Machine oil

[Ridenour64]

I just bought a SS Brewtech Mini kettle for small/ test batches. I’ve heard of these kettles having machining oil on them and that they need a good cleaning. Never had an issue with my other kettles. I know they recommend cleaning with TSP but for some reason I ignored that advice and gave it a good scrubbing with dish soap. I brewed on it yesterday and at the end of the boil I saw a black residue near the top of the kettle. I proceeded with transferring the beer to the fermenter and pitching yeast as normal. Sampled the wort and from what I can tell, all is fine.

The beer is still fermenting and today, I filled the kettle with a strong solution of TSP. Should I be concerned about the beer though? Is this oil a major concern if it is in the beer? Food grade?

 

[day_trippr]

You'd have to ask SSBT but I've never heard of "food grade" machine oil.
Especially once it's loaded up with metal bits from the "machining" that turns it dark.
Best you can hope for is non-toxic.
Coupled with what was likely just a film, there wouldn't be much quantity involved...

Cheers!

[edit] Of course as soon as I wrote that I Googled "food grade machine oil". Who knew?
Still doesn't change the fact that if it's dark it's likely post-process ie has metal bits in it...

 

[Ridenour64]

Machine oil and metal debris, definitely sounds pretty bad lol. But it did get a good scrub so I assume any metal debris was wash away and like you said, it was just a thin film of oil. Debating either dump or RDWHAHB. (Pending a sample of course because if something is off when I do, I’ll just dump.)

 

[Ridenour64]

I just sent an email to SS brewtech. I’ll report back..

 

[Golddiggie]

You could wipe the thing down (before first use) with either acetone, or denatured alcohol (or both in turn) to clean anything leftover off. Then wash with soap, or PBW, if you wish. Since both acetone and denatured alcohol leave nothing behind it shouldn't be much of a concern.

I've used both acetone and/or denatured alcohol to clean a LOT of things that other solutions wouldn't even touch.

 

[tracer bullet]

I'm not a machinist but around them and occasionally deal with what they use vs. how I have to clean their parts made for use. Giving that background to say - it seems the majority of the cutting fluids used these days are water based and not actually oils. I can't promise everywhere is like that but it's a trend and seems pretty common. So there's a good chance you did indeed wash it all away.

Now of course that doesn't explain what you saw...

 

[Hans O. Lowe]

(Machinist here) The stuff I use for coolant is a water-soluble oil. In its concentrated form, it's very dark green. It wouldn't float on top though, it incorporates very easily with water. When I start getting oily parts, it's because the coolant is low and the pump is sucking way oil off the top of the coolant in the reservoir.

If it were my brew, I'd just leave that layer of oil on top of the beer when I transferred. Kind of a sacrifice to the beer gods

Good luck and I hope it turns out for you!

 

[Ridenour64]

So as far as the kettle currently, it’s definitely clean now. I filled it to the top with a strong concentration of TSP -> drained and rinsed -> scrubbed with BKF -> rinsed -> scrubbed with oxy clean and rinsed. I’m confident nothing is left.

There is a chance I’m wrong and it wasn’t oil at all but idk what else it would be. What I saw was a blackish residue near the top of the kettle. It was kind of clumping together. This wasn’t visible until late in the boil and I assume was a reaction with the heat of the boil.

 

[Hans O. Lowe]

Most manufacturing oils wouldn't do much at boiling temps. Maybe it was something to preserve the finish during storage/shipping to the end user?

If that's the case, hopefully they chose something mild. Regardless, it sounds like it's clean now!

 

[Ridenour64]

As far as the ingredients that the kettle saw: 6 lbs of Pilsner malt, 5oz of Saaz, Wyeast nutrient, whirfloc, lactic acid.

I assume anything that would be shipped on the kettle would have to be food grade or at minimum non-toxic. I imagine otherwise they would have a huge liability exposure.

 

[Ridenour64]

SS response:

“Hey Matt,

Thanks for reaching out. Since these are designed for use with producing beverages, the machining oils and polishing residue are generally regarded as food-safe, and while we strongly recommend cleaning before use, if any of these do in up in your beer, cider, mead, wine, or kombucha, the worst it should do is just taste a little off. If it tastes or smells bad, you may want to consider dumping the batch but if it tastes fine, then it is probably good to go! I would definitely recommend doing a proper TSP clean before your next batch just to make sure the Brew Kettle is totally clean.”