Brass Fittings for Mash Tun

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BillyBock
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Brass Fittings for Mash Tun

Post by BillyBock »

I'm converting my 5 gal. Gott by adding a 3/8 ball valve in place of the original spigot and then connecting it to my false bottom. I've read about the procedure to clean the lead off of brass (soak in 2 parts white vinegar to 1 part hydrogen peroxide for 5-15 minutes). Is this a one-time good deal, or do you have to repeat this procedure periodically? Are there other brewers that are long-time users of brass fittings? Any negative flavor effects or comments (good or bad)? Thanx.
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Mesa Maltworks
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De-passivation of brass valves...

Post by Mesa Maltworks »

You should not be concerned about brass valves when used in mash tuns. The temperature is not hot enough to promote much leaching and the contact time and surface is too small to produce a noticable effect. Actually, stripping the oxidized surface of brass would be worse than leaving it alone. This oxide actually shields the copper/tin elements in brass from being leached into solution if the contact time/surface area/temp was large/high enough. This is also true of stainless steel. When I clean my 20 bbl. jacketed fermenters with nitric/phosphoric acid blends to remove calcium and beer stone accumulations, I have to follow it with a rinse and subsequent drying time to "passivate" the surface for the same reason. Brass is much softer and if brushed or cleaned in an abrasive and frequent manner, it will lead to cleaning difficulties due to pitting and scratching. This is actually the reason most brewers end up avoiding them. If you are careful, there is no reason you can't use them in mashing. Where I would avoid them is in the brew kettle because the temperature and contact time is much higher and the pH is typically lower. 1/2" SS valves are about $ 20 USD and are the way to go as they will last longer in high heat conditions and are very cleanable.

Eric Watson
BillyBock
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HLT & Kettle

Post by BillyBock »

Thanks for the reply, Mesa. So as I understand it, once you de-lead the brass, that's it--no more de-leading necessary. The main concern at that point is the leaching of copper/tin into the acidic wort. I just had a recent thought of also using a Gott as an HLT. I assume that I should also not be concerned about using brass valves in HLTs either (for the same reasons mentioned)? As far as the kettle, do you know where I can purchase a SS kettle (30 qt. min.) which has a diamater no greater than 13"? I currently use a King Cooker and it's burner stand has a raised retaining lip for the kettle. I'm currently using the aluminum kettle that came with it and, of course, am going through great strides to take care of it to avoid pitting, etc. However, I would like to upgrade to a more durable SS model, and given the diameter restriction, I'd rather not buy a new stand as well. Any help you can give is appreciated. Thanks.
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Mesa Maltworks
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Passivation is not related to lead...

Post by Mesa Maltworks »

"...So as I understand it, once you de-lead the brass, that's it--no more de-leading necessary"

No, passivation is only the buildup of oxidative film on the surface of raw metal. You cannot de-lead metals that contain them as they are alloys that are not in layers, but rather each metal is bound together through and through. By passivating the surface, you reduce the leaching of metals into the wort whether they be lead, copper, stainless... etc. By the way, copper in small quantities is good for wort. Brewers with stainless steel kettles and wort chillers have been known to add copper sulfate or even toss in pennies or copper pipe/fittings to aid the nutrition of the wort for better fermentation. Keep in mind though that it doesn't take much !

What I tried to impress with my reply was that since there is such a small surface area that is in contact with the acidic wort, there really is no concern. Where it becomes a concern is in fixed or semi-fixed installations that use copper piping throughout the system. It is here that leaching of metals can be an issue.

"...I assume that I should also not be concerned about using brass valves in HLTs either."

Answer: Correct ! See above and last post.

"...As far as the kettle, do you know where I can purchase a SS kettle (30 qt. min.) which has a diamater no greater than 13"?"

Answer: No... I ran into this issue trying to boil on my ceramic glass stove. The burner circumference combined with the clearance under my vent hood made for a similar requirement... I have yet to find a suitable pot for use in this case. I use my 1 barrel system for this size of batch instead.

Eric
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