Managing Salts, pH, flavor

[mchrispen]

I have a few questions about managing salt additions (in my case to R/O water) that I don't think have been completely clarified in the sticky thread. There seem to be disagreements about where and when salts should be added (HLT, MLT, BK) and how to manage pH (MLT & BK) in the process when these salts shift pH up or down.

Perhaps an easy way it to critique my interpretation and process on a baseline 5 gallon APA recipe, say the Sierra Nevada Pale Ale Clone from BYO 12/12 issue. I threw this into BeerSmith for convenience, but haven't adjusted for efficiency.

Amt Name Type # %/IBU
10 lbs 2.0 oz Brewers Malt 2-Row (Briess) (1.8 SRM) Grain 1 93.6 %
11.0 oz Caramel Malt - 60L (Briess) (60.0 SRM) Grain 2 6.4 %
0.50 oz Perle [8.00 %] - Boil 90.0 min Hop 3 15.4 IBUs
1.00 oz Cascade [5.50 %] - Boil 45.0 min Hop 4 18.2 IBUs
1.50 oz Cascade [5.50 %] - Aroma Steep 30.0 min Hop 5 0.0 IBUs
2.0 pkg Safale American (DCL/Fermentis #US-05) Yeast 6 -

I would be using R/O water for the entire volume, single infusion mash at 152F, batch sparged. Mash water volume is 3.5 gallons, sparge is 4 gallons - resulting in ~6.1 gallons pre-boil according to BeerSmith. Forgive my laziness here.

Bru'n recommends treating the 4 gallons of sparge water with 1.79 ml phosphoric (10%) to achieve 6.1 ppm CaCo3, targeting a 6.0 pH. (Tab 2. Sparge Acidification, per instructions)

On Tab 3. Water Adjustment, I am selecting the "Yellow Bitter" profile, and setting RO as 100% dilution. With the grain bill set in Tab 4. Mash Acidification, I am seeing a predicted mash pH of 5.4, without the use of liquid acids. Additions are below:

Mash Additions:
Gypsum 1.8 grams
Epsom 1.1 grams
CaCl2 1.1 grams

If these additions cause the pH to drop below 5.2, which is not predicted, then I would adjust using pickling lime or baking soda over the first 30 minutes of the mash.

Sparge Additions:
Gypsum 2.0 grams
Epsom 1.2 grams
CaCl2 01.2 grams

I typically add the "sparge" additions to the kettle, not the HLT. I assume this split of the additions is to:
1. Provide an optimized mash pH
2. Flavor and wort benefit in the kettle from the remaining salts addition

Questions:

Am I using this tool (Bru'n Water) correctly? I would, of course, verify the addition results with a pH meter throughout the mash and sparge.

What is the expectation of the boil pH? I believe it is a function of the mash pH interacting with any residual buffering (if any) in the sparge water, which will be further reduced in this case by the acids added. I assume there is a pH driven flavor impact here as well.

I realize I am over complicating things a bit - but it is important for me to understand WHY, or at least the pros/cons to give me a shot at an educated choice. I did buy the Water book - and looking forward to reading it.

 

[mabrungard]

Matt,

In some respects, mineral and acid additions are a personal preference. However, there can be benefits to adding them in certain ways. I see your dilemma regarding when to add additions that were calculated for the sparging water addition. I'm not truly sure if there is a 'better' time to add those additions, but I feel that there can be an advantage to adding them to the sparging water in order to increase the osmotic stress on the malt components and reduce the extraction of tannins. That is just a theory, but I do have some sensory tests that suggest that does help.

Since certain mineral additions affect the residual alkalinity of the mash, getting those additions correct is an important effort in producing a desirable mash pH. The other additions to either the sparge or kettle are primarily to produce the overall ion content for beer flavor effect. (Although boosting calcium has other beneficial effects).

I see that you are using RO water. I assume that RO water does have alkalinity of less than 25 ppm as CaCO3. Under that assumption, you shouldn't need to acidify that water. While I do recommend acidifying sparging water to somewhere between 5.5 and 6.0, I also comment that the ultimate target is bringing the alkalinity to less than 25 ppm. You don't mention the phosphoric acid strength, but I'm sure that the quantity of acid needed to bring the pH down is quite small.

You are correct regarding the need to adjust the mash pH in a timely manner. I suggest that you would want to adjust it as soon as you were sure it was incorrect and wasn't correcting itself through the mash chemistry. I brew with a RIMS and the amount of mixing I obtain via the circulation is high. My mash pH typically is stable within 5 minutes. If your mash is hand mixed, then it may take a bit longer to stabilize. I would hope that you would know within 15 minutes. 30 minutes is a long time in the course of a mash.

The overall wort pH in the kettle is somewhat forgiving. There are effects on protein coagulation and hop utilization and flavor is another effect. Keeping the kettle wort pH within the 5.2 to 5.6 range helps avoid serious degradation of the coagulation and utilization effects. But another refinement available to brewers is the adjustment of that kettle wort pH to enhance flavor effects. Biasing the pH to the low side can increase the tartness and crispness of the finished beer. That is probably always a good trait. However, when the percentage of dark grain increases, I find that a low wort pH can be a little overwhelming. Under that condition, boosting the kettle wort pH to the high side of the range can help soften those roast flavors. The higher pH also improves color and flavor extraction from the dark grains. The higher pH also improves the extraction and utilization of the hop components, so you might not want to let the wort pH be too low when brewing a hoppy and bitter beer.

I hope this is helpful.

Enjoy!

 

[mchrispen]

Thanks for the quick reply. A couple of points of clarification - I use 10% Phosphoric as it is what is available at my LHBS and I have used it since I started brewing. I also have a RIMS system and recirculate during mash and at the initial part of a batch sparge to vorlauf. I stir at dough in and occasionally if I see my recirculation starting to slow. Usually just leave it alone. I check pH at dough in, as well as 5-10 minutes after and then about 30 minutes into the mash. Since using R/O I have not seen any unpredictable results.

Your recommendation for using the salts in the sparge water make sense... so I would then not use any liquid acid (my R/O is generally between 6.2 and 6.4 depending on how long it has been flowing) and allow the acid salts to lower the pH to where it will.

So with a darker beer - say a dunkelweiss, then I should also be considering lime or soda additions to buffer the pH in the mash to counter the roast's acid contributions. I have used your recommendations of tasting minerals added to finished beer and really dislike both pickling lime and baking soda at a very low threshold, however don't mind a little sea salt. I did this in a side by side flight of the same APA.

Thanks again for the advice.