O.K. Try to follow my logic and if you think I've come to the best conclusion. First of all, we cleaned and sanitized every step. We made a 5 gallon batch of Imperial Chocolate Milk Stout. We kegged it. I used my beer gun to bottle 2.5 gallons then added toasted coconut to the other half for a week. Both tasted great out of the keg. We bottled the coconut stout. I kept mine cold and my friend kept his at room temp. A few weeks later all of his had a vinegar taste, but mine were fine. Took one of mine out of the cold and let it warm at room temp for a week and it tasted infected too. All of the regular chocolate stout still tasted fine. I took one of my chocolate stouts and let it warm to room temp for a week to see if it was the cold that was holding back the infection....but it still tasted great. I am concluding that an infection took place sometime between adding coconut and using the beer gun the second time. Does this sound like the likely thing? Most likely the beer gun was culprit, even though I cleaned and sanitized it? Either that, the coconut, or the bottles? I wanted to dip the hop bag of coconut into rum to sanitize it, but my friend was afraid the flavor might mess things up so we dipped it into star-san. Maybe not long enough? Any ideas? I use oxyclean to clean and star-san to sanitize.
Your rum will not sanitize anything. Star San in he proper mixture will kill almost everything in about 30 seconds of contact time. What was your source for the coconut? I would look at maybe baking the coconut in some aluminum foil close to 200°F for a few minutes to kill anything off.
He said he didn't use rum. Also why wouldn't rum work? The alcohol should do the trick--I soak stuff in vodka all the time before adding it to the mix and haven't had an issue. I think with anything though, it's more about contact time. As a side note, toasted coconut does sound awesome for a stout.
I would run through the sanitation procedure on the beer gun (make sure you are doing a thorough job with the oxyclean, PBW or BLC, a lot of crud can build up in those and render the starsan useless) and next time boil the hop bag instead of dipping it in starsan.
I just wanted to state that the rum would not have helped if they would have went with it. Isopropyl will kill some bacteria and germs. Rum and vodka in the 70-100 proof range could kill but the contact time would be far to long..... Weeks even. Vodka is a gamble and much more expensive than Star San IMO. Bacteria will not thrive in the Vodka/Rum however it does not mean that it's killing anything..... Fast enough anyway
If you think the coconut was sanitized properly, I would look closely at the beer gun. I have one and by the looks of them after removing the rubber tip I imagine you could boil the gun. A few minutes in a boil will be sure to kill any beer spoiling critters. Taking a good look at the ball/pin locks on the liquid sides of your beer gun could also reveal the source.
I disagree. It is VERY common to soak additives in vodka or rum in order to extract their flavor (vanilla, cocoa nibs, etc). This process often takes less than a week. Sanitizing the same additives can take as little as 1 day depending on porosity. Check this out for various opinions on the matter: http://beeradvocate.com/community/threads/brewing-with-cocoa-nibs-and-cinnamon-sticks.43181/ I'm not advocating cleaning equipment with alcohol, but it is convenient for ingredients because the necessary volumes are small.
Why in the world would you suggest/even mention sanitizing anything destined for consumption with isopropyl alcohol? Bullshit. 60% Ethanol (120 proof) will kill E. coli, mycobacterium t. and Staph aureus in 0.25-1 minute. Time for cell death decreases as the alcohol proof goes down. If you want a reference: http://books.google.com/books?id=3f...rcentage of ethanol for sterilization&f=false
I honestly don't know if this would have sanitized the coconut. But... IMO dipping a bag of food into starsan isn't going to sanitize it. Starsan sanitizes smooth, properly pre-cleaned surfaces. Just a shot in the dark, but do you have fruit flies around? It's not the season for them here, but I've been seeing them hanging out at a local beer bar anyway, so your vinegar taste made me think of acetobacter.
Have you disassembled the beer gun, cleaned all the tubes and parts with the brush, and soaked everything in star san? Good practice before you bottle.
i guess you've got to dig a little deeper..beer gun, hoses, fittings. i'd got through them all to be sure
If you toasted the coconut and then dipped it in star-san it's probably not the cause of the infection. The beer gun is a strong possibility, especially if you didn't fully clean and sterilize it in between uses. Could be the bottles or caps but that would likely be a less uniform infection. If the infection is widespread it is most likely anything that touched the beer going into the bottles. You can look at better practices to add the coconut should you decide to ever add coconut in the future. However, I do wonder whether the "vinegar taste" is actually the coconut oil going rancid. That would explain why it would go bad at room temperature but less so at cooler temperatures. You are likely not getting a lot of acetic acid in sealed bottles but there could be other acids and off-flavor-producing compounds producing a flavor that could be interpreted as vinegar-like. If there is an actual infection, I would look at all the equipment from beer lines to tap to beer gun. How well cleaned were the individual parts? How well sanitized? What about the keg posts and quick connects? Were they cleaned and sanitized before the second bottling run? Seems like with a pressurized keg you would have a hard time thoroughly cleaning and sanitizing the beer post in a way that would effectively sanitize it. The only way to rule out the beer gun as a persistent source of infection is to give it a thorough clean and sanitation and try using it again. See if the same results occur.
Did you leave the cleaning part out of your answer for brevity, or did you not clean? Starsan is a great sanitizer, but a terrible cleaner.
