Newbie query

[GaSh65]

Hi folks, hope you're all keeping well?
I started brewing beginning of the year. I've been buying the basic ingredients kits from Wilko. Just started my sixth batch, which is my second Stout. I'm at the 'sick of bottling' stage, so have just bought my second King Keg.
However, I only realised before the current batch, that I'm supposed to put liquid in the airlock on the FV. I usually just stick the airlock in the top and leave the cap on.
Every batch so far, mostly bottled and one keg of Stout, have come out fine.
I've added some diluted StarSan to the airlock for the current batch, which has been 'glooping' nicely.
So my question is, does it do the beer any real harm to not put liquid in and therefore I've so far been lucky?
Thanks in advance.
Gary

 

[cushyno]

Without liquid in the airlock it's possible for airborne bacteria to get into the beer. However, while the beer is fermenting the positive pressure of that co2 being produced will mostly be pushing out any air and filling your head space (gap above the wort) with co2. Only once fermentation has ended may air really be sucked back in if temperature becomes cooler.

You'd have to be unlucky to get a spoiled batch.

The other factor is oxygen. If the beer is exposed to oxygen then it begins to spoil. So long as you have kegged/bottled your beer not long after fermentation has finished then you probably won't notice any detrimental oxidation spoiling.

In future, put starsan/chemsan or a quarter of a campden tablet in water into your airlock and leave off the cap.

Some people don't bother with airlocks and rely on positive pressure or a layer of krausen to protect their wort, such as breweries that brew in open vats or "Yorkshire squares".

 

[Chippy_Tea]

To avoid this you could use a blow off tube

https://www.thehomebrewforum.co.uk/threads/how-to-make-a-blow-off-tube.48970/

 

[GaSh65]

Thanks to both of you for your suggestions. I've since followed the instructions on the link above and made a blow off tube, using an old litre glass bottle. I've poured into it a diluted 2:1 thin bleach, used the tube from my siphon, cut the end from an airlock and held the tube in the bottle with a chunk of BluTac.
However, I'm now 2.5 days into fermentation, there are signs of reaction at the top of the FV, it definitely has a Krausen but I've had zero foam or seen evidence of gas moving along the tube and into the bottle.
This could be due to the following: whilst cutting open the kit sachet of yeast, I cut into my finger and due to the jolt of pain (strangely it didn't bleed) I dropped the sachet on the floor. A small portion of the contents spilt out, which I discarded as I didn't want any dirt or other matter to mix with the yeast. I then poured the remainder of the sachet into the FV.
So, could my assumption be correct? Is there going to be a problem with a smaller amount of yeast, that will cause the batch to be no good? Or will the fermentation just take longer?
All or any help with this will be greatly appreciated.

 

[Chippy_Tea]

Don't worry about a small amount of yeast you lost itll be fine.

 

[GaSh65]

Don't worry about a small amount of yeast you lost itll be fine.

Brilliant! Thanks so much for that.
So the lack of foam/gas isn't a worry either? Or could it just be a bit later than usual?

 

[Chippy_Tea]

A lot of FV's are not 100% airtight so the CO2 may be finding an easier way out and as there isn't much produced in early fermentation you wont see activity in the blow off tube container, try lowering the amount of water in the container until its barely covering the end of the tube and make sure there is a gap in the blu-tac to let CO2 out.

 

[DocAnna]

The primary function of an airlock/bubbler is as a dust and flying beastie filter. The volume of air that it can prevent change of is tiny, so significant contraction of the headspace in later part of the fermentation due to temperature changes will easily suck air back through the airlock. Bacteria can't fly or jump so simply covering the area will prevent most getting in, as you have likely discovered. Bacteria are present on dust particles and tiny flies (flying wee beasties) which on the other hand will go through an airlock if it doesn't haven't anything in it. Keeping the temperature stable is another part of preventing air getting in as if fermenting at room temperature, the headspace gas will contract when the temperature falls at night and suck back air.

To be fair the airlock does reduce oxygen diffusion into the headspace, but this is more of an issue towards the end of fermentation when the positive flow of CO2 from fermentation is reduced.

Anna

 

[An Ankoù]

Hi @GaSh65, as pointed out above, the chances of getting an airborne infection through an empty airlock are negligible. You've got more chance of sucking contaminated liquid back into the FV. These things were designed for 1-gallon demijohns, really, not 5+ gallon vessels with big floppy lids. I started filling my airlocks with 40% abv spirit for fruits (a bit stronger and much cheaper than vodka) and then gave up liquids and wrapped the airlock with a small size freezer / lunch bag. Now I just put a bit of kitchen roll in the bung hole. The whole lot's covered with a dark cloth anyway to prevent light damage. Unless the airlock is designed for the fermenter, eg. Speidel, they're best left for the wine-makers IMO.