After a few years of doing kit beers, I've borrowed a Peco boiler and plan to do my first BIAB no chill brew. Trouble is unlike the Australians  on Youtube I don't have a cube to store the hot wort in. Instead, I plan to simply put the lid on at the end of the boil, place a cup over small hole where the thermometer goes, and leave overnight for it to cool, pitching the next day.
Am I inviting trouble with bacteria etc? or should I be ok?
I will be subtracting 20 mins for my hops additions to take into account not chilling the wort.

ps. Mods, when I requested another image for verification, it deletes the post!

[Ryan]

if the lid seals it shouldn't be much of an issue other than the clean up next day once you transfer.   the thermo plug should be better sealed than a loose cup tho. 

[TheSumOfAllBeers]

I used to do this, and got away with it while the house temp was cold, but had infections take hold when temperatures rose.

The cooling liquid and headspace contracts and sucks in air.

Cubes are cheap and versatile.

[LordEoin]

20 liter cubes only cost around €7 from the co-op

[Water_Wolf]

Are you planning on fermenting in the peco boiler? If not, you could transfer to your fermenter directly after the boil, seal that and then put the fermenter in a cold water bath to cool it quicker. I used to do this before I got the wort chiller.

Also, if you make a yeast starter that will reduce the chance of infection as the yeast can get a head start on some of the other organisms.

[d2ww]

Thanks for the replies, I didn't know that you could get cubes here so easily, and the yeast starter sounds like a good idea. This first time was a really good learning experience. Things like doing the mash and cooking dinner at the same time don't work too well together  I was a bit surprised by how much the temp dropped when I added the grains from 70 to 60 degrees, then again I only had 15 litres in the boiler as I didn't know how full it would get with grains added. Is there anything wrong with putting the grains in the oven at say 40 degrees while heating up your strike water?
Anyway, the fermenter is bubbling away nicely, so should know if it's worth all the fuss over and above a simple kit beer in due course.

[irish_goat]

If you put the grains in the oven at 40c the enzymes will start to kick in and you'll go through an acid rest. This may or may not be a good thing depending on your recipe.

You'll get to know your system overtime though, I add my grains to water at 72c and that always gives me 67c in the mash tun then.