‘Lightly Salted’ Beer
Friend (via Suse’s Mums group) and award-winning photographer Liam from Lightly Salted Photography has asked me to brew up a batch of theme beer for a studio launch, the theme being… ‘lightly salted’.
The initial concept was to be a coriander and salt beer, but I can’t stand coriander (thanks, genetics) so I suggested a salty chilli-lime affair.
Now, anyone currently jumping up and down screaming ‘Gose‘ can kindly sit back down as I point out that this will neither be soured, nor contain wheat (another genetic disposition, this time to phenols). It’s just going to be a slightly salty beer, probably based on an American IPA.
Deciding to do this was the easy part… the chemistry is actually a little bit more complicated. I needed to refer to my books on this one.
John Palmer (in How To Brew) recommends that Sodium be kept below 200ppm if it’s to NOT taste salty (preferred range 0-150ppm). A fellow brewer suggests that this upper limit is related to yeast osmotic stress more than anything, and recommends adding salts of this level post-fermentation. Makes sense.
John also recommends keeping Chloride below 300ppm to stop that ‘mediciny’ or ‘bleach’ taste (preferred range 0-250ppm).
The first question to ask is “what is my current water content?”. Thankfully we have (had?) nice, regular (5 yearly) water reports from SA Water, though their current website doesn’t provide much in the way of water quality data anymore, at least not with a few minutes of searching. Thankfully, I’ve saved the last few full reports, and will go by the 2004-2009 tables for my supply area (Anstey Hill… despite being very close to the Hope Valley reservoir, I’m uphill from it, so I get my water from further up). That data suggests that my water content includes:
|Sodium [Na]||71 mg/L|
|Cloride [Cl]||112 mg/L|
|Alkalinity as CaCO3||43 mg/L|
The alkalinity can be converted to CO3 by multiplying by 50/61, which makes it 35ppm (Note: g/L == ppm).
The next thing we need to know is by how much the concentration is increased by adding a gram of a certain salt. This page has the easiest table I could find (though it still uses gallons) in which a gram of salt X raises the concentration of ion Y by Zppm.
|1 gram of ... added to 1 gallon (3.78L)||raises the concentration of|
|NaCl||Na by 104ppm|
|Cl by 160ppm|
|NaHCO3 (baking soda)||Na by 72ppm|
|CO3 by 188ppm|
One should be careful with ‘bicarb soda’ which can be sold as ‘baking powder’ and ‘baking soda’… one is pure NaHCO3, the other typically includes Tartaric acid and a starch as well. The Tartaric would probably throw things out a bit, so I’ll source some pure bicarb soda. For the NaCl I’ll be sourcing Murray river pink salt – pink is the theme colour of ‘Lightly Salted’ so that works in nicely.
I played around with various combinations of these numbers, adding various quantities to my current water content, and settled on the mixture of 0.9g/gallon of NaCl with 1g/gallon of NaHCO3 (baking soda) which brings my salted water content up to
Now, this might seem a little random without context, so here are some examples of particularly ‘salty’ but ‘classic’ water styles (click to sort by column)
I’ll be trying out some sample rates on the weekend with commercial beers. For those purposes, I’ll need to use tiny amounts of salts. 1g/gallon converts to 0.1g/375mL quite nicely. For a full batch, 1g/gallon converts to 5.8g/22L. This is a job for the
cocainehops scales which have a resolution of 0.01g.
Next I’ll need to figure out the levels of chilli and lime. So far this is pretty fun. Updates to follow as things progress…
Update 1: A question has been raised about the ion content of Murray river pink salt and how that would affect my calculations. The Sunsalt website lists the various elements and those of interest here are:
Chloride Cl 60.3 %
Sodium Na 39.1 %
So it’s mainly table salt (99.4%). There’s also a lot of sulphate (3440ppm SO4 or 0.344%) which will mess the chloride around a bit, but we’ll see how it goes.
Update 2: The beer has been salted. We went through a few litres on quality control, so I had to change the quantities of salts to add. In the end I assumed about 16-17L remaining, so I’ve added 3g of the river salt and 3.5g of the bicarb, leaving the ability to add more if needed (good luck removing salt from beer after the fact). It tasted… lightly salted. Nice. The beer will be poured at the studio launch tomorrow night, so I’ll wait until then for final critique.
Update 3: All went well! The keg was set up behind a board with a tap poking through the Lightly Salted logo. After being chilled to settle at the studio and having a couple of hours on ice before everyone showed up, it poured bright and without excessive head. The aftertaste was spot on – just a little bit salty. Compliments were forthcoming on the night, with one person thinking that I ran a professional brewery called ‘Keg Beer’ and another person thinking we had Vale Ale on tap (the logos do look a bit similar – both sets of dots, and the IPA style was in line with Vale IPA).
The spiel on the board was written jointly by Liam and me:
India Pale Ale (IPA) lovingly crafted from Dr Jono Carroll’s blood, sweat, and tears (ingredients may vary – minimum 2% tears)
With more hops than you can poke a Nikon at and a dash of pink salt, pour yourself a one of a kind Lightly Salted beer!
In the end the keg lasted all of 3 hours, with many people going back for seconds/thirds/lots. It’s been a great experience having my own beer on tap at a professional function. Thank you Liam for the opportunity.