Adding sugar to the secondary/lagering phase to form a CO2 blanket - necessary?

[AaronH]

Hi folks,

Looking to seek some advice on something. I'm brewing an all-grain Munich helles at the moment and am just about to siphon into the secondary vessel.

The batch is 19L and my secondary is a 25L fermentation bucket. I'm nervous that not enough of a CO2 blanket will form during the secondary, due to their being such a large (7+ litres, realistically) air gap above the beer.

I'm wondering if it would be smart to add a small amount of fermentables (probably just some bog-standard dextrose) to the secondary in order to kickstart some yeast action and generate some CO2?

This will be my combined lagering/dry-hopping phase as well and will probably last about two weeks. Do you think it's necessary to add sugar, or will there likely be enough dissolved CO2 in 18L to form enough of a blanket?

Thanks a million for any advice.

[Metattron]

Should be fine. Usually do 20l or so in 33l buckets for primary and secondary. No problems yet. Never added any secondary fermentables.

[Tom]

AFAIK you're advised to rack at the 3/4 stage (so with still a few gravity points to go). Most of the yeast will have dropped out by then, but there's still enough activity to produce a good blanket.

I've messed up two lagers to date by not having sufficient CO2 blanket over my beer, not to mention countless ciders. It's OK to be a little concerned, I think. But rack a little earlier, rather than adding fermentables.

[Eoin]

I've messed up two lagers to date by not having sufficient CO2 blanket over my beer, not to mention countless ciders. It's OK to be a little concerned, I think. But rack a little earlier, rather than adding fermentables.

How exactly "messed up", the co2 "blanket" idea is probably not the reason.

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[Tom]

It was the reason. It's the white flowery stuff that grows and laces the top of the beer in the fermenter if air has been allowed to get it. It's not acetobacter, lactobacillus or any of that shite.

[Eoin]

If it's a regular occurance I'd look elsewhere to be honest.

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[Tom]

It's not a regular occurrence, it happens when I let air get into the top of the fermenter.
I've clearly given the impression I know f-all about brewing. It's not the case.

[Eoin]

Air does not cause infection bacteria does. So ingress of air is not an issue.
Reference Pasteurs swan neck experiment. Less headspace and a high CO2 concentration can help to discourage the growth of aerobic bacteria if it gets in there but don't muddy the waters.

It's also best not to get defensive when discussing stuff otherwise it's a fight and not a discussion. I never thought you know nothing about brewing or said as much.

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[AaronH]

Thanks guys. I racked a week ago and was amazed at how quickly the CO2 blanket formed. The lid on the bucket has a nice upward bulge in it so I don't think I have anything to worry about.

Tom - I did notice some white "stuff" floating at the top of the beer when I cracked the primary, but I think it was just krausen that came loose. It didn't look much different than the krausen and everything smelled/looked great besides.

Will be removing the dry hopping bag and bottling tomorrow. Going to continue the lagering process in the bottle by using cold storage.

[Tom]

Air does not cause infection bacteria does. So ingress of air is not an issue.

Fair point.

[beerfly]

the act of transfering the beer will knock loose some co2 thats still in suspension too