Water treatment

[phil]

Long term members will have heard me bleating about this sort of thing before.

I have finally found an office environment where I'm allowed to brew my own coffee. A water boiler is provided, giving a constant supply of brewing water. Other electrical equipment is not allowed - so no kettles, electric vac pots or electric grinders. Just me, my trusty Zass 169 hand mill and a press pot.

Nonetheless at first I thought I'd died and gone to heaven. Real homeroast in the office! Woo hoo! Then the reality started to dawn on my taste buds.

My coffee doesn't taste as good as it should. Even grinding fairly coarsely and reducing brewing time I taste the flavour of rather over-extracted coffee.

The culprit? Gotta be soft water. After all, my client obviously doesn't want their boiler scaling up, eh?

So I need a source of calcium to add to the brew. Sulphate I suppose, as a powdered form and food grade. Powdered gypsum in fact, the sort of stuff I used to use for home brewing in the 70s (I was a geek about that too ). The trouble is, you can get this sort of stuff by mail order but at 85p per 100g it's not really the sort of thing you want to be buying 1 of - it's kinda embarassing. Homebrewing shops seemed to have died out.

Any alternative ideas?

[RobC]

Ouch! Just fell off my chair. Phil, are you saying that Hard Water improves coffee taste?? Pretty new on me that one, my only previous concern is the effects limescale has on hot beverage equipment, particularly HX espresso machines - so making water soft is a big mission on cutting service call outs. I know from experience that softening water improves that taste of tea (hard water customers have found that tea brewed from their filtered equipment receives great accolade from their own customers when compared to tea brewed at home with a kettle) but I had no idea it could affect the taste of coffee adversly.

I would be interested to hear any other comments on this topic.

Off on a bit of a tangent, but does anyone know the relative advantages/disadvantages of using bottled mineral water rather then filtered tap water or raw tap water in hard water areas.? I am sure I read a reason for not using bottled water (other then cost) but I can't remember why. Obviously this is for hand filled equipment not mains water fed equipment.

[phil]

Re the taste - go off and read the water FAQ (URL can be found elsewhere on TMC and also via Google). This info is established coffee lore (my memory tells me Jim Schulman is responsible for this, and I personally respect his views on matters coffee above those of just about anyone else). It's not something from my fevered imagination.

Alternatively, just make up two press pots side by side - one with soft filtered water (preferably RO so you get the extreme case), the other with hard water (but not the muck out of the tap - try one of the commercial bottled waters with about 50 ppm Ca). If you can't tell the difference then your taste buds are dead. The harder water version brings out the more delicate flavours and gives an effeect which I can only describe by analogy as being like going from a press pot to a vac pot (but perhaps not so extreme - this is an analogy only).

IMO the issue with espresso machines is striking a balance between the detrimental effects of scale on the mechanism and the detrimental effects of over-soft water on the brew.

[Ian]

There is a home-brew shop about a mile from me which I'll be passing on Saturday and they have the stuff in stock http://www.the-home-brew-shop.co.uk/item891.htm

I've been meaning to send you some greens for a while in lieu of a subscription/cash donation so I could combine both in one parcel if you like. PM or email me your address if you're interested.

Cheers

[phil]

Ian

I'm really grateful for the offer. Email on its way

Cheers

Phil

[Steve]

So come on then any results yet

Steve

[phil]

When I get some gypsum I'll let you know. Don't have any yet.

[tisri]

I can back up the comments about RO water. I have a softener and RO filter at home and for a long time used exclusively RO water in the kettle and my Gaggia machine. As it happens it was one of Phil's previous comments that led me to try regular soft water in the Gaggia and the difference was quite surprising. Since London's water is spectacularly hard I don't want to subject my boilers to the ravages of so much calcium but I'm becoming tempted to go back to using RO water (to take the fluoride out, among other impurities) but then to add back some calcium salts to improve the coffee.

[phil]

Well, maybe that's a bit ambitious for a title.

Anyway, thanks to the kind help of two other TMCers (Steve and Ian) I now have enough gypsum to brew (by my calculations) roughly 80 pots of coffee. That should be enough to form an opinion, don't you think?

Right, I just brewed my first pot at work with the benefit of water treatment. I was totally unscientific, I admit. I took a coffee I'd never tasted before and brewed a pot. However, in my defence I think that the over-extracted characteristics of the previous brews were so obvious that I should know whether the experiment was a success.

Initial conclusion:

YUP. Much better.

I can now begin to taste the subtle flavours that make us all coffee afficionados, instead of just a full-on overextracted "coffee" flavour.

OK, I'm never going to get the clarity and delicacy I get from my Cona when I brew in a cheap Bodum press pot, but in all honesty the difference was startling. I'm confident that I can say that even though I've never tasted this particular coffee - I have after all tasted many similar ones.

Technical details:

5g gypsum (calcium sulphate) in an 8-cup press pot (approx 900 mls water).

I'll keep trying ths, and I may consider other additional water treatment ideas I remember from my home-brewing days.

Warmest thanks to Ian and Steve for supplying the gypsum for this experiment. Thanks, guys!