If minerals added to sparge water, do you still need to acidify when brewing a stout?

[Rob2010SS]

As the title reads - if all the brewing salts are added to your sparge water, do you need to acidify it as well with an acid if you're brewing a stout? I typically haven't but I think I pulled a bit of astringency on my Imperial stout and to me, this is the only place it could have come from... My baking soda was added to mash only so I know it wasn't that.

 

[mabrungard]

NOPE! Adding all your salts to the sparging water does not negate the need to acidify your sparging water...assuming that your tap water has significant alkalinity.

The acidifying effect of Ca and Mg cations is dependent upon sufficient contact time with the phytin from the malt. That creates the acid that lowers mash pH.

When you're sparging, the sparging water is in contact with phytins for only moment before those first runnings are gone from the mash and are replaced by the weak sparging water and newly leached malt sugars. There aren't many phytins left in that diluted wort to react with the Ca and Mg. So the whole effect is just thrown out the door.

A brewer has to get Ca and Mg in contact with the majority of the malt phytins within the mash in order to maximize the pH lowering effect of the Kolbach effect.

There aren't short cuts or end arounds on this issue.

 

[Rob2010SS]

NOPE! Adding all your salts to the sparging water does not negate the need to acidify your sparging water...assuming that your tap water has significant alkalinity.

The acidifying effect of Ca and Mg cations is dependent upon sufficient contact time with the phytin from the malt. That creates the acid that lowers mash pH.

When you're sparging, the sparging water is in contact with phytins for only moment before those first runnings are gone from the mash and are replaced by the weak sparging water and newly leached malt sugars. There aren't many phytins left in that diluted wort to react with the Ca and Mg. So the whole effect is just thrown out the door.

A brewer has to get Ca and Mg in contact with the majority of the malt phytins within the mash in order to maximize the pH lowering effect of the Kolbach effect.

There aren't short cuts or end arounds on this issue.

You meant to say yes right? I should have acidified sparge, correct?

 

[mabrungard]

YES, you do need to acidify sparging water if the raw water has much alkalinity.

 

[tracer bullet]

There aren't many phytins left in that diluted wort to react with the Ca and Mg. So the whole effect is just thrown out the door.

So, does this mean that there's no real need to put minerals (i.e. CaCl2, MgSO4, etc.) in the sparge water? Just acidify it, and skip the rest?

I've always added these but if it's not affecting much, I'll happily quit bothering with anything other than acidifying it.

Note for OP Rob - Bru'n Water has a nice tab for this, you can enter your water profile, the sparge pH you'd like to have, your acid source etc. and it'll give you an amount to use per gallon.

Note for Martin if reading - If I download Bru'n water right now, then open it in Excel, it tells me there's a circular reference issue and starts drawing arrows all over the place (trying to indicate where it is, but it's pointing to blocked out cells).

 

[CascadesBrewer]

Note for Martin if reading - If I download Bru'n water right now, then open it in Excel, it tells me there's a circular reference issue and starts drawing arrows all over the place (trying to indicate where it is, but it's pointing to blocked out cells).

It is annoying because I have to change this setting every once and a while. I have Excel 2016. File > Options (at the bottle left) > Formulas > check the "Enable iterative calculations" box.

I've always added these but if it's not affecting much, I'll happily quit bothering with anything other than acidifying it.

It does not look like it is in the free version, but in the paid version there is an option on the Water Adjustment to add all water mineral additions to the mash. The total amount of minerals added will have some impact on the final beer, even if they are not in the mash. I normally do full volume BIAB mashes, but if I sparge with a few gallons I use this option. This is mostly so I don't have to measure out additions twice, and usually a little more Calcium in my mash helps to bring my mash pH into range with less acid.

 

[Rob2010SS]

YES, you do need to acidify sparging water if the raw water has much alkalinity.

I use all RO water. Generally speaking, does RO water have a lot of alkalinity?

 

[IslandLizard]

Generally speaking, does RO water have a lot of alkalinity?

It does not. Mineral content of RO water is close to zero.*

Alkalinity is a result of certain minerals being present. Mineral content is easy to check with a (cheap, $12-20) TDS meter.
Any reading under 10 ppm can be ignored for brewing.

* That is, if the RO membrane and other filters all work as they should, and the flow rate is properly adjusted to your input water.

 

[Rob2010SS]

It does not. Mineral content of RO water is close to zero.*

Alkalinity is a result of certain minerals being present. Mineral content is easy to check with a (cheap, $12-20) TDS meter.
Any reading under 10 ppm can be ignored for brewing.

* That is, if the RO membrane and other filters all work as they should, and the flow rate is properly adjusted to your input water.

So I have a TDS meter built into the output line on the RO system and it read anywhere from 8-12 while collecting the water for this batch. The input water was reading around 530ish.

Thoughts?

 

[marc1]

So I have a TDS meter built into the output line on the RO system and it read anywhere from 8-12 while collecting the water for this batch. The input water was reading around 530ish.

Thoughts?

I wouldn't worry about it. Looks good to me.

 

[Rob2010SS]

I wouldn't worry about it. Looks good to me.

So then does it still stand that I should be acidifying sparge water?

 

[marc1]

So then does it still stand that I should be acidifying sparge water?

It doesn't have any alkalinity that needs to be neutralized because it's RO. I would not acidify.

If you did, it would take very little acid. Have you typically been using a lot of acid to acidify the sparge using this RO water? If that's the case, something is off somewhere that requires troubleshooting.

 

[Rob2010SS]

I have not been acidifying to this point. I picked up some astringency on my latest imp. stout and I was thinking this had to be where it was coming from. It was not there during the mash and to be honest, it wasn't there during the boil either though so maybe this isn't where it came from. Just not sure where it would have come from otherwise....

 

[IslandLizard]

Should we presume you're fly sparging?

Why would you want to add all your minerals to the sparge water, and not to the mash or at least split them between the two? Just don't add bicarbonates/carbonates to your sparge water.
If you want to mash without adding minerals, add the minerals to either the kettle, the chilled wort, or beer, after fermentation, or to any combination of them.

Have you measured the pH of your sparge runnings? Or better yet, scoop some grist out of the top 3rd of your mash tun toward the end of the sparge and take a pH reading.

I don't think one can taste astringency in sweet wort, but you may at the end of the sparge runnings.

 

[Rob2010SS]

Quick rundown of my process...

I collect 20 gallons of RO water in my HLT.
I add all of the minerals for mash and sparge water to that volume.
I heat that water to roughly 6 degrees over my strike temp.
Transfer my desired mash volume to MLT.
I mix in my desired amount of baking soda/pickling lime with the grains before dough in.

Once I add the grains to the MLT, I add whatever amount of cool water necessary to get my HLT back up to 17 gallons (this is where the HERMS coil is completely covered).

I then add back more minerals to the sparge water based on how much water I added back in. So if I added 6 gallons of water to the HLT, I'll take the per gallon numbers from Bru'n Water, do the math and add that to HLT.

In answer to your question, yes, I fly sparge. On this particular batch, took me approx. 90-95 minutes to complete the sparge.

I have not checked the pH of the sparge runnings, only the mash. Mash pH here was 5.45.

I can say that during the mash, the wort did not taste astringent.
During the boil, it did not taste astringent. I can say that the first imperial stout I did, I added baking soda to the sparge water by mistake. I can verify that you CAN taste astringency during the boil.

However, in this case, I didn't pick it up until after fermentation, which I thought was weird.

 

[Jag75]

Don't know if you had your water checked but it may be great for brewing dark beers. I use tap water for all my porters and stouts. Light beers I use RO along with Bru n Water.

 

[Rob2010SS]

Don't know if you had your water checked but it may be great for brewing dark beers. I use tap water for all my porters and stouts. Light beers I use RO along with Bru n Water.

I haven't had it checked actually. Might do it one day. We have a water softener so not sure if that makes our water good for lighter beers or darker.

 

[ScrewyBrewer]

I would hook up the RO filter before the water goes through the water softener.