too much head space in maturing vessel - minimise damage how?

[amorphia]

Hi there!

We (thought we) had enough fermented cider that it was going to easily fill a 25 litre demijohn when we siphoned it off the lees. However, we hadn't calculated that the lees themselves were taking up a lot of volume, nor that siphoning the last couple of litres was going to be really tricky (we gave up in the end because we had stirred up so much of the lees just trying to siphon it off).

So we ended up with about 2 or 3 litres of head space

So far the only ingredients in this brew have been apple juice we pressed ourselves from tree in our area, so we weren't eager to top it up with bought juice.

In the end we figured that perhaps if we added some sugar, then the small numbers of yeast that are still in suspension would fement it to fill the headspace with CO2. I've studied enough chemistry to work out that it would only need 3 teaspoons if all the sugar fermented. So we tried that

Almost 24 hours later, the pressure has if anything reduced in the head space. I guess there just wasn't enough yeast left or we didn't add enough sugar.

Is the damage already done, or is it not too late to add liquid instead? I could just add more sugar water. But how much damage will oxidation from 2 or 3 litres of air really do, compared to watering down like this?

If I had some big glass marbles I would gladly add them but I don't know where I'm going to get that many litres of them!

Thanks a lot for any comments!

Ben

 

[CvilleKevin]

I blow C02 into the head space so that there is no risk from oxidation.

If you dont have a CO2 tank, you can get a can of CO2 at most wine stores, sold as wine conditioner. Or you can use a CO2 keg charger with a pipe nipple on it. (see the middle of this page for a picture).

https://www.homebrewtalk.com/f32/results-juice-yeast-sugar-experiments-83060/index15.html

 

[amorphia]

Thanks a lot for the tip! I went to the brew shop and they had small cannisters of CO2 but no way to dispense it except quite expensive soda machines. I didn't feel confident about making something myself to crack open the cannister - messing about with very cold pressurised gas feels a bit dangerous if I don't know what I'm doing.

I have considered lowering a burning candle into the space but I figure smoked cider might not be what I'm after either!

The guy at the brew shop seemed to reckon that 2 or 3 litres of headspace for a cider mauturing for a month or two was no big deal... Be interesting to hear what anything else thinks of that claim.

Cheers,

Ben

 

[gratus fermentatio]

You might try dry ice, it's just solid CO2. Put a small chunk of dry ice into a sports bottle that has a drinking nozzle, add a cup of very warm tap water, put a hose on the drinking nozzle to direct the flow of fog (CO2 gas) into the carbouy. CO2 is heavier than air and will naturally sink & displace the air, blanketing the surface of the cider. In the US dry ice is available at some grocery stores & is pretty cheap. BTW, it's NOT a good idea to just drop a chunk into the carbouy. Hope that helps.
Regards, GF.

EDIT: Just be sure to wear gloves when handling dry ice. GF.

 

[CvilleKevin]

I just used a portable CO2 charger, which is fairly cheap, and put a 4" pipe nipple on it. Here's a link to the charger, I'm sure someone must sell them in UK

http://www.homebrewit.com/aisle/p/4990

Make sure you use beverage gas for refills and not paintball cartridges. Also the trigger is a little sensitive, since its not really made for this job.

The brew shop guy is right that a few liters of air is not a huge deal. I made ciders for years without using this. However, for the most part I've stopped using preservatives or chemicals/additives of any kind and I've found that minimizing air exposure significantly extends the life of the cider. If you want it to last a year or more, CO2 is the best head space filler IMHO. OTOH, if you are going to drink this within a few months, as is often the case, you dont need to control so much for air exposure

 

[Calder]

RDWHAHB

Quit worrying. Out-gassing of the cider will have provided a blanket of CO2 for protection. You added a small amount of sugar (which I regularly do when I transfer) which will have fermented and provided protection; there is plenty of yeast in suspension.

The best thing you can do is leave it alone.

 

[CvilleKevin]

+1 on RDWHAHB, but I dont believe OP can count on CO2 from ougassing

Adding sugar can work to create C02 if there are enough yeast and nutrient in suspension to quickly ferment the sugar. That is not always the case, depends on juice, yeast and process. A tablespoon of sugar should be plenty for a small burst of airlock activity assuming all the seals are good. Sounds like in this case, if there are any yeast, they are not active.

It is possible to knock the yeast out just by racking if you use fresh juice that is low in nitrogen (often the case with unfertilized or organic fertilized trees) and a yeast that uses a lot of nitrogen and flocculates well (many ale and wheat yeasts). Once the nitrogen is gone from the juice, the only place the yeast can get nitrogen is the dead yeast cells in the trub. Remove the trub and you have created a stuck fermentation.

I routinely do this on purpose so I can stop the cider with residual sugar (using cold crashing to accelerate the process). Seems like it might have happened here if there was no airlock activity from a tablespoon of sugar.

 

[amorphia]

Thanks for all the extra advice folks! Nice to hear from loads of people who sound like they know what they are talking about.

I reckon I'm just going to drink most of it soon, so it shouldn't be a problem even though there may not be a C02 blanket. I'll bottle some for some longer term storage, to see how further maturation affects it. I've got another batch in the fermentation bucket that needs to get in the demijohn!

Cheers,

Ben