Salifert Kit Confusion

(That's water to the rest of us!) Beer is about 95% water, so if you want to discuss water treatment, filtering etc this is the place to do it!
MyQul

Salifert Kit Confusion

Post by MyQul » Sun Nov 12, 2017 1:23 pm

I bought some more CRS/AMS solution recently and it possibly seems a lot stronger than the older stuff.

This is the stuff I bought

http://www.thehomebrewcompany.co.uk/...rs-p-1361.html

With the old stuff I never used to bother testing my water with the salifert kit before acidifying as the alkalinity of my water is always about the same. I just need to use 0.87ml x whatever L water I'm treating and that normally gets me to where I want. I just test my water with the salifert kit after I've treated it to make sure.

So as usual I treated my water for brewing tomorrow with 0.87ml x L of water. I then proceeded to test the water after acidifying it. I put 4ml of water in the little test tube but when I added 4 drops of KH-ind blue dye the water immediately went pink. This was without even adding any of the KH reagent. This is also partly what puzzles me, I havent even added any of the re-agent before it went pink. I've never seen this happen before

I'm guessing the acid it a lot stronger than the last bottle, to cause this. I'm also assuming that the water is fine to brew with as I now have no idea what the alkalinity is other than I think it's quite low

Comment? Ideas?

Edit: I've just done a little experiment. I tried half the amount of acid in one litre of water and when adding the blue dye it seems fine, it's blue. I take it this means the new acid I have is a lot stronger than the old stuff and I'll need to work out by trial and error how strong?

Edit 2: Having tested what this acidified 1L of water's alkalinity is, it comes out at 28 PPM. So unless my water has suddenly halved in alkalinity (perhaps I should test that too) it seems the new acid it about twice the strength of the old stuff. I bought two bottles too so I didnt have to but any more for a while.

User avatar
vacant
Even further under the Table
Posts: 2167
Joined: Mon Aug 20, 2007 5:39 pm

Re: Salifert Kit Confusion

Post by vacant » Sun Nov 12, 2017 6:41 pm

Your conclusion seems reasonable and it sounds like you know what you're doing.

My salifert kit came with a pH7 test/reference solution. If you have the same you could double check your kit.
I brew therefore I ... I .... forget

User avatar
Kev888
So far gone I'm on the way back again!
Posts: 7701
Joined: Fri Mar 19, 2010 6:22 pm
Location: Derbyshire, UK

Re: Salifert Kit Confusion

Post by Kev888 » Sun Nov 12, 2017 6:48 pm

If your water has previously been truly stable and you tested your results after treatment then okay, that was economic. But now something has changed, then the water is the most likely candidate; surely it is important to know what water you are starting with before treating it?

The CRS shouldn't have changed unless a new specification has been issued, though IIRC Murphy's don't have a 100% record of accuracy with their acids so a mistake isn't completely out of the question. It is also slightly possible that your test kit may have become contaminated, though again this is pretty unlikely unless you did something unusual; as vacant says, some come with check solutions to verify the results.
Kev

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: Salifert Kit Confusion

Post by MTW » Sun Nov 12, 2017 7:52 pm

My water dropped so far in alkalinity for one brew in September, that I only needed HALF the amount of CRS as usual to get it down to the 20-odd ppm, I wanted. And that's from the same bottle. Typically 120-130ppm CACO3 here; that day it was 70 or 80. 10ml AMS instead of around 20ml in 35L. I recall it doing a similar thing that sort of time last year and I assume something goes on with the water sources locally. Checked, rechecked. The rest of the time I get a fairly stable 120-130 (confirmed by a lab test once), but it is prone to the odd blip.

Best to keep an eye on it at the tap!
Busy in the Summer House Brewery

MyQul

Re: Salifert Kit Confusion

Post by MyQul » Sun Nov 12, 2017 8:21 pm

Thanks guys. Fro what you're saying maybe I would test my tap water more often (and my kit too to make sure its not contaminated)

User avatar
Dennis King
Telling everyone Your My Best Mate
Posts: 4227
Joined: Sat Aug 11, 2007 7:52 pm
Location: Pitsea Essex

Re: Salifert Kit Confusion

Post by Dennis King » Sun Nov 12, 2017 10:26 pm

It's good practice to always check the alkalinity before each brew. Mine does change, not by much but it if your going to treat water you need the correct starting point.

Dave S
Even further under the Table
Posts: 2514
Joined: Sun Apr 01, 2012 5:38 pm
Location: Wirral, Merseyside

Re: Salifert Kit Confusion

Post by Dave S » Mon Nov 13, 2017 11:33 am

My water is very stable at about 195 but I (almost) always check it before every brew. The only times my treatment has been awry was when, (guess what!) I didn't check it beforehand and it had strayed from its usual 195.
Best wishes

Dave

Carnot
Piss Artist
Posts: 162
Joined: Wed Sep 13, 2017 8:32 pm

Re: Salifert Kit Confusion

Post by Carnot » Tue Nov 14, 2017 5:45 pm

This is my opinion , but no self respected water chemist would rely on a Salifert or any other drop test kit (Palintest included) for accuracy. Personally I would not waste my money. The best option would be to buy a 10 ml auto zeroing burette and some methyl orange indicator. You will then need a standardised acid solution (0.02N) to do the titration. It would be possible to use a stronger acid of known strength and dilute with demin water. This is the time honoured wet method and it works, though it takes a little practise. There is a very nice 10 ml burette on eBay.

Back to your problem. Have you changed the dropper bottle? It is possible that the drop of acid is not the same volume. This is why I do not like these test kits. In theory the drop should be about 0.05 ml or 20 drops per ml. However this is not a given. I would check the number of drops per ml if you can between the old and the new kit. It is possible that there is a significant difference. If the old bottle is empty a check with water should give some clue as to how much is one drop.

If Salifert have changed the acid concentration then I would have thought that this would have been made clear in the instructions. If they screwed up the in the production then I rest my case. If you can I would check the strength of the acid titrant; easy to say but perhaps not so easy for you to do. If your Salifert kit has a phenolphthalein indicator I could give you a method.

User avatar
Eric
Even further under the Table
Posts: 2873
Joined: Fri Mar 13, 2009 1:18 am
Location: Sunderland.

Re: Salifert Kit Confusion

Post by Eric » Tue Nov 14, 2017 8:43 pm

Carnot wrote:
Tue Nov 14, 2017 5:45 pm
This is my opinion , but no self respected water chemist would rely on a Salifert or any other drop test kit (Palintest included) for accuracy. Personally I would not waste my money. The best option would be to buy a 10 ml auto zeroing burette and some methyl orange indicator. You will then need a standardised acid solution (0.02N) to do the titration. It would be possible to use a stronger acid of known strength and dilute with demin water. This is the time honoured wet method and it works, though it takes a little practise. There is a very nice 10 ml burette on eBay.

Back to your problem. Have you changed the dropper bottle? It is possible that the drop of acid is not the same volume. This is why I do not like these test kits. In theory the drop should be about 0.05 ml or 20 drops per ml. However this is not a given. I would check the number of drops per ml if you can between the old and the new kit. It is possible that there is a significant difference. If the old bottle is empty a check with water should give some clue as to how much is one drop.

If Salifert have changed the acid concentration then I would have thought that this would have been made clear in the instructions. If they screwed up the in the production then I rest my case. If you can I would check the strength of the acid titrant; easy to say but perhaps not so easy for you to do. If your Salifert kit has a phenolphthalein indicator I could give you a method.
An interesting and, in some respects, a valid posting. I'm content with every self respecting water chemist not using a Salifert kit, but this is a brewer's forum and many self respecting and competent brewers know it is adequate for their purpose. While the Salifert is a drop test kit, you've obviously not used one for the kit uses not a dropper bottle for titration, but a 1 ml graduated syringe. OK, not a burette, but the vast majority of us don't need that for our task.

Is it worth the money? The OP assumed his water's alkalinity is constant. After adding the usual quantity of acid a Salifert test showed there was no alkalinity remaining to wonder if the acid he has bought is stronger than the previous batch. He asks for assistance on JBK and gets a full answer. I think that proves the worth of purchasing a kit that will do such a test for 10 pence.

It is true that the kit is not a precision piece of equipment, what could one expect for seven or eight quid? But don't waste your money, instead please purchase one which I'll refund when you publish the amount of it's deviation between 10 and 300mg/l alkalinity as CaCO3. Then both we, and others, would be a little wiser on this matter.

MyQul, I've found AMS/CRS from Murphy's, Brewpaks and the Malt Miller to have been consistent for all practical brewing purposes for all the time I've used it.
Without patience, life becomes difficult and the sooner it's finished, the better.

MyQul

Re: Salifert Kit Confusion

Post by MyQul » Tue Nov 14, 2017 9:49 pm

@carnot I find water chemisty difficult enough, so as long as I'm in the ball park (normally anything below 50 ppm alkalinity as I mosty make pale ales and I dont need to bother treating my water for dark beers anyway as I'm happy with the results) I'm happy enough. So I dont think I would find myself going down this methyl orange route.

I think you may have misundestood what I was asking. It's not the salifert test kit which I'm questioning but the AMS/CRS acid

@eric Thanks for the suggestions of where to get more acid. I bough 2x250ml bottles from HBC. The last 250ml bottle lasted me at least 18 months so I wont be requiring any acid for quite a while. But I'lle keep your suggestions in mind

User avatar
Eric
Even further under the Table
Posts: 2873
Joined: Fri Mar 13, 2009 1:18 am
Location: Sunderland.

Re: Salifert Kit Confusion

Post by Eric » Tue Nov 14, 2017 11:41 pm

MyQul, just to confirm, the acid you bought appeared to be that by BrewPaks. It is sold by many/most homebrew shops.
I have AMS but mostly use sulphuric and hydrochloric acids separately or collectively for brewing, but find them rarely, if ever, the advised strength which is where the Salifert kit is most valuable.

There are acids with specific molar values which are accurate intended for use by chemists but are relatively expensive for our cause and not necessarily food grade. I have accasionally used AMS for this type of work because it has proven to be consistent.
Without patience, life becomes difficult and the sooner it's finished, the better.

User avatar
MashTim
Piss Artist
Posts: 110
Joined: Wed May 29, 2013 9:44 pm

Salifert Kit Confusion

Post by MashTim » Wed Nov 15, 2017 11:14 am

I used to use the salifert kit, but recently splashed out on the Hanna Alkalinity gadget as my water definitely changes with the season and I need to test more than just brew water.

One thing I noticed is that that Hanna state that the water should not contain chlorine otherwise there may be false readings (you have to remember that Salifert was also designed for aquarium water).

So I ran a few test and discovered that between my pure tap water, filtered tap water and dechlorinated tap water that there was a 50ppm difference (range 225-275 this time of year) so I used the average ppm as the result. I used Campden powder to dechlorinate the tap water.

So bear in mind that chlorine may also be affecting he readings.

MyQul

Re: Salifert Kit Confusion

Post by MyQul » Wed Nov 15, 2017 9:53 pm

@eric What I recieved was not the same as in the picture. On the bottle is what appears to be a 'back' label with some instructions but no 'front' label the kind of thing that would normally have the manufacturers name/logo on it. So it doesnt actually state who made this CRS/AMS

@MashTim I normally treat my water with campden (although I'm not sure it needs it as I've forgotten to do it more than once and it does't seem to have made any difference)but usually after I've treated with acid. Perhaps I should try swapping and add the campden after instead to see if it makes any difference

User avatar
Kev888
So far gone I'm on the way back again!
Posts: 7701
Joined: Fri Mar 19, 2010 6:22 pm
Location: Derbyshire, UK

Re: Salifert Kit Confusion

Post by Kev888 » Thu Nov 16, 2017 2:45 pm

I'd assumed the item pictured was the one you received. CRS/AMS is normally consistent, but if it is not (necessarily) from the usual supplier then my opinion on the most likely cause may just have changed!

It is rare for manufacturers not to advertise on their own retail products. I'd guess the retailer may be buying the same stuff in bulk and splitting, but they could be mixing their own or getting it from elsewhere (it is just a blend of two acids) in which case it could be quite different - intentionally or otherwise.

But before pointing the finger at the acid you need to know alkalinity before and after treating, otherwise there are two unknowns and we are just guessing on which is unexpected. The salifert kit is normally very reliable and correlates well with professional analysis, but it is frustrating that they don't now always include the check solution - there are occasional issues (usually user error) and this was a simple way to verify all was well.
Kev

MyQul

Re: Salifert Kit Confusion

Post by MyQul » Thu Nov 16, 2017 8:10 pm

Kev888 wrote:
Thu Nov 16, 2017 2:45 pm
I'd assumed the item pictured was the one you received. CRS/AMS is normally consistent, but if it is not (necessarily) from the usual supplier then my opinion on the most likely cause may just have changed!

It is rare for manufacturers not to advertise on their own retail products. I'd guess the retailer may be buying the same stuff in bulk and splitting, but they could be mixing their own or getting it from elsewhere (it is just a blend of two acids) in which case it could be quite different - intentionally or otherwise.

But before pointing the finger at the acid you need to know alkalinity before and after treating, otherwise there are two unknowns and we are just guessing on which is unexpected. The salifert kit is normally very reliable and correlates well with professional analysis, but it is frustrating that they don't now always include the check solution - there are occasional issues (usually user error) and this was a simple way to verify all was well.
My salifert kit has the check solution but I'm not quite sure how you use it. Do you (or anyone else for that matter) know and can clue me in?

Post Reply