Plastic aroma, experimental enquiry

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adc123

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So a few months ago I mentioned in a thread that a high gravity stout (NB Big Honkin' Stout with US-05 yeast) seemed to finish with a high gravity (probably because the yeast just gave up) and had a nasty plastic aroma. Some bottles had it more than others, and it depends on who drank it. Some people didn't taste it at all. I wouldn't say it was "band-aid," or a wild yeast. More solvent-y than anything else. I am pretty careful with oxidation. I always used bottled water or water that comes from a dispenser in front of the supermarket (because California tap water is gross!).

My next brew was a NB low abv saison. I got all new plastic based racking stuff (racking cane, racking tubing, soaked for a long while in onestep). I also tried my first full boil this time, using a friends large boiling pot. I also did all the malt extracts "early," so they were in the boil for a majority of the time. To distinguish the differences, the stout was not a full boil, it used my normal boiling pot (5gal), and added part of the extract late. I also warm my extract up on the stove in a small sauce pan so it flows easier. The saison has much less malt, and half of it is DME, half LME. the Stout is all LME. Both the saison and the stout went into my better bottle ive had since I started. The stout was my fifth beer, and saison my sixth. They both were only in the better bottle for primary, no secondary, and then to bottling. The stout was clearly doing bad things, I could taste the plastic at bottling time. Bottles you crack open today still have the plastic aroma! The saison, however, has been a champ. No off smells, tastes, anything.

I just did beer 7 and beer 8, an ipa(around 6%) than a barleywine(10 to 11%). I bottled the ipa last night. The ipa went back to my old boiling pot, so not a full boil, my late extraction methods, the stove preheating. I used Wyeast 1056 with a starter. From my samples during fermentation, no weird flavors to speak of. I felt pretty confident that I had nailed the issue to something with racking the beer from primary to secondary or to bottling bucket. As I bottled, I took samples. The plastic aroma/taste came back! And it seemed to get worse the more it was in the bottling bucket, leading me to believe the bottling bucket is at fault. But the saison used the same bucket. Perhaps oxidation? If so, it would make bottling impossible given the speed at which I can bottle. I would say the aroma is much less than it was in the stout, but definitely there. What makes this more puzzling is the smell the nearly empty glass secondary(trub and yeast at the bottom) gives off: lots of the same plastic smell, much more overpowering than the beer. Could the plastic have originated earlier in the process?

The IPA was a starter for my barleywine, which has been going for about a week or so. I had been watching that thing to make sure the gravity is going down, which it has been. Samples over the first few days were as to be expected. After I bottled the IPA, I checked the barleywine. No detectable plastic aromas. Its extremely boozy (almost like DFH 120m IPA). The boiling technique was much of the same (late extract, but more water, almost 4 gallons instead of 3). I fear greatly that in a few months the plastic aroma will be in the barleywine.

Now, finally, a plan for the future. I need to track this problem down, changing as few things at a time. Here's what I am thinking:

1) It something with my late extract method. To target this problem, use the same yeast, starter, boiling kettle, etc. However, do all the malt up front, no late extraction. And warm the malt in the sink with hot water. Let it ferment in primary better bottle for one week, transfer for DH in glass secondary. Bottle with new bottling bucket equipment.

2) I could try a full boil again, but keep the late extraction. It could be something with the water. Even though its distilled, bottled, and has no aroma, perhaps there is something funky. Keep everything else the same.

3) A combination of the 1 and 2.

If those don't yield anything, I think replacing the better bottle is all I can do. I clean everything with either onestep or starsan (tap water for onestep, distilled water for starsan), and if it was a bacteria issue I figured the saison would of caught it. Maybe having both chemicals around is bad?

What is also important here is how I transfer the barleywine to the glass carboy. If the problem is in my racking stuff, how do I make sure I don't corrupt the barleywine? I was thinking of getting new silicone tubing and doing it the "old fashioned way" without the cane, just starting a siphon with sanitizer.
 
update: I tasted more of the barleywine. Its near finishing gravity (1.028, don't expect it to get much lower with an OG of 1.109!), lots of alcohol burn, but no plastic aroma or flavor. Even at room temp and left out to oxidize a bit. I don't believe the flavor is coming from my racking stuff since its all quite new. I ordered new tubing just in case.

Reading on the subject, people taste plastic or solvents from phenols. It can orginiate from water or from some wild yeasts. I use all bottled or distilled water in my brewing (but not with my onestep... could be an issue?), so I don't think its from the water. I didn't get this taste from the IPA when I took samples from the primary. It seemed to only develop in the secondary. I am starting to suspect infection from less-than-perfect sanitization. I live near the pacific ocean; bread goes moldy quite fast around here. If my racking wasn't perfect, or the fermented weren't squeaky clean, I could believe a minor infection developed in the beer, leading to this taste. Have people seen this in the secondaries?

Given all my ideas, I may end up never finding the specific cause of this taste, but if it goes away, I wouldn't mind at all :)
 
the only time I have had a 'plasticy' taste was when I bought new racking hose. now when I buy new hose I always boil it in some water first and it seems to help. just a thought.
 
thinking about how it happens, I remember not being as keen on sanitization during the stout fermentation, especially when I racked it to a 2ndary. After the stout I stepped up my cleanliness; however, the IPA got dry hopped with a nylon bag. I sanitized it, I really cleaned the glass carboy, but its possible my manhandling of the bag into the carboy neck did the trick and contaminated it. That secondary reeked the most of all after I put the beer in the bottling bucket. The beer has quite smell, its not just plastic. Its can be sweet on the nose (I am not sure what "cooked corn" smells like), but plastic on the tongue. I took this to be the dry hopping, but now I feel its the manipulation of the hop bag. Its all starting to point to an infection...

It truly helps to write these ideas out! And now people and just search for them rather then the ideas locked away in an un-indexable hand written notebook! Ill keep this thread updated when I brew the IPA again.
 
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