Plastic-like taste - Pale Ale Recipe

[dogbert]

I did a batch of all grain pale ale, and it has a moderate taste of plastic.

Recipe:
*10lbs pale two-row malted grains
*1.5lbs crystal 60 deg malted grains
*1.0oz centennial hops (45 mins of boiling)
*1.0oz cascade hops (15 mins of boiling)
*0.5oz cascade hops (5 mins of boiling)
*Irish moss (1tablespoon, last 5 minutes)
*Lemon zest (2 tables spoons, no pith, last 5 minutes of boiling)

I was wondering if this is a result of chlorinated water, contamination, leeching from my equipment, or the yeast temperature. Despite pulling off a few decent all-grain lager recipes, this one was bad luck.

The yeast was pitched around 70 degrees F, and that is the approximate temperature of my kitchen, where I let the wort ferment. The fermentation was very rigorous, and popped the airlock off twice, letting the water reach the minimal level. I sterilized the airlock, and re-installed it until I could get a run-off hose system in place.

Also, I did not add any campden tablets, which a friend advised. I don't taste any chlorine in the water from my tap (which I sterilize via boiling), so is this necessary?

Finally, I have a continuous sparge system that works by having a racking cane in the hot water, which is then used with food grade vinyl tubing to siphon the hot water over a metal colander to spread the hot water over the mash. The racking can has warped a little. Would the taste be coming from the racking cane or tubing? The wort did not possess this taste, so I'm doubting it was plastic leeching.

Thank you.

 

[Randy_Bugger]

$500 says your issue is water and chlorine related. Four cents worth of Campden tablet in the water would have prevented it.

 

[ktblunden]

I will also guess that chlorine/chloramine has something to do with it. However, your racking cane and tubing are not rated for the temperatures you're subjecting them to, and I'd avoid doing that in the future.

 

[Wynne-R]

What they said.

My guess is chloraminated water. The EPA requires a residual disinfectant and it’s either chloramine or chlorine. Chlorine has a very strong odor, chloramine not so much. Chlorine is highly reactive but fairly easy to remove. Chloramine, again, not so much.

The effects of chloramine are spotty, sometimes you get away with it. Chlorine is always trouble. Carbon filters do a great job with chlorine, but are less effective with chloramine. Campden is a sure solution, Cheap, easy and foolproof.

If that’s not it, you have done a good job rounding up the usual suspects. A hot fermentation will create off-flavors including fusels, a hot solventy alcohol flavor. As for leaching chemicals out of plastic, that mainly happens above 180F and would fade dramatically after a few uses.

Another source is wild yeast from the air. They can throw all kinds of funky phenols.

 

[dogbert]

So, I think I've found the culprit.

The water quality is pretty good where I live, and my mead has never encountered any issues with this plastic-like taste. I repeated my previous batch, scaled back for a small, 1-gallon batch. I washed everything very carefully, and this time, I did a batch sparge rather than a continuous sparge, so I'm not heating up my siphon tube or racking cane. Same issue occurred. I'm thinking it's possibly residual chlorine from the pink sanitizer powder I use to clean out the carboys.

I wash them out for three minutes with scalding water using a bottle washer connected to my sink, then sterilize them by filling them with k-meta solution until I'm ready to drain it and transfer the chilled wort to the carboy. It then gets one more spray with the bottle washer before transferring.

Would adding a campden tablet to the wort help prevent this issue from occurring? I haven't used them before, but it looks like they are just k-meta (potassium metabisulfite). What does it do, other than inoculate the wort against wild yeast or infection, that counters the effects of chlorine? Could I just add a fixed amount of k-meta instead of the tablets?

Finally, how tolerant to k-meta is beer yeast? The EC-1118 I use for wines and meads is almost un-phased by it, but I'm wondering if it could kill off the beer yeast.

Thanks!

 

[Yooper]

So, I think I've found the culprit.

The water quality is pretty good where I live, and my mead has never encountered any issues with this plastic-like taste. I repeated my previous batch, scaled back for a small, 1-gallon batch. I washed everything very carefully, and this time, I did a batch sparge rather than a continuous sparge, so I'm not heating up my siphon tube or racking cane. Same issue occurred. I'm thinking it's possibly residual chlorine from the pink sanitizer powder I use to clean out the carboys.

I wash them out for three minutes with scalding water using a bottle washer connected to my sink, then sterilize them by filling them with k-meta solution until I'm ready to drain it and transfer the chilled wort to the carboy. It then gets one more spray with the bottle washer before transferring.

Would adding a campden tablet to the wort help prevent this issue from occurring? I haven't used them before, but it looks like they are just k-meta (potassium metabisulfite). What does it do, other than inoculate the wort against wild yeast or infection, that counters the effects of chlorine? Could I just add a fixed amount of k-meta instead of the tablets?

Finally, how tolerant to k-meta is beer yeast? The EC-1118 I use for wines and meads is almost un-phased by it, but I'm wondering if it could kill off the beer yeast.

Thanks!

Campden (potassium metabisulfite) isn't added to the wort- it's added to the water. There is a chemical reaction that takes place that removes the chlorine and chloramine very quickly. The general amount is one campden tablet per 20 gallons of brewing water. Crush the tablet and dissolve in a little water and then pour that into your brewing water and stir well.

You could use k-meta, but it's such a tiny amount that it'd be difficult to measure the powder. One campden tablet would be equal to about 1/6 of 1/4 teaspoon, or thereabouts. I supposed it could be weighed on a small gram scale, but I don't know how much it would weigh. It could be calculated, by someone other than me.

Brewers yeast is pretty tolerant of k-meta, but when you use it to the water for brewing there isn't any k-meta left in the water due to the chemical reaction. I don't know about using it for sanitizing beer equipment, as I"ve never done that.

I've never had chlorophenols in any of meads or meads, and I use tap water. But for beer, the chlorophenol taste happens where the chlorine interacts with the phenols in malt (and hops, I believe). That may be why you've never encountered this with your meads, but have with beer.

 

[dogbert]

Thank you for your time and assistance. TIL something

 

[dogbert]

Good day everyone.

I figured I owed the community at least as much as to follow up on the original question.

I decided to do a deliberately flawed experiment with 4 carboys, each only a gallon in size. Two without treating the water for chlorine and chloramine, and two with treatment by carefully weighing out potassium metabisulfite with a precision scale, and adding the appropriate amounts to my wort water (pre-boil). From each of these two groups, one had water just poured in from a sterilized pot, and the other had hot water run through a food safe vinyl siphon hose. In short:

1) Batch 1: Untreated water, supplied through an over-heated siphon
2) Batch 2: Untreated water, supplied directly from the tap
3) Batch 3: Treated water, supplied through an over-heated siphon
4) Batch 4: Treated water, supplied directly from the tap

In short, the over heated siphon hose imparted a very small, but noticeable taste, and after so much heat abuse, it has become rigid and cloudy white colored, instead of supple and clear. It wasn't really a plastic-like taste, but more of a weird, unpleasant sweet aroma. Almost a burned smell. I had to notice it while deliberately anticipating it, so I would assume most brew masters and gurus here would have picked up it either way.

As for the water treatment: BINGO! Just that little half-a-cent addition of sulfite helped rid me of the terrible plastic taste dilemma. However, this time around, the taste wasn't quite as bad (still revolting) compared to last time.

So, I think it's a combination of rushing too much on my part, the airlock popping off, not treating the water in advance, and using the siphon for a simple continuous sparge system.

I just do batch sparging now, and treat the water, and the brew tastes fantastic. I've also since replaced the airlock with a small length of a racking cane that fits perfectly into the bung, which then connects to a siphon tube that terminates in a large pot of cool, sulfite treated water, acting as a DIY airlock with a better flow rate than the small ones. A small weighted magnet holds the tube in place so it doesn't accidentally fling out of the pot from the pressure. I don't even have to worry about any krausen overflowing and allowing the airlock to server as a contamination point of entry, as the increased flow rate prevents krausen buildup entirely during a vigorous ferment.

Thanks all!


This was carried out using just some liquid malt extract, and just some cascade hops in pellet form.

 

[ktblunden]

Good to hear you nailed it down. I had a similar issue where I suddenly had two batches in a row with strong chlorophenols. My water utility company suddenly increased the amount of chlorine in the water. I started filtering and treating with campden and the problem went away.