Possible contamination after racking

[E Ray]

Hi all,
This is my first time brewing anything. I started off making a hard cider from my parents’ Apple tree. I bought a apple crusher/presser and got about 4 gallons of juice. I added this to my 5 gallon carboy plus 4 campden tablets, and let it sit 4 days. I added one more gallon of pasteurized apple cider from the store plus Cider House Select yeast. Fermentation seemed to go fine—it eventually died down and I let it sit for a little bit before racking. I racked about a month and a half after pitching. All equipment was washed and then sanitized with iodophor and hot water, let it sit for a half hour before using… during racking I split off a little to a glass and it tasted good. Initial gravity was 1.048 and final gravity during racking was 0.999. Well about 10 days after racking (it’s day 12 now) I noticed lots of little white spots floating on top. I assume this is bad, and something must have contaminated it. I’m not sure where I screwed up, but it must have been during racking. I’m attaching a photo if that helps. But I really want to know—is there any way to save this while I’ve caught it kinda early? Can I add more campden tablets now? Is there a way to sterile filter it?

 

[Rish]

Kinda hard to tell from the photo. Could be yeast rafts. Campden won't hurt but it may not need anything. How does it smell/taste?

 

[CKuhns]

Yes, hard to tell. Could be yeast as @Rish has suggested carried up with some disolved CO2.

Small (or even large) white rafts are usually not a concern. Small like that have never been an issue for me. Large white bubbles or a white film are typically lacto basillus bacteria. Again not too problematic, some folks actually try to get them in thier cider as it adds some interesting flavor.

Campdrn wouldnt hurt. Rack it and if your concerned leave the white stuff behind.

Yes you can filter it but you must get a filter media down to about 0.3 micron to get most bacterias. Yeast and other solids will quickly clog filters up. Start with a 10 micron then 5 then 2 then 1 and finally 0.45 micron before the 0.3 micron. You would likely need a pump and will also strip some color and flavor.

If they are colored. Red, orange, purplish, green (sometimes fuzzy) then it is infected and should be dumped.

 

[E Ray]

Thanks for your replies. For it to be yeast rafts, would it have to be actively fermenting still? Looked like about all activity had ceased for a while before I racked it. My day job is in a bio pharmaceutical analytical lab, so my first inclination would be to sterile filter it through 0.2 micron. But that’s when I’m not actually paying for it, haha. Not sure I want to invest in a pump and equipment just to save this batch. I’m keeping an eye on things at the moment, and it doesn’t seem to be getting worse. Actually the number of floating spots seems less than a few days ago—I think stuff is settling to the bottom. I guess it could just be a phase though. If they start multiplying again I will probably add campden. I’m gathering that as long as they are white it is likely not too harmful. But I think when I’m all done I’ll be pouring into a glass before drinking, instead of drinking from the bottle. I guess another thing I could do if I’m worried about unknowns continuing to grow is bottle and then pasteurize. Thoughts on that? Okay if it’s a still cider?

 

[Chalkyt]

You might be interested in the attached article from WSU. It was originally posted here by Jaypkk on 4 Dec 2020. Basically, it indicates that pasteurising stops yeast quite quickly but suggests that more research is needed for destroying other organisms. For cider 30 -50 PUs seems to be the target to stop fermentation and this can be achieved by heating up to something like 65C in about ten minutes then cooling down. I do this to stop at the carbonation (or sweetness) level that I want, and as a side bonus don't seem to have any infection issues (mind you, everything is cleaned, sanitised, etc, etc, as well). Intuitively it seems to be reasonable that this level of pasteurisation should kill anything, but I don't really know. In any case, pasteurising is probably worth a shot for you.