Gypsum

I guess this would be a technical thread, but I have a question about it. My latest recipe for a Palilalia IPA called for 2 tsp of gypsum, which I bought and used and the brew turned out great
So now I'm wondering, what is gypsum exactly used for? I guess it has something to do with 'hardening' the water, by adding some certain minerals to it, and making it apparently a little more sticky and thick. What is the actual benefit of this? Would I really be able to tell the difference if I hadn't used it? And when would gypsum be good to use for a brew?

bosox said:

I guess this would be a technical thread, but I have a question about it. My latest recipe for a Palilalia IPA called for 2 tsp of gypsum, which I bought and used and the brew turned out great
So now I'm wondering, what is gypsum exactly used for? I guess it has something to do with 'hardening' the water, by adding some certain minerals to it, and making it apparently a little more sticky and thick. What is the actual benefit of this? Would I really be able to tell the difference if I hadn't used it? And when would gypsum be good to use for a brew?

Click to expand...

The brew science forum has a ton of info on water chemistry, Gypsum raises the hardness and lowers the pH (raises acidity) of the water.

It gets fairly technical, so that is the short simple answer. Check the brew science threads, you'll find everything you want to know about water chemistry for brewing there.

There are also some great podcasts on the Brewing Network and Basic Brewing Radio.

Cheers,
BGB

There are several uses for gypsum (calcium sulfate) in brewing. It is used in calcium-deficient mashes to increase calcium content, which is crucial for proper enzymatic conversion. This also decreases residual alkalinity of the water somewhat.

It is used in the boil for taste perception. It does not thicken the water. Higher sulfate ion concentrations make the hop bitterness "pop," taste more crisp, especially when paired with lower chloride ion concentrations. I've never seen a scientific study on it, but it is well known that breweries use this technique, and I think many members here would vouch for it as well.

Proper calcium levels are also crucial to yeast metabolism.

bosox said:

Would I really be able to tell the difference if I hadn't used it? And when would gypsum be good to use for a brew?

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Good or bad, you would certainly notice a difference. Gypsum, though, is just one small aspect of a larger topic (Water conditioning) There are two ways to go. Experiment solely with gypsum and your own water (Could well work out fine) or get into the whole business of water reports, proper treatment per style etc. Either way, gypsum is one small aspect of a larger scheme.

Do what works for you now, and plan for greater things ahead.

I don't think I'm prepared to understand all the technicality of the issue haha, I spose then I should only add gypsum when it tells me to, and don't do anything on my own then, as I'm an English major and avoid science/math like the plague!

bosox said:

I don't think I'm prepared to understand all the technicality of the issue haha, I spose then I should only add gypsum when it tells me to, and don't do anything on my own then, as I'm an English major and avoid science/math like the plague!

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Student eh? Go and study, we'll suck you back into the obsession properly after you have your degree (Insert maniacal laugh .wav here)

I like greenbirds reply.
I also wouldn't trust a recipe that says to add 2 tsp gypsum without any knowledge of your water profile.

-a.

This is an old thread, but I wanted to try gypsum so I mixed a small amount in a half gallon of water. Did a taste test next to the same, untreated, water. Definitely made a difference, so I used it on my Sierra Nevada pale ale. Just kegged it but post mash taste tests show promise!

Gypsum is supposed to soften the water, but in my test the gypsum water tastes more mineral-y, which I think of as hard water. Meh.

kevreh said:

This is an old thread, but I wanted to try gypsum so I mixed a small amount in a half gallon of water. Did a taste test next to the same, untreated, water. Definitely made a difference, so I used it on my Sierra Nevada pale ale. Just kegged it but post mash taste tests show promise!

Gypsum is supposed to soften the water, but in my test the gypsum water tastes more mineral-y, which I think of as hard water. Meh.

Click to expand...

Well, you're adding hardness/minerals, so it makes sense that it'd taste more minerally.

kevreh said:

This is an old thread, but I wanted to try gypsum so I mixed a small amount in a half gallon of water. Did a taste test next to the same, untreated, water. Definitely made a difference, so I used it on my Sierra Nevada pale ale. Just kegged it but post mash taste tests show promise!

Gypsum is supposed to soften the water, but in my test the gypsum water tastes more mineral-y, which I think of as hard water. Meh.

Click to expand...

Do you have any idea what concentration of calcium and sulfate you are adding to that water? All things in moderation...if you added a significant concentration of those ions to the water then a minerally taste is probable. As pointed out above, gypsum hardens water. What resource told you it softened water?

mabrungard said:

Do you have any idea what concentration of calcium and sulfate you are adding to that water? All things in moderation...if you added a significant concentration of those ions to the water then a minerally taste is probable. As pointed out above, gypsum hardens water. What resource told you it softened water?

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Guess I read that somewhere or remember it wrong. Thanks for the clarification.

For my 5 gal batch I added about 1/3 teaspoon; very moderate. I'm glad to have Gypsum in my set of "tools" to get those pale ales that have a little more pop to the hop profile and slight hardness to the water profile.

Conversely, it would seem appropriate to use calcium chloride (or other) to soften the water for something like a German Heff. ?

Kevin

Again, adding CaCl doesn't soften the water. It reduces the Residual Alkalinity of the water which helps reduce mash pH. In my opinion, adding CaCl could be a preferred treatment for a beer that does not rely on hop bittering and flavor. But a caution is in order since overdosing with CaCl could present the same sort of minerally character, so remember: All things in Moderation!

I personally don't measure out mineral additions volumetrically since its inherently inaccurate due to variation in packing of the loose powders that some minerals are provided in. I guess its not such problem when dealing with more granular minerals, but I do prefer to weigh my additions. Weighing also provides a finer dosing capability if the scale is sensitive enough. I suggest getting a scale with 0.1 gram resolution if brewing in 10 gal or smaller batches.