Hi mrre,
I like your question
I can maybe lend some assistance. This is currently exactly my area.
As a german trained (Ausbildung) brewer who has been working full-time a bavarian brewery for years and currently studying the Braumeister in Munich, I have some handy inside info on this style of beer. It's the bread and butter of bavarian breweries, and they (literally) wrote the book on brewing it.
Mark, as always, has offered some very important points.
I agree 100% with Mark that your water composition, although fairly important, is secondary to a few other vital factors.
Like he said, pitch-rate is fairly important (although not masssssively important if your malt, mash and other fermentation conditions are all good).
Fermentation temperature is the absolute most important factor when brewing bavarian lagers.
To repeat Mark's advice, fermenting at 8-10°C is a very good start. You could even ferment a bit cooler.
Then, as redreuben so beautifully put it: lager lager lager lager lager!!!!!!
If fermentation temp is the most important thing, lagering is definitely the 2nd most important. Especially getting it off the old yeast (racking). Lager it for at least 4 weeks. If you can, longer
The diacetyl "rest" up to 20°C is an option. But if your fermentation is right, it shouldn't really be necessary. If I were going to do it, I'd do it by turning off your cooling when you're about 75% of the way through your fermentation. I've heard this tactic mentioned from a few brewers, as it does have logic. However, as far as I know, it's not really common procedure in breweries here.
Now on to the mash.
Also critical of course. I'd need to see your malt analysis to really be able to optimise the mash program, but Mark's schedule is a very good starting point.
The typical bavarian mash schedule is sub 60 mash-in, 62-63, 70-73, 78-mashout decoction.
Depending on what the barley harvest was like last year ->> how the malt is this year (protein content!!!!!!!), one could consider a protein rest around between 50-60deg. As a rough description: 50-55deg will increase your Free Aminoacid content (yeast nutrient!!!!!) and 55-60 will increase your content of med.-high molecular *soluble* Protein (mM and hM-Protein) -->> head retention.
However, in general, malts are so well modified these days that that is *probably* not necessary. Like I said, if you have a malt analysis there, I could take a look and tell you what should be done.
One can always just mash in at around 52 than start heating straight away up to 62deg at 1deg/minute. It's also a bit kinder on the enzymes than hitting them with 62deg when they've been chilling out at say 15 degrees for weeks/months.
Regarding water:
pH (in the mash and at the end of the boil) is fairly important, but not near as vital as the above points. (In germany it's illegal to add raw minerals or lactic acid during the brewing process. There are numerous ways around this, but they're often too expensive or time consuming for a lot of smaller breweries.....and they still brew "crisp" bavarian lager).
With a pH of 5.5-5.6 you're right on target for the beta- and alpha-amylasen.
Regarding malt-bill:
If you really want to get it “crisp” I’d completely do away with specialty malts. We used to add a little bit of carahell, but only like 3%.
Another thing to be careful of in terms of keeping your end product “crisp”, is DMS . (Cabbage, cooked vegetable smell/flavour). This is exacerbated when the wort is between 80-100 (i.e. Whirlpool)
On top of all these things, one can definitely do some good fine tuning with water chemistry, but as already mentioned here, all the other brewing steps have to be right.
Good luck and keep us posted on your progress with the next batches!
