Strange hose staining

[TGTimm]

We purchased this hose back in March this year:


We use lye and BrewEze for cleaning. Otherwise, nothing but product has been through that hose.None of our other hoses are showing this staining.

We don't use any iodine-based chemicals in the brewery.

I'm completely baffled by this. No chemical will remove it--at least, none that we've tried.

[backslope]

Hard to tell for sure from the photos, but it looks similar to a stain we developed on a pair of hot side hoses a year or so ago. In our case, it was a thin film of recrystallized sugar, we had used some dissolved brown sugar in the boil in a big stout, and we think that during whirlpool it cooled enough to recrystallize and coat the hoses in a thin film. If I recall, we heated water up to boiling and ran a recirculation loop through the hoses for a while, which loosened it up again and cleaned most of it up. Then hit it with super hot caustic followed by an acid wash. Our standard SOPs and chemicals wouldn't take it off until we got the near boiling water to loosen it up.

Don't know if you used an sugars or syrups recently, but that is our experience.

Good luck.

[TGTimm]

No hoses on the hot side, and we use no syrups nor crystal sugars.

I cleaned this with 185F water and caustic. No effect.

[backslope]

Then I guess I am of no help! But I am used to that by now. Good luck figuring this out.

[UnFermentable]

What strength caustic did you use? By lye, are you referring to NaOH (currently most commonly referenced), or KOH (old science)? Is this a formulated caustic with chelators and surfactants added? Time you circulated the solution? Flow rate?

You probably are already in normal ranges based on your level of knowledge, but important to consider turbulent flow rate to try and clean those hoses properly. Laminar flow won’t help much. You can add some “booster” (H2O2) to your caustic solution to really create micro scrubbing action during the cycle, but it’s reaction only lasts about 30 mins. You could also try an Acid/No rinse/non-caustic cycle which works wonders for protein buildups (which I believe this may be). New Brewer Article from like 1993 by Dana Johnson (Birko sage). I believe that’s Ultra-Niter/No rinse/Brew-R-Eze if your using Birko stuff, but any equivalent should be fine.

[dick murton]

This is early beer stone formation - mainly protein at this stage. Not uncommon with inadequate CIP flow rates. Unfermentable has got in first with suggestions for chemical usage.

If this is one inch hose, you need a flow of at least 2200 litres / hr, preferably closer to 3000 litres / hr, if 2 inch hose at least 9,800 litres / hr, preferably closer to 13,000 litres / hr

[TGTimm]

Thanks, folks!

We use caustic--NaOH--at around 2-3% @ 180-185F. Not sure of flow rate, but I can check that now that we have a flowmeter. We alternate the caustic with Brew Eze, not sure of concentration but same temps and pump.

I'll look into some of the suggestions above.

[TGTimm]

Still curious why it's just this one hose out of all of them? All the hoses get used for the same stuff.

BTW, it's a 1 1/2" hose.

[dick murton]

Why that one only? Sorry, but off the top of my head - no idea if it really does get used for exactly the same duties as everything else. 1.5 inch hose - 5400 litres / hour minimum to 7200 litres / hour preferred. If anything comes to mind, I''l update this.

[UnFermentable]

2-3% concentration of NaOH (by volume presumably) should be more than sufficient. I myself don’t often need anything more than 1.5% when using a booster of H2O2, and I use HLT for cycles, but I keep it at 175*F as I recall seeing calcium oxalate precipitation increased significantly above 180*F (excess beer stone on HLT). Definitely hit turbulent flow and that will be your mechanical action to help scrub.

Hosing, I knew this question was probably coming and I should have just continued my thoughts in the first post. Two major thoughts crossed my mind in this regard.

First, perhaps the newer hose was lined with a different material, or had a different surface texture, leading to more protein adhesion than the older hosing. Yes possible, and maybe even likely on a micro level, however I dismissed this thought due to the stainless ends still showing the protein film. The difference in surface is likely not much of a factor because the hosing is all designed for sanitary food processing (presumably). Again, I think that this is protein film, and it will likely flake off in little skins as you hit it with a reverse chemical cycle or add some peroxide booster.

So my conclusion is that the hosing probably just saw more contact with higher protein content, and that is why it developed the film. I certainly notice my beers have different protein deposits on the kettle, based on style, and this is true for all the transfer pipes/hoses as well. Perhaps you were moving more stout than Pilsner through these hoses recently? Perhaps the cleaning cycle was shorted for time, chemical, or flow rate despite SOPs?

[TGTimm]

We never did figure this out. We just ditched that hose--we've been burned badly before--and replaced it. We haven't seen this again.