Saturday, January 7, 2012

How to Clone Mineral Water

Cloning popular brands of mineral water is now simpler then ever before with the updated version of the mineral water calculator!

When I blogged about DIY mineral water last year it was mainly a theoretical exercise since I didn’t have the required salts at hand. My experience was limited to adding some baking soda (sodium bicarbonate) to water before carbonation. Luckily Paul Hinrichs tested the calculator! In the meantime I have purchased the required salts and with several kilograms in total I’m probably well stocked for the next decade! Based on the output from the calculator, I mixed the salts required to clone San Pellegrino, added water and carbonated the mixture. And the good news is that it works! The water tastes great and I’ve been enjoying cloned mineral waters every day now for the last couple of weeks.

Some changes have been made to the mineral water calculator (Excel file for download: mineral_water_calculator_v4.xlsx, 36 kB) since I last posted:

a simpler worksheet more suitable for printing has been added
more mineral waters have been added to the database, covering TDS (total dissolved solids) levels all the way up to more than 4000 mg/L
potassium bicarbonate, magnesium chloride and calcium nitrate are made optional and can be left out if desired (it’s still a little unclear to me to what extent these can be detected at the typical levels found in mineral waters)
one can now chose between using either hydroxides or carbonates of calcium and magnesium, depending on availability (it should be noted however that some waters high in bicarbonate require the use of the hydroxides)
A spoon full of mineral salts is required for the preparation of 1 liter of San Pellegrino mineral water.

Instructions for how to prepare the mixture of salts
Start by chosing the mineral water you want to clone from the drop down list. My advice would be not to start with the waters having very high levels of total dissolved solids (TDS) (except Kessel and Vichy Saint-Yorre since sodium bicarbonate dissolves easily). Aim for a TDS in the range 200-1500 mg/L (the list of all mineral waters in the rightmost worksheet is viewable and sortable). At the lower end you may not detect much mineral taste at all. At the higher end the mineral taste becomes quite pronounced. You can click the check boxes to include/exclude some salts. If known enter the composition of your tap water (your local water company should be able to give you these figures). I suggest that you weigh out the salts for 10 or even 100 liters, otherwise the amounts of salts will be in the low milligram or microgram range, requiring expensive lab scales. Mix the salts well. It may be god to start by mixing the salts present in the lowest concentrations first to ensure a homogeneous mixture.

How to make a cloned mineral water
Weigh out the approximate amount of salt (prepared as described above) needed for the amount of water that your carbonation vessel holds. At this point it’s doesn’t need to be very accurate, so if you have weighed it once you can simply need to remember which spoon you used and the size of the heap. Note that the different mineral salts vary greatly in density, so you should calibrate the heap used for each mineral salt mixture. Add the salt to the carbonation vessel and fill it up to the mark with water. The water will now turn opaque and whitish as the salts are suspended in the water (see picture above). Carbonate carefully and, depending on whether the water is high in carbonation and/or bicarbonate, try to hold the carbonation pressure for a couple of seconds extra before letting the pressure out. This allows a little more carbon dioxide to dissolve. Screw on the cap immediately to prevent the carbon dioxide from escaping. In some cases it may be necessary to repeat the carbonation step after some hours. Once the salts have dissolved (i.e. the water becomes clear) you can enjoy your very own home-made mineral water!
Several of the mineral salts have are not soluble in tap water, hence the opaque look to the left. After carbonation however they dissolve rapidly.

So far I’ve made up the salt mixtures for San Pellegrino (total dissolved solids, TDS: 1109 mg/L) and Gerolsteiner (TDS: 2488 mg/L). The first works like a charm, even when all salts are added simultaneously. This is possibly due to the high amount of sulfates which seem to dissolve more easily. Gerolsteiner is more tricky, partly due to the high TDS and the low amount of sulfate. I made it using carbonates instead of hydroxides, hoping that this would require addition of less carbon dioxide to neutralize the base. But after two days and 2-3 extra additions of carbon dioxide the salts had still not dissolved completely and this puzzles me. I certainly need to repeat this experiment. Darcy O’Neil states in Fix the pumps that the order of addition does matter. I’m not quite sure if that really is the case as most of the salts have a very low water solubility to start with, and the carbonic acid is the reason they dissolve. But maybe there is something I’m overlooking here? It could be that Gerolsteiner is easier to do with hydroxides, but Paul Hinrichs also had some trouble getting all the salts to dissolve for Gerolsteiner.

Some of the salts may be tricky to obtain, but the synonyms and links to Amazon below may be of some help:

CaSO4·0.5H2O = Plaster of Paris (check availability from Amazon)
MgSO4·7H2O = Epsom salt (check availability from Amazon)
CaCO3 = Chalk (check availability from Amazon)
NaHCO3 = Baking soda
NaCl = Table salt
Mg(OH)2 = Milk of magnesia (check availability from Amazon)
Ca(OH)2 = Slaked lime, pickling lime, CAL (check availability from Amazon)

Before you head of to Amazon or some other place to order salts I should probably add some words of warning: make sure that the source you find is suitable for consumption! Some technical qualities of mineral salts may not be intended for food use, for instance due to the presence of heavy metals or other contaminants.

Note that some of the salts are available with varying amounts of crystal water. If you use other salts than those specified (i.e. anhydrous salts or salts with more crystal water) the molecular weights in the spreadsheet need to be adjusted for this. I guess that if you are familiar with the concept of crystal water, you’ll easily figure out the correct molecular weight and how to update the calculator according to the specific salts you chose to use.

Screen shot of the simple version, best suited for printing (click screen shot to download mineral_water_calculator_v4.xlsx):
Mineral waters included in the database that comes with the calculator: Acqua Panna, Antipodes, Apollinaris, Aquarel Birken, Badoit, Borsec, Calistoga, Carola, Contrex, Dorna, Evian, Farris, Fiuggi, Gerolsteiner, Harghita, Hassia sprudel, Henniez, Kessel, Mountain Valley Spring, Neuselters, Perrier, Rosbacher Klassich, Salvus, San Benedetto, San Narciso, San Pellegrino, Selters, Tesanjski Dijamant, Ty Nant, Vichy Saint-Yorre, Vittel, Volvic, Voss, Waiwera. And you can easily add data for other mineral waters. The websites and have data for several hundred waters available. And if you have a bottle of your favourite mineral water at hand you only need to check the label to find the required input for the calculator.