Help with German Pils recipe

This is my first attempt at brewing a German Pilsner and first attempt at a Lager as well, so I am hoping for some help and any suggestions you might have for my recipe.

Batch Size: 6 gallons (into fermenter)
Efficiency: 60%
Boil Time: 90 Minutes
Estimated OG: 1.053
Estimated FG: 1.010
Predicted Apparent Attenuation: 80%
Estimated ABV: 5.7%
Estimated IBU: 32 (Tinseth)
Estimated color: 5 SRM

Grist:
13 lbs German Pils
.5 lbs German Munich (light - 9 SRM)
.5 lbs Carapils
.25 lbs Acid/Sour Malt
.5 lbs Dextrose Corn Sugar

Mash Temp: 150
Strike Water to Grain Ratio (qts/lb) 1.5
Mash Time: 60 minutes
Strike Water: 5.34 gallons at 164 degrees (to result in 150 mash temp)
Sparge Water: 4.58 gallons at 180 degrees (to reach 168 degrees for sparge)
Predicted Pre-Boil OG: 1.041

Hopping:
Hallertau - 3 oz (2.7%AA) @ 60 minutes
Hallertau - 0.5 oz (2.7%AA) @ 15 minutes
Hallertau - 0.5 oz (2.7%AA) @ 10 minutes
Saaz - 0.5 oz (3.6%AA) @ 10 minutes
Saaz - 0.5 oz (3.6%AA) @ 5 minutes

Yeast and Fermentation:
Yeast: WLP830 (German Lager Yeast)
# Vials: 2 vials
Days Old: 60
Starter: Yes - 1 gallon Single Step Periodic Shaking Starter
Fermentation: I plan to pitch the yeast at around 55 and ferment at around 52 for first 2 - 3 weeks, eventually ramping up to low 60's 2 - 3 weeks into primary to encourage fermentation to complete and to allow for diacetyl rest/reduction. Then, I plan to rack to secondary, cold crash to 32, and lager for 4 - 6 weeks before kegging/serving.

Any thoughts/suggestions on my recipe or any part of my process? Just looking through the numbers, a few things that jump out at me are the estimated OG, ABV, and IBU's. According to the BJCP style guidelines, it appears the OG is a little higher than the upper end of the range, and as a result, the ABV (5.7%) is higher than the guidelines for the style, as well. On the other hand, the estimated IBUs (32) look a little low relative to the high estimated OG. I am hoping to brew a pilsner that is in between Victory's Prima Pils (higher OG & ABV with more hop character and hop bitterness) and a traditional Pilsner (less hop aroma and flavor with relatively high bitterness and crisp, dry finish to accentuate the bitterness) you might be served in Germany. With that in mind, would you up the bittering addition, decrease the base malt, or leave it the same, given that the high attenuation/simple sugars should result in a dry finish that will accentuate the bitterness?

A couple quick questions on the starter and water profile:
Do I need to ferment my starter cold (in the 50's) at my primary ferment temp, or am I better off fermenting the starter warm (at roomtemp - 70 degrees)? I started the starter yesterday evening and it is currently at 70 degrees.

The city water where I live is considered "moderately soft" (average hardness of 118mg/Liter), but the city doesn't publish the mineral content for the most part. The only mineral content posted is the Sodium (14 - 36 ppm) and the Sulfate content (57 ppm). Since an important component of the German Pils is the water profile, I'd like my water to be appropriate for the style. I am planning on using distilled water for several (probably 3-4) gallons of the strike water and carbon filtered tap water for the rest. I was planning to add some Gypsum to the mash (in conjunction with 4 oz of Acid Malt) to drop my PH (due to the absence of any darker malts) and also to impact flavor - to increase the sulfates to accentuate the sharp hop crispness/bitterness that is characteristic of the style. My question is how much gypsum should I use, and will adding Gypsum by itself (to my mix of 3-4 gallons distilled and 6-7 gallons filtered tap water) be sufficient to emulate German brewing water, or do I also need to add Calcium Chloride (or any other brewing salts) in order to bring the mineral content where it needs to be?

My final question is regarding sour malt. I plan to use 0.25 lbs (2% of grist) sour malt to reduce mash PH. Will this have any noticeable impact on flavor, or will it only impact mash PH? Sorry for the long posting and all of the questions. I appreciate any help or suggestions. Thank you!

 

Have you personally had success brewing the German Pilsner style using 100% german pils malt? I suggested adding a small percentage of Munich based on an award winning (placed in NHC and some other competitions) recipe discussed on "Brewing with Style"/The Jamil Show on the brewing network. They explained that adding a small percentage of Munich can add just a touch of color to change the beer color from light yellow to gold. They also stated that it contributed a bit of biscuity, rich malty flavor that made the pilsner malt pop (or something like that).

Regarding the Carapils, I planned to add that to contribute some body (in the form of unfermentable dextrins) since I plan to mash fairly low at 150 (I didn't want the beer to taste/feel "watered down" or thin and runny - especially since I plan to boost the fermentability of the wort with Simple sugars to make sure it attenuates fully and finishes dry) and to assist with Foam stability and retention. My reason for adding dextrose is to increase fermentability of the wort so that it finishes dry and crisp. Based on equipment limitations, I cannot do a step or decoction mash, so my only option is single infusion. If my equipment would allow for it, I would rest for 40 minutes at 140 - 145 and again for 20 minutes at 160 - 165, but since it doesn't, I can really only go as low as 150 (since the starches supposedly don't gelatinize below 150) and still get full conversion.

 

Yes, I use a picnic cooler with a single stainless steel braid (From a water supply line), and so my efficiency is consistently poor. Depending on the OG, mash thickness, and amount of Grain, it varies. I've had as low as 56% (when using 25 lbs of grain for 5 gallon batch) and as high as 68% (when using 11 lbs of grain for a low ABV session beer). For average strength beers like this, I expect my efficiency will be around 60 - 62%.

I use @VikeMan 's BrewCipher, which apparently uses models designed by @utahbeer. Without adding any info about my source water, it assumes a sourcewater PH of 8. Based on the grist I have listed (without the acid malt or gypsum), it indicates a mash ph of 5.7. If I add 4 oz of acid malt, it brings the mash ph down to 5.55. Then, if I add 5 grams of Gypsum, it brings the mash PH down to 5.47 and brings the overall Calcium to 31 ppm and Sulfates to 74 ppm (which is fairly close to Kai's profile of Ca: 59 ppm, SO4: 63 ppm, Cl: 89 ppm). The only thing I appear to be missing is the Cl content.

 

That makes sense that it defaults to the assumption that your source water has 0 ppm of all minerals; however, isn't a PH of 8 a pretty reasonable default if you aren't sure of the exact PH of the source water? I've read that virtually all tap water is alkaline (at least to some extent) due to how it is collected at the water filtration plant. This is because water plants collect rain and river water (which by itself should be close to PH of 7), which picks up CO2 and Calcium from the soil. Then, these elements bind with the H+ ions, leaving a bunch of free OH-(hydroxide) ions, making the water alkaline. I know that without testing the PH, it is anyone's guess as to how alkaline the water is, but it seemed like an estimated PH of 8 would be reasonable.

 

I think my efficiency issues stem from a couple root causes. While the braid in of itself is not the problem, the braid, in combination with the placement of the spigot in the cooler is somewhat of a problem. the spigot is not on the very bottom of the cooler, so the braid doesn't lay flat directly on the bottom. Instead, the spigot is about an inch to 2 inches above the bottom of the cooler. This results in a fairly substantial amount of dead space at the bottom of the cooler. In fact, in my brewhouse parameters, I set the mash-tun deadspace to .25 gallons. As a result, once I've completely run the wort out into the kettle, there is quite a bit of liquid still trapped on the bottom of the cooler.

Regarding the crush, I do get my malt from my LHBS and they run it through the mill. To your point, that is probably part of the issue. I just looked at the malt I got for this recipe and there are quite a few whole kernels intact. The problem with the LHBS is that they will only run it through the mill once for free. Then they charge like 5 extra dollars for any additional runs through the mill, which I think is ridiculous.

 

My buddy actually just hooked me up with a size E medical oxygen tank, so I plan to use that on future batches, but I won't have a regulator and diffusion stone in time to oxygenate the wort for this recipe. As a result, I am planning on shaking the hell out of the carboy a number of times during the lag period to get as close to the maximum 8 ppm oxygen saturation point as I possibly can.

 

Thanks @CurtFromHershey ! I just sent you a pm with my email address.