Headspace when racking to secondary (oxidation)

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damdaman

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Hey everyone... I have my first mead that has been fermenting for 3 weeks now. It is progressing well, OG was 1.100 and SG today was 1.015. I made a 2.5 gallon batch and put it into a 3 gallon carboy, since this is my first mead I didn't want to invest in a 5gal batch in case I screwed it up. (I had a previous thread worrying unnecessarily about a slow start to fermentation here (recipe included): https://www.homebrewtalk.com/f30/apparent-slow-start-my-first-mead-159234/)

My plan was to wait until primary fermentation was complete and then rack it to a temporary vessel, clean out the 3gal carboy, sanitize it, and then rack it back into the carboy for secondary/clearing.

However now I'm concerned that since fermentation will be over and no more co2 is being produced, this will leave a lot of air in contact with the mead and thus possibly lead to oxidation.

Do you more experienced folks here think this is a threat, or am I being overly cautious? Is there a way to neutralize this threat, perhaps racking to secondary BEFORE fermentation is over (say at 1.010 SG) so that some co2 is created and pushes out the o2? Or do I need to find a smaller secondary vessel to eliminate the headspace?
 
you can do a couple of things.

1. add clean water to the carboy until it is about an inch below the stopper.

2. use a wine preservitive. they are basicly a can of inert gases that are heaver than air that keep o2 from off of the surface of the wine or mead.

dont rack your mead until at least 90% of fermintation is complete
 
you can do a couple of things.

1. add clean water to the carboy until it is about an inch below the stopper.

Your not going to want to add over half a gallon of water to a 2.5 gallon batch. It would dilute things too much.

I think your best option would be to find a couple of gallon jugs, use those as your secondaries, and save the leftovers for future rackings.
 
This is why I make a batch to ensure 5g in the secondary anymore. I used to primary in 5g..but when I racked, I had tons of headspace and actually have lost 2 batches to oxidation.

Or the alternative, is to make a spare 1g batch along side your batch, so you have something to top up with when you rack.

I was going to recommend adding some must (water + honey) to fill it back up, but since it's already semi-sweet at 1.015 - I'm not sure adding more honey would be a good idea, if the yeast is at it's tolerance.

Wait, I went back and saw you did champagne yeast...so theoretically, this could take more honey and continue fermenting. To be honest, at 1.015 -- I'm not sure this thing is done anyways...so you may end up seeing more fermentation post-racking. You could mix up a little honey and 1/2g of water and top up and hope this ferments out a little.
 
If it was my mead, I'd either top up by adding sanitized glass marbles (but you need aLOT of marbles for that much headspace), top up by adding must, or rack to two one gallon jugs. I have several Carlo Rossi wine jugs just for that purpose. A #6 stopper fits the one gallon jugs, and then I just use an airlock on each.

I always make a bit more than the "right" sized batch, and keep the extra in a wine bottle (with a small stopper- any homebrew store has them) to top up as there are always racking losses. I usually primary in a bucket, so that I can make a little more than fits in my carboy, too.

Mead is a long term commitment, and it's well worth it to protect it from oxidation in the secondary.
 
Thanks for the replies everyone, these are great ideas. Yes I'm quite sure it's not done fermenting yet, but I'm just planning ahead as I intend to rack to secondary in the next week or two, assuming all goes well.

I like the idea of two 1gal jugs. Maybe I can find a .5gal jug as well.

But the idea of topping off with more must is interesting as well. Would you recommend a dose of nutrient/energizer when doing this?
 
If it was my mead, I'd either top up by adding sanitized glass marbles (but you need aLOT of marbles for that much headspace), .

There's 2 big negatives to this idea. 1) as yoop says - you need a LOT of marbles, but 2 - when you go to rack off - there's a TON of mead in all that space between the marbles (they are round you know) - which means you lose even MORE mead...and the more marbles you use, the more mead you lose.


I've never bothered to top up with must, but my theory is that I wouldn't worry about it too much. I've heard there's some things to not nutrient after a certain point (some of the more technical chemical guys might have a good answer to that), so you may want to wait for another answer on that.

Personally, either top up with water (usually I don't have .5 or more of headspace, so the dilution is minimal) or prepare by having a bigger batch than I need, so I can rack to a smaller carboy and save any leftovers in a 1/2g growler under airlock in case I need some backup top-up.

Also, if you get another mead in progress, sometimes you can split the difference and use some fermented dry mead to top up a mead that's a little sweet and try to balance it out a little. (or the reverse..)
 
Damdaman, there are a lot of options you can use, but the common theme is that a lot of headspace in secondary (or thereafter) is bad. While many meads (especially traditionals) are much less susceptible to oxidation than are most wines and beers, having headspace oxygen allows spoilage organisms (especially acetic acid bacteria) to have a field day with your mead. So the key is to minimize oxygen exposure in storage containers.

You can do any of the following:

1. Top up - with water, other mead, or must. Each approach has cons. Water dilutes. To use other mead, you have to have some around. Adding must either means you have fermentation kick of again (with tired stressed yeast), or you'll be sweetening.

2. Add inert material to remove space - glass marbles, stainless steel bearings or any other inert material can be used. It can be impractical for large volumes and makes racking later more challenging.

3. Flush the space with inert gas - CO2 is less than ideal as it dissolves into the mead. Nitrogen or Argon are better. You have to flush all the oxygen out, so you have to use large amounts. The notion that you can just put a puff of Argon or CO2 in and it will settle like a blanket on the surface of the mead is urban myth.

4. Use smaller containers - this is often the easiest approach. I have gallon jugs, double magnum bottles, 3/4 gallon apple juice containers which may get used at times. A 2 liter PET Plastic bottle can be used (at least for a few months) and the airspace can be squeezed out.

5. Use a blanket of mineral oil - Old tradition sometimes said olive oil but vegetable oils can go rancid. Pharmacy grade mineral oil (used as a laxative) will keep air away, is safe if ingested, and won't go rancid. It is messy and I don't like to handle an oily 5-gallon glass carboy (that's like asking for an ER visit).

6. Use a balloon - I saw someone try a mylar balloon inflated in the headspace to eliminate air. I don't know if that is food grade, and I haven't yet seen a food-grade practical answer for home use, but they have a product for barrels like this.

As long as you use some method to keep air away from the mead, you'll keep spoilage organisms at bay, and may avoid oxidation especially of more-sensitive melomels.

Good mazing!

Medsen
 
So I picked up 5 64oz. growlers today and got airlocks for them. I'm going to use these to secondary.

Thanks for the all the suggestions!
 
It is really cheap to buy bungs that will fit an airlock onto a wine bottle or any sized beer bottle. Basically, I start up a small batch in my 2 gallon primary. I then rack to a 1 gallon jug, and anything left over goes into a 1/2 gallon jug, 1 L wine bottle, 750 mL: wine bottle, 22 oz beer bottle, or 12 oz beer bottle.

Downsides: it is hard to see the lees with brown glass, and I end up pouring out of the bottles rather than siphoning.
 
Ok, so I racked to secondaries today and I'm wondering what you guys all consider a safe amount of headspace. I filled up 5 64oz. growlers, but these growlers already have a little headspace above the 64oz. mark, plus with the must lost due to racking and hydrometer samples, I ended up with about 2" of headspace in each growler (mostly neck, but coming out a little bit to the flared part of the bottle). Is this too much?
 
Can't you just dose it with some potassium metabisulfite? Metabisulfites are used to prevent oxidation and spoilage in wine. Why not mead?
 
Sulfites are good for mead and I use them regularly, however, they will not protect a mead from acetic acid bacteria that has a supply of oxygen. Even 100 ppm free SO2 is not enough to stop them, especially if the pH is near 4.0 - the surest way to keep them suppressed is to allow them to have no oxygen.
 
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