Diamond lager and tartness

Ingredients
1

I’m a huge fan of Diamond lager yeast. So much so I have been using it exclusively for a couple years now. Brewing mostly German Pilsner, helles, festbier, and a tasty batch of American ish bock with 20% corn grits(my first cereal mash!)

The beers have all been great and I’m loving brewing more than ever since finding a reliable easy to use dry lager yeast.

However, when I compare my beers to commercial examples of the same styles there is a definite tartness. I’m not sure I dislike it but I want to know why it’s there?

I adjust my mash ph to 5.4 with acid malt.
I adjust my post boil ph to 5.2 with lactic acid for pale beers. The bock I did not adjust and post boil on that was 5.37 on its own.

I have repitched Diamond and still had the tartness.

I’ve wondered if it’s my water profile? I use RO water with (.5) grams per gallon of calc2 and caso4 each. I think that gives me about 70 ppm of sulfate. The beers are indeed nice and crisp maybe too much sulfate for the malty styles but excellent in the pils. I’m going to experiment with less sulfate for the malty beers.

I have measured the final beer ph degassed of the pils to be 4.2.

I don’t notice the tartness when I have used bry97 which I also love.

I don’t notice it in my hefe which I use 3068 on. Tried Munich classic and found it to be too phenolic. The liquid 3068 tastes so much better in the hefe to me.

Any thoughts on this would be appreciated!

2

I’ve used this yeast alot and never gotten any tartness.

3

I recently used Diamond for four lagers. All turned out unpleasantly tart. This is the only dry strain I have ever gotten unusual tartness from.

4

I have never gotten tartness in the years I’ve used it.  I think water might be a good place to start looking.

5

Water is straight RO with only cacl2 and caso4 added.

About to keg a helles with only .25 gram per gallon of each salt. Should cut the sulfates to around 30.

6

Water is definitely a logical place to start, but in my case it’s not that. I think it’s a palate issue, not a chemistry issue, i.e. I think my palate is just hyper-sensitive to one of the acids produced by the yeast.