Hi all, newbie sour brewer here. Just want to verify this is mold growing in my Flanders Red before I dump it down the drain. Thanks
Yep.
Double yep. But taste it first, you never know, especially when it comes to that style.
Where is the mold? In that pic it looks like mold growing on a krausen ring. If there is no mold touching the beer you’re fine, just rack to a new fermenter and minimize headspace. Hell, even if there was some on the surface I’d rack out from under it and taste it. I certainly wouldn’t dump it without further investigation. Just my 2¢
Everyone has their own risk and safety threshold, but you cannot simply “eat around” mold. There is more than what you see and if the mold is toxic what you don’t see is likely to contain more toxins (root threads).
Whether it is harmful depends on what kind it is, if it is toxic or causes allergic reaction.
People eat moldy cheese
Not a great analogy…not all mold is the same
Agreed
I would rack it out of that and see what happens. Mold is a bummer on any style, but especially a Flanders Red, given the time invested.
Absolutely not an accurate comparison. I would not want to get anywhere near that beer, thank you very much! I have read that the yeast used to make a Flanders Red has produced mold. But I don’t believe it’s produced to the extent apparent in your photo. Dump it!
When I was using StarSan as my primary sanitizer, I used to see little spots of mold in my fermenter. It was still tasty beer. However, I’ve moved back to using Iodophor as my primary sanitizer and that has solved the occurrence of mold in my fermenter. StarSan is ineffective in killing mold spores while Iodophor does kill it.
I wouldn’t even consider pouring out this beer without tasting it.
I am firmly in the “taste it before considering dumping it” camp.
Is this mold at the lip of the vessel? If so, it may not be anywhere in or near the beer.
Mold is not an issue unless it comes into contact with the beer. If it comes into contact with the beer, then any mycotoxins can be distributed throughout the beer since it is liquid and not solid. You cannot identify whether a mold is toxic based on what it looks like, despite old sayings about red and black colors. Chances are that it is not toxic, but there is always a chance that it is. If it hasn’t come into contact with the beer, rack the beer into a new vessel (CO2 purge the vessel beforehand).
I’ve written more about mold in beer here, with references for further reading: Mold - Milk The Funk Wiki
Whether or not you are drinking or dumping the beer, I believe you should determine root cause and how to kill it permanently. Martin’s recommendation (above) sounds pretty good.
For anyone who doubts the inefficacy of Star San, I can testify: I have had mold grow in my bucket of Star San.
Same. And yet I continued to use it to sani my fermenters, even though I saw globs of mold* in it. Interestingly, I never got an infection, so whatever mold was in my star san, it did not like wort.
*At first I thought the globs were chemical, not biological, and so I did nothing. It was only when I put a sample under the scope that I realized it was hyphae. Lesson learned. Now I only use iodophor.
I’ve been lucky too. Yet, irrationally, I still keep it for use in a spray bottle for quick squirts on fittings, countertops, etc. But I think ethanol or isopropyl would be a wise replacement for this. Otherwise it’s iodophor 99% of the time.
If you use Starsan correctly, it works fine. It’s not meant to be stored, so I would guess that is the source for some peoples problems with it.
The mold on the inside of the neck of the carboy is a somewhat typical thing in aged sour beers, especially if you have dried krausen on the inside there. You are likely to find people who sanitize with iodine who have had the same experience. The issue isn’t likely the sanitizer, it’s likely either a problem with cleanliness or the lack of oxygen control in those airlocks (via vacuum usually, or a bad seal). StarSan only sanitizes clean surfaces, and air from the environment getting into sour beers creates all sorts of problems from mold to acetic acid/ethyl acetate and THP.
I use BetterBottles with DryTraps and have never had an issue with mold in 7 years of making almost exclusively aged sour beer. I haven’t used any type of sanitizer whatsoever in the last 4-5 years for my carboys unless I am switching up to a new culture, which is rare because I tend to use the same cultures (I blow through a lot of PBW though to make sure things are clean). I think the DryTraps are no longer in production though and I’ve heard that finding them now is difficult. You might want to think about moving to a keg with a spunding valve on it for long term sour aging.
As a side note, I know that the idea that StarSan doesn’t kill various microbes is a fairly widely adopted thing around here, but in this case there is evidence to be skeptical of the authoritative sources on this claim (as well as a lack of evidence for authoritative sources that do claim it, like food science sources). If you want to read up more on that, we have a section for it on the MTF wiki on the Quality Assurance page with references.