Bohemian Pilsner: Soft water and pH

[MrHadack]

I have extremely soft water where I live. It's essentially the exact same profile as Pilsen, Czech Republic. I plan to make a Bohemian Pilsner and have a malt bill of 90% Pilsner, 5% Light Munich, and 5% Carafoam.

According to the Bru'n Water spreadsheet (which has been 100% accurate for all my past batches) the pH of the mash would come in at 5.8 so I need to lower it. My first thought was to use 0.5ml lactic acid to lower the 5.5 gallons of mash water to pH 5.3.

My second though was to use 8oz acid malt. Since acid malt is pilsner malt treated with lactic acid, I can swap 8oz of the normal pilsner grain for 8oz of the acid malt, and not change my recipe formulation: 90% Pilsner (85% normal, and 5% acid malt), 5% Munich, and 5% carapils. Both methods get the pH to 5.3, and I match the Pilsen water profile exactly (as far as the graph is concerned anyway... )

My only question is whether acid malt, as opposed to a direct acid addition, will change the flavor of the beer in any way. Is one method approved over the other?

 

[Yankeehillbrewer]

I can't answer your question, but what about an Acid Rest?

 

[JonM]

The chemistry primer recommends that the total grist be 2-3% acid malt for beers like this, so it looks like you're in the ballpark.

 

[BigEd]

I have extremely soft water where I live. It's essentially the exact same profile as Pilsen, Czech Republic. I plan to make a Bohemian Pilsner and have a malt bill of 90% Pilsner, 5% Light Munich, and 5% Carafoam.

According to the Bru'n Water spreadsheet (which has been 100% accurate for all my past batches) the pH of the mash would come in at 5.8 so I need to lower it. My first thought was to use 0.5ml lactic acid to lower the 5.5 gallons of mash water to pH 5.3.

My second though was to use 8oz acid malt. Since acid malt is pilsner malt treated with lactic acid, I can swap 8oz of the normal pilsner grain for 8oz of the acid malt, and not change my recipe formulation: 90% Pilsner (85% normal, and 5% acid malt), 5% Munich, and 5% carapils. Both methods get the pH to 5.3, and I match the Pilsen water profile exactly (as far as the graph is concerned anyway... )

My only question is whether acid malt, as opposed to a direct acid addition, will change the flavor of the beer in any way. Is one method approved over the other?

You don't need or want to try to match exactly a Pilsen water profile. In addition to the pH you need to think about the mineral ion content since your water is probably low in Calcium, Ca+. Acid malt is just plain malt with acid sprayed on it. Adding acid will bring the pH down but you are still going to be deficient in Calcium content. An addition of Calcium Chloride to bring the Ca+ ppm up to ~75 may take care of both problems. Most of the surface water in southern New England is very soft and low in minerals. My water comes from the Providence reservoir supply and has similar numbers to yours. I have had very good success with a small Calcium Chloride addition for this beer style.

 

[MrHadack]

I can't answer your question, but what about an Acid Rest?

I did plan to do a triple decoction mash which included a 45 minute acid rest at 95F (which was the default that came up when I selected that style of mash in BeerSmith.) I just had no idea how much that would lower my pH. I'll do a little research on that but anything you can tell me would be great.

 

[MrHadack]

You don't need or want to try to match exactly a Pilsen water profile. In addition to the pH you need to think about the mineral ion content since your water is probably low in Calcium, Ca+. Acid malt is just plain malt with acid sprayed on it. Adding acid will bring the pH down but you are still going to be deficient in Calcium content. An addition of Calcium Chloride to bring the Ca+ ppm up to ~75 may take care of both problems. Most of the surface water in southern New England is very soft and low in minerals. My water comes from the Providence reservoir supply and has similar numbers to yours. I have had very good success with a small Calcium Chloride addition for this beer style.

Thanks for your input-- being from a similar region as I am I appreciate your experience with this.

I typically don't try to match water profiles. My standard practice is to bump up the calcium over 50ppm and then get the sulfate / chloride ratio and levels where it should be for the particular style I am brewing. After that, I just tweak things slightly until the predicted mash pH hits 5.3 or 5.4 and I am good to go. I typically never need to use acid except for the in the sparge water.

In this case, I am already at the Pilsen water profile so I thought why not go with it? As for the calcium, I read up on the brewing methods of Pilsner Urquell and the brewery says their source water only has 10ppm calcium. I did modify my water profile slightly to get it up to 11ppm. Is the principal concern here the health of the yeast? I am making a pretty good starter for it (2.0 liters).

So I guess now that I understand a little more about the purpose of the acid rest, I might not even need to worry about it at all. I just need to find out how low my acid rest will bring the pH and go from there.

 

[BigEd]

Thanks for your input-- being from a similar region as I am I appreciate your experience with this.

I typically don't try to match water profiles. My standard practice is to bump up the calcium over 50ppm and then get the sulfate / chloride ratio and levels where it should be for the particular style I am brewing. After that, I just tweak things slightly until the predicted mash pH hits 5.3 or 5.4 and I am good to go. I typically never need to use acid except for the in the sparge water.

In this case, I am already at the Pilsen water profile so I thought why not go with it? As for the calcium, I read up on the brewing methods of Pilsner Urquell and the brewery says their source water only has 10ppm calcium. I did modify my water profile slightly to get it up to 11ppm. Is the principal concern here the health of the yeast? I am making a pretty good starter for it (2.0 liters).

So I guess now that I understand a little more about the purpose of the acid rest, I might not even need to worry about it at all. I just need to find out how low my acid rest will bring the pH and go from there.

I assumed you weren't doing a triple decoction and went with that. Since you are you can use an acid rest to lower the pH. That's how they did it originally with that very soft water. However, modern malts are processed to be able to be used with very simple mash schedules. Unless you can obtain undermodified malt you may want to skip the acid rest and use the acid malt or acid to temper the pH. I'd keep any low temperature (<125/F) mashes to a very short duration or start at ~128-132F and climb from there.

 

[Beezer94]

From www.braukaiser.com

The mash pH can also be affected by the chosen mash schedule. The boiling of mash in decoction mashing, for example, lowers the mash pH. I have seen a pH drop of up to 0.2 pH units during decoction mashing. This decrease of mash pH might be attributed to the enhanced precipitation of calcium and magnesium phosphates [3]...

...The acid rest is a convenient rest to do mash pH adjustments. Not only does it serve to lower the pH by simply using the phosphatase and other acid forming enzymatic activity, but since there is no enzymatic activity that can have a detrimental affect on the final result, there is no rush to move to the next rest.