Epson Salts

[Edgard]

Hello,

The Epson Salts we buy in the shops or on line state that they are not pure MgSO4.

Some state it is 9.7% Magnesium and 12.9$ S.

So there is 77% other stuff in there and which is not listed.

So when we use our Brewing SW or Excel table to define water additions and when these tools ask for 'Epson Salt' does this take into account that 77% is not MgsO4?

Maybe 100% pure does not exist as it binds with water?

So if my brewing tool asks for 5 grams in the mash, so I add 5 gram of the stuff I buy on line?

Or...

I need to multiply this by 4 or so and add 20 grams?

Thanks for any insight in this.

Edgard

 

[RPh_Guy]

Hey Edgard, welcome to HBT!

Salts often incorporate some amount of water molecules into their crystalline structure. In the case of magnesium sulfate, that's typically about 7 water molecules per each mole.

Magnesium: 24.305 g/mol
Magnesium sulfate heptahydrate: 246.48 g/mol

24.305/246.48 = 0.098608 = 9.86%

So if my brewing tool asks for 5 grams in the mash, so I add 5 gram of the stuff I buy on line?

Yep, you can probably just use what the software suggests. You might want to double check the math to be sure, but accidentally using half the recommended magnesium sulfate wouldn't hurt anything.

Hope that makes sense.
Cheers,
Adam

 

[bkboiler]

You can also buy USP Epsom salt at a drug store. If you read about USP it's basically a kind of pharmaceutical standard so the requirement for accurate reporting of the content is more strict than for foodstuffs.

Watch out for those Epson salts...they are cheap at first but kill you on the refills.

 

[day_trippr]

fwiw, you can get 2 pound bags of unscented USP epsom salt at Amazon for modest cost and have many home brewing lifetimes worth

Cheers!

 

[BigEd]

Hello,

The Epson Salts we buy in the shops or on line state that they are not pure MgSO4.

Some state it is 9.7% Magnesium and 12.9$ S.

So there is 77% other stuff in there and which is not listed.

So when we use our Brewing SW or Excel table to define water additions and when these tools ask for 'Epson Salt' does this take into account that 77% is not MgsO4?

Maybe 100% pure does not exist as it binds with water?

So if my brewing tool asks for 5 grams in the mash, so I add 5 gram of the stuff I buy on line?

Or...

I need to multiply this by 4 or so and add 20 grams?

Thanks for any insight in this.

Edgard

You only need tiny amounts of Mg+ in brewing water. How many ppm are you targeting? Single digit ppm is usually enough. If your source water has even 3-4 ppm that plus what is already in the malt should be more than plenty.

 

[day_trippr]

^agreed^
It's DI and RO water that might want a touch. I aim for 8ppm...

Cheers!

 

[RPh_Guy]

You only need tiny amounts of Mg+ in brewing water.

FYI magnesium has a +2 charge, so you should write it as Mg++

Magnesium affects flavors and some people may want it above 10ppm in certain styles, more than what's needed.

 

[Clyde McCoy]

Unless your water has <5 ppm Mg++ I wouldn't use Epsom. Use calcium sulfate and calcium chloride.

This is the the best online guide to brewing liquor:

https://www.brunwater.com/water-knowledge

 

[mabrungard]

Using epsom salt is a good thing in brewing, but do avoid overdoing the magnesium content. If your water already has more than about 20 ppm Mg, do think twice before adding. But the important thing is Mg has it's place in brewing when your beer is intended to be bitter. It helps.

For anyone buying epsom salt at the grocery or drug store, make sure that it's UNSCENTED and food-grade. The other stuff does exist and it'll ruin your beer.

 

[CascadesBrewer]

fwiw, you can get 2 pound bags of unscented USP epsom salt at Amazon for modest cost and have many home brewing lifetimes worth

Yep, one of these days I need to take in some bags to my homebrew club...or maybe soak my feet after a brew day? I got a 3 lb bag at Walmart a while back. (Though honestly, I could just not use it at all myself...I use it mostly because my tap calcium is kinda high and makes my profile numbers look better on paper...and I have seen some recommendation for levels around 30 ppm for dark beers.)

For anyone buying epsom salt at the grocery or drug store, make sure that it's UNSCENTED and food-grade. The other stuff does exist and it'll ruin your beer.

What? You don't like that lavender and rose petal flavor in your beers???

 

[mabrungard]

and I have seen some recommendation for levels around 30 ppm for dark beers.)

I haven't tried boosting Mg that high in a roasty beer since that may enhance a bitter perception and I'm concerned that it may be too much with the roast. But I'm hoping that others will comment if they've tried that.

Regarding the lavender and rose...you could be a trendsetter!

 

[CascadesBrewer]

I haven't tried boosting Mg that high in a roasty beer since that may enhance a bitter perception and I'm concerned that it may be too much with the roast. But I'm hoping that others will comment if they've tried that.

It is based on the following from "Water" Palmer/Kaminski:

"The the best of our knowledge, no studies have been done to determine this level, but one of the authors (C. Kaminski), swears by adding small additions or Epsom salt to dark beers, such as porter, to achieve a minimum of 30 ppm Mg in the water going into the mash." (pg 148)

 

[bkboiler]

Lol about the scented...
I'm pretty sure so looked when I bought it, but I'm gonna go look again before I use it!

 

[mabrungard]

It is based on the following from "Water" Palmer/Kaminski:

"The the best of our knowledge, no studies have been done to determine this level, but one of the authors (C. Kaminski), swears by adding small additions or Epsom salt to dark beers, such as porter, to achieve a minimum of 30 ppm Mg in the water going into the mash." (pg 148)

Hmm? I would have seen that when editing that book, but clearly I didn't retain it. I'm not a personal fan of brewing with that much magnesium, but let's hope that more respond with their findings.

Thanks

 

[Carolina_Matt]

I initially only bought Calcium Chloride, Gypsum and Lactic Acid. I used it sparingly with EZ_Water, but didn't quite know what I was doing.

I finally got around to reading Homebrew Beyond the Basics by Mike Karnowski, and he recommends at least 10 ppm of Magnesium because it helps the yeast. Charlotte NC tap water only has 2 ppm (according to their website - I have not had it tested myself). I bought a pound of Epsom Salt this weekend at Walmart and I think it was 88 cents.

Without Epsom Salt, it was hard to hit my CL and SO4 targets without going overboard on CA. With Epsom Salt, I was able to get close to Karnowski's range for hop-oriented beer.

I actually used more Epsom than anything else. 4g Epsom, 3.5g Gypsum, 2.5g CaCl2, and 2ml of Lactic Acid. I'll know in 2 weeks if it ruined the beer.

 

[VikeMan]

I finally got around to reading Homebrew Beyond the Basics by Mike Karnowski, and he recommends at least 10 ppm of Magnesium because it helps the yeast.

The malt provides more Mg than the yeast need, so you don't need to add any unless you're using it to adjust pH or add flavor.

 

[BrewnWKopperKat]

I finally got around to reading Homebrew Beyond the Basics by Mike Karnowski

The "just two" profiles (hoppy / malty) profiles in Homebrew Beyond the Basics are a 'dirt simple' way to get started with brewing salts. After that, it's season to taste and fine tune for that "unknown" amount of minerals in the malt.

Brewing Better Beer (Strong) has a similar simple approach. I may queue up a couple of batches where I vary only their recommended brewing salts.

Skim readers: take note that Karnowski wrote Homebrew Beyond the Basics and Kaminski co-authored Water.

 

[SpeedYellow]

Also remember that epsom salt does hold water, like CaCl. I bought some USP epsom salt, weighed a handful, baked it in the toaster oven for 20-30 minutes, and it came out like 12% lighter (about the same as when I did this to some CaCl). Goes from shiny and glassy to matte white.

So like CaCl, you should bake your MgSO4.

 

[RPh_Guy]

Also remember that epsom salt does hold water, like CaCl. I bought some USP epsom salt, weighed a handful, baked it in the toaster oven for 20-30 minutes, and it came out like 12% lighter (about the same as when I did this to some CaCl). Goes from shiny and glassy to matte white.

So like CaCl, you should bake your MgSO4.

No, you should not bake it. The heptahydrate state (epsom salt) is already fully hydrated and therefore not hygroscopic.

 

[Dancy]

For anyone buying epsom salt at the grocery or drug store, make sure that it's UNSCENTED and food-grade. The other stuff does exist and it'll ruin your beer.

 

[Dancy]

I just purchased some Epsom salts at my local large grocery store. The label does not state “food grade” but it does give directions to mix with water as a laxative so I assume it is food grade.

 

[mabrungard]

Yes, something that is listed for laxative use is probably food—safe.

 

[stevehaun]

And if you push your magnesium levels high enough your beer will double as a laxative!

 

[Dancy]

And if you push your magnesium levels high enough your beer will double as a laxative!

I was gonna make a joke about that but decided to see how long it would take for someone else to do that