Chalky deposits on fermenter

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I've many a brew under my belt with the GF30 and, after transferring to keg, I always just pressure-wash, clean with Chemclean and then rinse with diluted Chemsan until next time, at which point I soak with diluted Chemsan for an hour or two before transferring in the new batch from the kettle.

Up until now, it has always looked like new as soon as I've finished pressure-washing it without even a scrub, but this time it appears to have some kind of chalky-looking residue on it.

I brewed a simple stout using uncorrected tap water (it's already pretty good for porters and stouts) and I'm wondering if it's limescale deposits out of the water, beerstone or something else? Also, why it has chosen this time to appear? Is the beer style relevant?

I've not actually attempted to clean it yet, short of pressure-washing - thought I'd ask for advice first 🙂

IMG_4560.jpg
 
Not sure if it is the same circumstances, but I had issues with chemclean,

I have tried to link the thread below:

https://www.thehomebrewforum.co.uk/threads/chemclean-residue.101585/
If it doesn’t work just search chemclean residue.

Long story short I found that neat Chemsan / starsan removed it really easy. I have really hard tap water and even when only letting it soak for 20 minutes I got the deposit. I got fed up with it in the end and have now moved on to the brauland cleaner. Only used this to clean kegs so far but no issues as yet. Hope this helps.
 
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It looks like the beginnings of a beerstone build-up. Beerstone is a precipitate formed of calcium and magnesium from the water and proteins and tannins from the malt. It is usually just called calcium oxalate; that tannish-brown (sometimes grayish-white) coating that all of us eventually see in our kettles, corny kegs, and other equipment. It starts out looking like a stain but can resemble a coat of paint if left unattended. It’s nothing new as it has been found in the surviving clay amphorae of the Sumerians, Egyptians, and other ancient cultures. They transported and stored beer in these jugs.

If it were only an aesthetic concern, we might cherish it as if it were the patina of an old bronze statue. In reality it isn’t attractive, and more importantly, can cause us problems. One detriment is that in the kettle it acts as an insulator and doesn’t allow all the BTUs from your heat source to get into the wort. In a chill plate, it insulates the beer from the ice bath. The much bigger problem is that it can harbor all sorts of nasty little bugs which can cause infections in our beer. It needs to be removed from time to time. If you don’t, it will continue to collect like so many coats of paint.

Every now and then, I treat my equipment with B-Brite which will remove the build-up. 5 Star Chemicals has come out with a beerstone removers in recent years. If it works as well as their other products, I'll abandon the B-Brite.
 
Just a quick follow-up. I'd not addressed the issue until now because I've not had time to brew for the last 6 weeks, but I have a window later on this week so I needed to try and resolve quickly with what I have to hand. It turns out 10ml of Chemsan in 1 litre of warm water did the job nicely. I sloshed it round and scrubbed with a stiff plastic brush every minute or so for for about 20 minutes and the stainless steel is now as smooth as the proverbial baby's backside again!
 
Pleased it worked for you.

I have had the same issue with the grainfather cleaner on the grainfather since, weirdly it was only on the area where the elements are. I added the cleaner while warming up so that might have not helped. Came off in the same way though.

Im 90% sure it is something in these cleaners that doesn’t like my super hard tap water though.
 
I get that in my fermenters too but I find soaking with warm Puro Oxy solution has been helpful in its removal.
 
Im 90% sure it is something in these cleaners that doesn’t like my super hard tap water though.

I think there's truth in that. Northumbrian Water cite my water as "moderately hard" and it's certainly sufficiently impure to turn Chemsan solution milky. I may well start using spotless water for my cleaning water. It seems like a luxury, but if it saves time, hassle and additional Chemsan for scrubbing purposes, then it could well be worth it.

I don't recall having this issue when I was on Severn Trent, which was pretty much as soft as it comes.
 
I don't recall having this issue when I was on Severn Trent, which was pretty much as soft as it comes.
I’m on Severn Trent and my water is classed as very hard.

I’ve scrubbed mine with Barkeeps Friend and it seems to have done the job, got a brew in it now so I’ll see after that how it’s looking.
 
I've many a brew under my belt with the GF30 and, after transferring to keg, I always just pressure-wash, clean with Chemclean and then rinse with diluted Chemsan until next time, at which point I soak with diluted Chemsan for an hour or two before transferring in the new batch from the kettle.

Up until now, it has always looked like new as soon as I've finished pressure-washing it without even a scrub, but this time it appears to have some kind of chalky-looking residue on it.

I brewed a simple stout using uncorrected tap water (it's already pretty good for porters and stouts) and I'm wondering if it's limescale deposits out of the water, beerstone or something else? Also, why it has chosen this time to appear? Is the beer style relevant?

I've not actually attempted to clean it yet, short of pressure-washing - thought I'd ask for advice first 🙂

View attachment 91240
Crescent city Mike nailed it, and you mentioned beer stone, aka calcium oxalate which is what happens when the calcium interacts with oxalic acid. You also gave the biggest clue as to why you ended up with it. 'Uncorrected tap water'
Prevention of beer stone in your equipment and bottles or kegs is adding some calcium to the water, in the case of your stout calcium carbonate. For lighter beers add calcium sulphate or calcium chloride. The downside is if it forms in kegs or bottles it will cause gushers in bottles and foaming in kegs.
 
Many thanks for the additional information @foxy - both useful and interesting! I think it's something I'll be far more aware of now I've encountered it first hand. I'm starting to correct my water now I've finally got all the additions on hand, so can hopefully minimise its formation in the future 🙂
 
Crescent city Mike nailed it, and you mentioned beer stone, aka calcium oxalate which is what happens when the calcium interacts with oxalic acid. ...
Ah, you're skipping an important "extra", which @crescent city Mike does mention: The "proteins and tannins". This is what acids alone has trouble budging. Calcium Oxalate ... easy-peasy, acid shifts it no problem. But Calcium Oxalate forms a matrix with proteins to give Beerstone and the proteins keep the oxalate together under attack from acids, and alkaline cleaners which attack protein fails where the protein is matrixed with the oxalate. Hence this blog post by Graham Dineley (on his wife's blog):

http://merryn.dineley.com/2021/11/beerstone-is-not-calcium-oxalate-and.html
I've still to tackle my beerstone problem. Not a dusty residue, but something I need to chip off yet its inside a (very large!) heat exchanger. And its presence is very noticeable on performance. I've got a gallon of commercial milkstone (same stuff as beerstone) remover, but as it's 30% phosphoric acid I'm not sure if it'll work yet.
 
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