Checking kegs for beerstone

I am wondering how many others have done a close inspection of the interior of their cornie kegs?  I happened to be cleaning a few in the bright sunlight and was able to detect some areas that looked like scratches, but upon feel, turned out to be rough patches that felt like sandpaper.  I did prolonged soaks in alkaline cleaner at high strength followed by an oxalic acid soak and finished with a strong Starsan soak.  The beerstone came off with some scrubbing with a stainless steel safe pad, but getting at the bottom of the keg required some McGyvering with a long handled clamp…I have been pretty meticulous in my past cleaning regimens, but I will be taking extra care going forward to look closely with a bright light at the interiors of my kegs as they kick.  Just another thing to watch for in homebrewing.

Cheers!

I inspect my kegs for issues at every cleaning using a bright flashlight. I used to be an aircraft inspector so it’s kinda built in. I have also detected beerstone in my kegs. I use B Brite for routine cleaning and light build up and Milkstone remover for heavier jobs. I’ve yet to find a good way to get to the bottom of the keg.

I’ve never been trusted to inspect an aircraft, but I also inspect kegs every time.  Because  I know from experience what a PITA it is to remove milkstone when it really builds up.  PBW for routine cleaning, followed by an acid rinse of milkstone remover if I feel like bothering; an occasional alternate routine of hot acid cleaning with milkstone remover first, followed by PBW (no rinse in between) – the idea is that the acid loosens deposits so the alkaline cleaner can remove them; and a long soak in milkstone remover followed my manual scrubbing if it gets out of hand.

To get to the bottom of a keg, go to a janitorial supply store and get a floor drain brush.  It’s like a giant bottle brush on a broom handle,  works like a charm, and the fire department will never have to come get your arm out of a corny.

I have a cleaning regimen that seems to work.

  1. When a keg gets empty I flush it several times with tap water (swirling), and then put about a gallon of tap water in, attach the lid, and shake it a bunch of times. Then I push the water into a waste vessel using CO2 and the out post. At that point I do one more rinse, add another gallon of water, and let it sit for several days. My water is alkaline (no, I don’t use it to brew), and it seems to remove most of the remaining gunk.

  2. The second stage is a prolonged soak using 5 gallons of 0.2M tri-sodium phosphate. TSP is an alkaline cleaner best noted for removing paint, but it works wonders on whatever gunk remains in the keg. A keg that has been cleaned in this fashion has a beautiful frosty stainless steel appearance inside!

  3. After a week or two I rinse the keg as in step 1, and fill it with 5 gallons of StarSan. It will stay in the StarSan until I push another keg through the cleaning station.

At any given time I have three kegs in the cleaning station: One with water, the next is full of TSP, and the third is full of StarSan. I change the TSP when it begins to look brown’ish, and the StarSan every other month. I have been doing this for about 5 years, and so far so good. :wink:

Charlie

Organic removal first, followed by mineral deposit removal. So some sort of high pH soak (lye, PBW, Alkaline Brewery Wash) is the first step. I understand that if those organics are acid washed first, they become harder to get off.

A strong acid soak or rinse is next and it does need to be a pretty strong acid in order to dissolve beerstone. An important note is that hydrochloric acid (aka: muriatic acid) can’t be used on stainless steel or it will oxidize (aka: rust) even stainless. Many other acids can be used, but they do need to be Strong Acids (chemistry term) for them to be highly effective in dissolving deposits.

I’ve been using a straight toilet brush (dedicated to only keg cleaning!!) for keg scrubbing and it works decently. I still occassionally see a streak of beerstone in some kegs. I’m not a big fan of using scrubby pads on stainless since those pads are abrasive enough to scratch stainless. I prefer to use thumbnail, credit card edge, or plastic putty knife for attacking surface buildups on stainless.

I do like to use those free LED flashlights that Harbor Freight gives away for inspecting kegs. Nice bright light and they fit into kegs.

Cannot you just use beer line cleaner to remove beer stone?

No, you need an acid to loosen and remove the calcium oxalate deposit.  That’s why you clean draught lines every two weeks with BLC, and quarterly with acid line cleaner in addition.  The alkaline BLC won’t prevent the buildup.

I have found that selecting a proper cleaning chemicals is the biggest challenge in brewing.

Thanks, makes sense.  I didn’t realise BLC was alkaline.

Looks like five star do a product. 

Milk stone remover, available at places like Tractor Supply or a dairy supply store, is great stuff.  We used to use it on the farm to remove milk stone from a bulk milk tank and it works equally well on beer stone.

In addition to using PBW to clean the organics out of the kegs, I will sometimes also do a caustic caustic cycle to provide even more cleaning power, it is just more dangerous to use so additional care is needed.

Nice comment on the floor drain brush, Rob.  It paints a vivid picture of seeing the rescue squad coming to your house and using the jaws of life to extract your arm from the keg!  ;D

Yes, but that is unnecessarily expensive if you have access to an alternative, dairy milkstone remover.  They are both identical in composition (~40% phosphoric acid) made to remove the same deposit (calcium oxalate, call it milkstone or beerstone as you please) in a food/beverage operation.  But dairy farmers won’t put up with being gouged the way homebrewers, or perhaps even commercial brewers, will.

And even if you keep your arm, you’ll lose a keg to the jaws of life!  Money down the (floor) drain! [emoji6]

I have no problem selecting them, but most of the stuff I want is not available to consumers.

When I worked at the Med Ctr all I had to do was put in a purchase order, and the stuff magically appeared. But these days 68% HNO3 and 85% H3PO4 is about as easy to find as a unicorn!

Charlie

True, Charlie.  If you have a pro brewer friend at a local brewery, he/she might be able to get some for you.  Several years ago, I got a gallon of 75% phosphoric from the brewery I worked for and it will probably last me for the rest of my life.  I can also get caustic when I need it from another brewery and a gallon of the stuff lasts me quite a while since I primarily use it to clean my beer lines (way cheaper than BLC).

You might also want to contact a local cleaning supply house and see if they might be able to order some of this stuff for you.  Nitric acid might be a bit harder to come by but they may be able to order KMS-10 (which is the same stuff) from Loeffler for you, provided they have an account with them.  Or you can just milkstone remover from a dairy supply outfit, as Rob mentioned which is much cheaper.

True. You could go to https://www.brewcitysolutions.com to buy your stuff. Issue is that the smallest package you can buy is case of 4 1 Gal jugs (if you are lucky).

Thanks for the link, Thirsty Monk.  Just looked at their site.  Looks like if you buy caustic from them (their alkaline kettle cleaner) the smallest quantity you can buy is a 5 gallon pail.  Since the product contains sodium hydroxide, the shipping costs will would be prohibitive for a homebrewer since it will most likely have to come by truck.  UPS and FexEx normally won’t transport hazardous chemicals that are in quantities larger than a quart.  I learned that from Five Star a few years back when I asked if they could ship gallon jugs of Saniclean to me.

True. They also have a powder that can be shipped thru FedEx and others.