# Gaggia Classic cleaning - tartaric acid or citric acid?



## dta (Feb 21, 2012)

When I bought my Gaggia Classic about 8 years ago I was told to use the Gaggia descaler, which was 3 packets of 30gm tartaric acid. This has been discontinued, and the current Gaggia descaler is a bottle of liquid and one use only. This is mainly citric acid. So can EITHER tartaric acid OR citric acid be used? Of the two, Tartaric acid is much more expensive to buy (I get from my local homebrew shop). So if citric acid is just as effective (and does not cause any damage) then I would prefer to use this.

Any ideas, please?


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## jimbow (Oct 13, 2011)

I have been thinking about this a lot recently myself. Looking around the internet and forums there seems to be a lot of differing opinions and often conflicting advice causing confusion over which descaling solutions are safe to use with an aluminium boiler (as found in most Gaggia domestic machines).

From what I have read, most people seem to be divided between using citric or tartaric acid based descaling solutions and are further confused as to whether they should use the Gaggia/Saeco branded descaler, a third party espresso machine specific descaler e.g. Puly Baby, Urnex Dezcal, etc. or commonly available citric acid or lactic acid from chemists, etc. Whilst I might not be able to provide a definitive answer, I can at least share with you my own thoughts and opinions based upon my thinking so far.

Most of what I have read unfortunately does not seem to be based upon empirical evidence which suggests that it might be based, at least partially, upon the following:

1. The older Gaggia branded descaling powders are tartaric acid based and people have extrapolated that therefore tartaric acid should be used. Interestingly, as you pointed out, the newer liquid Gaggia branded descaler is citric acid based.

2. Aluminium and citric acid react to produce aluminium citrate which is more easily absorbed into the human body.

My main concern with descaling the Gaggia boiler is that the boiler itself is not just made of aluminium but rather comprises both aluminium and brass parts. The presence of these two dissimilar metals means that galvanic corrosion could occur when the two metals are in contact with an electrolyte solution as they are during the descaling process (and possibly during normal operation depending upon the pH of your brew water).

I know very little about chemistry but to protect the aluminium part of the boiler, I would have thought the descaling solution should contain an aluminium specific corrosion inhibitor and ideally should passivate the metal to reduce further corrosion from steam during normal operation following the descaling process. I know that the Gaggia branded liquid descaler and the sachets of Urnex Dezcal (both citric acid based) include aluminium specific corrosion inhibitors and there may well be other products too.

One note of caution, looking at the ingredients on Dezcal, it would appear that only the powder sachets include the inhibitor and that the tablet and liquid based versions of the product do not.

Hopefully there are other people on the forum who might be able to provide a more definitive answer.


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## RoloD (Oct 13, 2010)

I and, I believe, many others here use citric acid for descaling their Gaggia. If you buy Puly Baby (which I believe is approved for/by Gaggia) you are basically using citric acid. I have not heard any actual evidence (as opposed to speculation) that citric acid will do any harm to your Gaggia or your body.


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## jimbow (Oct 13, 2011)

Looking at the SDS for Puly Baby it appears to be a combination of citric acid, mallic acid and sodium citrate. My school boy chemistry suggests that the sodium citrate would act as a buffer for the acids thereby providing some protection to the boiler.

Whichever solution you use, I would still suggest leaving the solution in the boiler for no longer than 20 minutes and making sure that the machine is switched off as much as possible during the process.

It is good to know that Gaggia recommend a product for descaling (beyond their own branded product) - can you remember where you saw this stated?


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## RoloD (Oct 13, 2010)

jimbow said:


> It is good to know that Gaggia recommend a product for descaling (beyond their own branded product) - can you remember where you saw this stated?


 Ahh - I may have imagined that. I think it was a case of resellers recommending it for Gaggia rather than Gaggia recommending it themselves. I apologise.

However Bella Barista, who should know a thing or two about coffee machines, recommend citric acid as a descaler and sell it on their site.


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## jimbow (Oct 13, 2011)

No worries, makes sense - I was just interested if it really was recommended by Gaggia.

I have no personal experience to back this, but for the reasons I mentioned above, I would be cautious about using pure citric acid (without some sort of buffer salt or corrosion inhibitor) in an aluminium boiler. It should work fine with all copper or brass boilers however.


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## Roger120 (May 4, 2020)

I have used 50g of tartaric acid dissolved in a tank full of water in my Gaggia Synchrony Digital (Aluminium Boiler) for 35+ years with no problems. I have bought the acid from brewer's supplies 1 or 2 kg at a time kept in a sealable container.

I now have a Gaggia Brera that specifies Gaggia decalcifier.

Gaggia decalcifier has Citric acid Monohydrate <25%, Lactic acid <10%, and water >= 65% ***

Does anyone know how to translate these percentages to grams of powdered acids to add to water?

*** Figures taken from -

GAGGIA DECALCIFIER 250ML

SAFETY DATA SHEET

From Phillips


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## bananapeal (Jun 21, 2020)

> Gaggia decalcifier has Citric acid Monohydrate <25%, Lactic acid <10%, and water >= 65% ***


 i want to bet real money that they are using weights to make these percents. so it should translate directly no? they don't publish a density for you to verify this but they do publish an acidity (which seems really high!) so you could take your citric monohydrate and the lactic acid and add them to water using the weight proportions above and test the ph using meter they use for pools? see if you get 2.1? then you'd say you're in the right place!


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## allikat (Jan 27, 2020)

Yeah, given water is 1ml per gram, it does make replicating things. take 65ml of water, add 25g of citric acid and 10g of lactic acid. Solution should then weigh 100g.

Of course, that's then the concentrate made so assuming that it's used one bottle per litre, you could add the same amounts of acids to a litre of water if you want to do it that way around and start the decal with an emptied tank.


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## light87 (Oct 4, 2013)

Hi

I restart this old thread because I'm trying to descaling an alluminum boiler, I have tried a solution of cictric acid and water at 15% but it haven't cleaned it that good, scale is still there in many points. I also have a product that should be mostly sulfamic acid with a litle citric I think it's powerfull, do you think that I can tried it or it can ruined the alluminum?

Thanks.


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## Alfieboy (Dec 26, 2018)

Do you have any photos as some are not as bad as they look?

You may need some manual intervention too


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## light87 (Oct 4, 2013)

Yeah it's really not that bad, I just would like to removed all the scale before mouting again, expecially on the botton of the inside cavity.

Sure I will use the metallic brush for some part, maybe with proxxon, not for all anyway.


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## allikat (Jan 27, 2020)

Don't try to get the aluminium all shiney, the dull coating inside will reform anyway. I'd suggest that all the usual compounds are fine for descaling so long as you rinse it thoroughly afterwards. Did you try the descaler in hot water? The heat helps it all work well. When I descaled my Baby, as part of a full strip down, I put the boiler in a plastic box and added near boiling water and let it sit till cool and all was good. If you're doing it with the machine assembled, then let the descaler sit in the boiler with the power on for at least 5-10 minutes before flushing the system out.


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