pump / tubing - lessons learned

[anonymousbrew]

Grabbed a new Chugger - got a little anxious to brew
Did some leak tests. Was waiting for some silicone tubing to come in.
Had a few convos with folks at the LHBS and they were using the braided pvc to recirc wort, and had said "we've never had a problem with it". While i had no intention of using the braided pvc as a final solution, i figured that i could get away with one brew with it no prob. had plenty laying around. The night before ran through the entire brew process with just water, running boiling water through the hoses for quite awhile, thinking, if there is anything thats gonna leech out, it'll do it tonight, and i'll be ok tomorrow when i brew.

The brew went great, no a single problem. LOVED working with the pump - made things very nice.

Threw the APA in the fermenter, tasted the sample, seemed fine to me, i was happy.

2 days in, and the batch hit 1012 and yeast started floccing out, so i took a sample, very excited, until i put it too my nose

smelled like burning plastic bags
tasted like burning plastic bags

so - learn from my cheap ass mistake

go drop the coin on the silicone...its still cheaper than pouring a batch down the drain

 

[Justibone]

Oh, man. Sad.

 

[drummermattie02]

"we've never had a problem with it".

Makes you wonder about the LHBS guys... you'll love the new hoses though.

 

[anonymousbrew]

I'll give em the benefit of the doubt, and assume they were only talking about recirc-ing wort during mash.

 

[SweetSounds]

I'm curious (Not doubting that vinyl is a bad idea, just wondering) - Assuming the vinyl didn't leach anything ferment-able, what could have changed between post chill/pre pitch, and 2 days of yeast farts? Wouldn't the contamination, if caused by something in the vinyl, have been immediately apparent?

If it came about after 2 days of fermenting, it would have to be a byproduct of the yeast munching fermentables - Right?

 

[Catt22]

I've been using braided PVC tubing for years with zero issues. One of my pilsners made it to second place in the nationals last year. I would think that if the hoses were generating any off flavors that it would have shown up in a light lager being evaluated by some of the most highly skilled BJCP judges in the country. JMO, but the off flavors you are detecting may be originating from some other source. I can't think of what that source might be, but unless you were using some kind of really crummy inferior tubing, I seriously doubt that was the problem. Did you mash in a plastic cooler maybe? Scorch a nylon hop bag? Using cleaning and sanitizing methods or product properly? My only point is that the tubing is not necessarily the only suspect in this mystery.

 

[Catt22]

I'm curious (Not doubting that vinyl is a bad idea, just wondering) - Assuming the vinyl didn't leach anything ferment-able, what could have changed between post chill/pre pitch, and 2 days of yeast farts? Wouldn't the contamination, if caused by something in the vinyl, have been immediately apparent?

If it came about after 2 days of fermenting, it would have to be a byproduct of the yeast munching fermentables - Right?

Excellent points. Taking only 2 days to hit 1.012 the ferment must have been on fire! I also agree that any overt off flavors contributed by the PVC tubing should have been in your face from the git go.

 

[anonymousbrew]

yeah, i thought of those too. But other than the pump/tubing, there were no new variables in my process. There are two different types of the braided PVC i used. One seems much more 'crappy' than the other.

 

[wyzazz]

How well did you clean that new pump?

 

[anonymousbrew]

very - before even wiring it up, disassemled, scrubed, soaked in cleaner, dried, then ran hot water through for more than an hour

the least reliable in the series would be the sample tasted when transferring to the fermenter - it was a late friday night brew session

 

[Cpt_Kirks]

I made one batch, a Belgian Pale that is still fermenting, using braided vinyl. I quickly ordered silicone tubing, because using the vinyl SUCKED. It was like wrasslin' with a snake with a bad attitude.

Hopefully, my Belgian won't taste like burnt plastic.

 

[Bobby_M]

The way to test this is to cut a 2" piece of the tubing and put it in a mug filled with water. Microwave it for 5 minutes, let it cool, then taste the water.

 

[JeffB]

Perfect K.I.S.S principle.
Good thought!

The way to test this is to cut a 2" piece of the tubing and put it in a mug filled with water. Microwave it for 5 minutes, let it cool, then taste the water.

 

[wildwest450]

I also use braided pvc for re-circ ONLY, it is FDA and USDA approved and designed for food and bevaerge applications, BUT, it does have a temp limit.

Some are as low as 130f, mine is rated for 175f. I would guess you compromised it in some way by running boiling water through for hours. The tubing itself is not the problem.

 

[Catt22]

I also use braided pvc for re-circ ONLY, it is FDA and USDA approved and designed for food and bevaerge applications, BUT, it does have a temp limit.

Some are as low as 130f, mine is rated for 175f. I would guess you compromised it in some way by running boiling water through for hours. The tubing itself is not the problem.

+1 Keep in mind that often the temp limits are a function of the maximum working pressures. We never come close to the pressures those braided hoses are rated for while handling hot liquids, so there is little chance that they would burst under pressure. I use the approved braided PVC for eveything including pumping near boiling wort and have had zero problems with it. I've also done the boiling water taste test and cannot detect any off flavors in the water. I do take care to clean all tubing with hot PBW or Oxyclean prior to the initial use. I do that figuring there could be some residual lubricants or whatever left from manufacturing the stuff. I do suspect that not all of this tubing is made from the exact same material or the with the same manufacturing methods. There may be big differences depending on the source, but I'm pretty much guessing at that.