Munich Dunel same ingredients differing bitterness

Brewing Processes
1

I have made 3 Munich Dunkel beers from Munich malts, Melanoidin malt, and Caraffa II malt, with Hallertau hops.  All three of these recipes used very similar proportions of malts and hops.  However, only the Munich Dunkel 1  gave me a nice easy sipping dark beer.  Dunkel II and Dunkel III  have bitterness in the aftertaste, and more in the Dunkel II.  I have tried to figure out what is causing this extreme bitterness and think I have an answer, and asking you all much learned than myself, if I might be on the right track.

I work at Fenn Valley Vineyards and Winery near Fennville, MI and have been there as the Associate Winemaker since 1999.  So I am familiar with pH, hydrometers, Brix and the like, but only started earnestly brewing just a couple of months ago.  This gives a bit of my background, AND I have been reading books and reading post… in fact that is what gave me the idea on what is happening.

I use water at the winery that is run through a water softener,  in our lab as well as the kitchen and tasting room dishwasher, for the making of my beer.  The other night I went to refill my gallon jugs as I use this water also for making coffee and cooking since our home water (on a well in the country) has iron and a bit of sulfur, not good for coffee pots and cooking.  Figured it would not be good for beer making because of the iron as well.  Anyway, the water is softened with Salt and Citric Acid that also removes the tannins.  The other night as I was getting water I tasted a small bit of it as one jug had filled.  It tasted salty…salty to the point I spit it out.  I  kept running water, but it never cleared.  It was as if some setting has gone haywire and is not flushing the resins as it should.

On one thread, elsewhere I read that another home brewer had issues with excessive lingering bitterness, like my Dunkel II and less extent, Dunkel III,  and his culprits was his water softener.

Is this an issue that is real or just a myth?

2

Ah, small town Michigan water. It often has seasonal variation. Softened water is usually not recommended for brewing as hardness is not bad, alkalinity is. Softening removes Ca and Mg, but leaves the alkalinity.

Try using RO water from the grocery, add 1 tsp of CaCl2 for 5 gallons. Check pH, you might want some alkalinity for a Dunkel. Estimate that with a spreadsheet, I use Brunwater.

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^^^^
+1

4

Since the user softens with both ion-exchange and citric acid, that must be some really hard water. Citric acid is an interesting addition since it both chelates metals (that includes Ca and Mg) from the water and neutralizes alkalinity. Conceivably, that is a good thing. But since the user is employing both treatments, it suggests that either one is insufficient alone…that’s HARD water.

With ion-exchange, we know that the metals in the water are exchanged for sodium or potassium. When the hardness is high, that means that the softened water will have high Na or K content. That often means that its going to taste salty. If the water has much sulfate or the brewer adds sulfate-containing salts, the interaction of sulfate with either Na or K is usually kind of harsh. So, that’s one potential harshness source.

The other harshness source is any alkalinity remaining in the water. For pale beers, there isn’t enough acidity from the grist and the resulting wort and beer can have high pH. That tastes dull, muddy, and even harsh at higher pH.

Definitely, change your water source.

5

Did you record the alpha acids of your hops for each batch?  Alpha acid is a huge factor too and highly variable.