Peculiar film on top of melomel (and trying to fix the haze)

[InfinityOnHigh]

I have a blackberry and black cherry melomel that I started brewing in back in early August. Recently during my checks I've noticed a thin, seemingly crystalline, iridescent film on the surface that is strong enough to pin some bubbles beneath it. I've been trying to identify it to make sure it's not a problem or hazard that needs to be solved, but have had unsatisfactory results. My first guess is that it's a sugar film, similar to that which forms on the top of a syrup as it cools. I didn't use a sugar syrup for this though, only honey - although I'd assume there must be other mechanisms by which it could form off sugars in the honey. Also, the films on syrup I've seen are not as iridescent. My second guess would be contamination from acetic acid bacteria, which is a stretch as it isn't glossy and oily, but rather solid and crinkly. Plus the the carboy has been sealed and the headspace filled with off gas since racking.

I've also been noticing a haze in the melomel. I figure that this is protein haze; I was sure to add pectolase, so I doubt this is pectic haze. It also stands to reason that this issue arose just from the honey. I made a lemony mead earlier this summer with the same type of honey and it has a similar haze - however, contrarily, I made a blackberry melomel also with the same type of honey, and it is as clear as (black) glass. Which leads me to my final doubt - this isn't a white whine, and in fact it nearly borders black (or at least a very dark magenta/violet) Are there good defining tests I can do to make sure it's protein haze or is it just visual cues and deduction? Also, is bentonite the best recourse if it is protein haze? I figure it would work similarly despite myself not working with grapes here.

Recipe wise for the melomel, I used 5 and 3/4 cups of blackberries and 5 and 2/3 cups of black cherries, pulped WITH seeds. I also used 2 cups clover honey, 5g of EC-1118, 1/2 tsp of pectolase, and water to 1 gallon. I racked it once off the lees and cherry seeds 2 weeks in. I feel like I've been very on top of preventing contamination, but you never know.

If you need anymore information let me know. Any help would be appreciated.

 

[sour_grapes]

Gosh, if it were my wine, I would quickly rack it out of that vessel into another, doing my best to leave the surface film behind. i would treat it with K-meta, top up, and hang on for a while to see if anything bad develops.

 

[Rice_Guy]

Do you have gravity readings? Gravity numbers give us an idea how competent the yeast are and if things are changing.

. . . Recipe wise for the melomel, I used 5 and 3/4 cups of blackberries and 5 and 2/3 cups of black cherries, pulped WITH seeds. I also used 2 cups clover honey, 5g of EC-1118, 1/2 tsp of pectolase, and water to 1 gallon. I racked it once off the lees and cherry seeds 2 weeks in. I feel like I've been very on top of preventing contamination,

* If you have a protein haze bentonite should pull it out. Honey has a lot of protein therefore it is a good guess. The way to eliminate that risk is to heat the honey and cause the protein to clump. Proteins will show up at the start, ie not develop after racking. Anyway a protein haze is cosmetic and won’t make a bad mead. Micro growth can make bad mead.
* I do not like the surface film. I doubt that a mead at 1.100 sugar density would be capable of crystallizing. This leaves the risk of microbial infection. If you wipe it with a Q tip will it flex? If you rub some of it between your fingers does it rub into nothing? feel greasy?
Your recipe doesn’t note any campden or metabisulphite. How much was used? Anyway the standard treatment for a surface film is to carefully remove it with paper towel, add 75 to 100 ppm metabisulphite (.3 to .4 gram per gallon or half a crushed Campden tablet) and carefully layer some alcohol on the neck.
A surface infection requires oxygen to grow. What is the head space? On a gallon carboy I would try for an inch/ 2 cm. An infection could also generate a haze on a formerly clear wine.
* Bing cherry and black berry are not high pectin. Pectic enzyme doesn’t hurt but doesn’t do a lot without pectin to work on.
* Many food processes are controlled by pH. A 0.1 accuracy costs about as much as your honey, pH paper is cheaper but doesn’t work n dark color fruit. I didn’t see added acid in your recipe. Food poisoning isn’t much risk below pH 4.0. (or once the alcohol is above 5% ABV). Bing cherry has a high pH in 4.5 to 5 range. (Did you harvest wild cherry?)
* Gravity? The drop in sugar gravity tracks the production of alcohol. At 18% there is little risk. At 15% ABV all but strong yeast like 1118 die off. A triple scale hydrometer is less than $10 and reads potential alcohol. Again once over 5% there is little food poisoning risk.
* What does the mead taste like? Much of your risk is off flavors, ,,, which won’t kill you.

 

[InfinityOnHigh]

If you have a protein haze bentonite should pull it out...

Can’t really use bentonite. It would require adding too much water to the point that I’d be diluting the wine too much. But the honey heating trick I may use in the future. Also the haze has started to clear up. I still don’t know what caused it or why it now is stopping, but my best guess is tartaric acid precipitation (two other wines I’m working on simultaneously started precipitating, probably brought on by low temperatures in my area; all so sudden and unpredictable and educational).

This leaves the risk of microbial infection...

At this point I don’t think the surface film is an infection. I pulled some up with a stick; it sort of crumbled like a soggy version of those thin clear chewing mint sheets. I sampled some (in hindsight, rubbing it with my fingers would probably have been a better first test) and it tasted like a gummier version of the wine itself. In pulling up the sample I broke up the film considerably, and since then have checked daily and noticed no growth or other surface blemishes (save the bits of film left behind). My only guess now is that it may have been some light proteins and sugars that bound together, but I really have no way to definitively know.

I’ve tried to stick away from chemical additives - more so as a fun exercise than anything else - but a different melomel I had got infected with some acetobacter. I’ve already used k meta to kill the infection, and since it and this melomel have run dry I’m doing k meta and k sorbate tonight to stabilize the wines for back sweetening.

Headspace is 7cm, but it tapers quickly to a thin neck. I don’t think enough oxygen could have gotten in to cause an infection - I’ve only ever taken the bung off to rack once and take a sample a couple days ago. My concern was mostly about maybe it was a toxic precipitate, however unlikely, as I had never seen something like it before.

Bing cherry and black berry are not high pectin...

I added 1/2 tsp of pectolase 24 hours before brewing. Forgot to add that.

I didn’t see added acid in your recipe...

I didn’t add acids because I figured the cherries and blackberries were acidic enough as they were; if it comes to a matter or taste I’ve always preferred to add some volume of lemon juice. pH paper is probably a good idea going forward, but a lot of the fruits I work with are rather dark. The cherries and blackberries were both wild.

Gravity? ...

I don’t have gravity readings. I got a hydrometer earlier this summer, but it’s too tall. I can’t actually set it into my carboy without it sinking to the bottom, mucking up the reading. I could draw some off into a tall tube, but I’ve feared that would require too much handling and increase contamination risk. I have a system of equations and constants that I’ve been using that worked out rather accurately (more or less). The initial brix should have been 16.05°Bx, or 1.0656 SG, meaning if it runs dry it should come out to about 11.9% ABV, well over 5%. I use EC1118, so I figure that shouldn’t be a problem.

What does the mead taste like? ...

The melomel tastes good. I haven’t drank too many wines/melomels/meads to know what to look for, but the taste is pleasant if but a little dry. There was notable acidity but I think it worked well with the flavor. I couldn’t taste any vinegary or off flavors, but it did taste a bit thin - I added 1/2 tsp of tannins, and stirred up some of the precipitates from the bottom. Don’t know if it’ll do anything, but it can’t hurt. Once I backsweeten it’ll probably taste a bit better, plus by then if the tannins would have done anything they can do.

 

[David Violante]

Do you happen to have any pictures? Was the honey strained or was there any wax possibly in it?

 

[Rice_Guy]

I don’t have gravity readings. I got a hydrometer earlier this summer, but it’s too tall. I can’t actually set it into my carboy without it sinking to the bottom, mucking up the reading. I could draw some off into a tall tube, but I’ve feared that would require too much handling and increase contamination risk. I have a system of equations and constants that I’ve been using that worked out rather accurately (more or less). The initial brix should have been 16.05°Bx, or 1.0656 SG, meaning if it runs dry it should come out to about 11.9% ABV, well over 5%. I use EC1118, so I figure that shouldn’t be a problem.
The melomel tastes good.

A 1.065 should get about 8% ABV. Honey is not reliable, the percentage sugar varies a lot from pail to pail. For very small low gravity samples I am using a skinny bud vase, for high gravity high floating must 40 cC in a 50 ml plastic cylinder is working.
Taste is everything, you were successful.
The fruit you put in does not have tartaric acid, that is not a choice. At 1.065 a honey will dissolve. Honey that has not dissolved will sink since its density is high.

 

[Ohio Bob]

I’ll add this for what it’s worth...
I had a Chilean Merlot juice bucket that might be similar. Fermentation was in an open bucket, when it got to SG 1.030 I added Acti-ML and VP41 MLB, transferred to an airlocked Fermnonster, then kind of forgot about it. About 9 weeks later I saw the film on my carboy as well as a 1g jug, seems strong enough of a film that gas could create a bubble, yet when I tried to turkey-baster it off, it just crumbled and eventually dissolved back into the wine. I racked and added Kmeta and I’ve not seen it return. At the same time I did a Malbec and a Syrah and have not noticed the film in these. Same Acti-ML and VP41 and 9 weeks mental lapse was present.