I’m sure Martin will chime in eventually, but basically what I’ve learned from him and many others on this forum is for Hefes/German beers in general, using soft water is better. Calcium to 40-50ppm keep sulfate/chloride to 20 or less ppm. Use lactic acid to correct for mash pH unless you are using undermodified grain and doing a Ferulic Acid rest. If so, no acid addition until you check the pH during beta rest.
Edit:. To be clear, whether or not you are using well modified/undermodified grain, if you do a Ferulic acid rest, wait until after that rest and 10 mins into your sacc rest to take a pH reading and then, if necessary, adjust your mash pH to 5.4 (ideal) using lactic acid. You’re safe in 5.2-5.6. just try to get in that range if you have the means to take a quick pH reading with a temperature adjustment.
A note on the grain modification: I said that because I confused acid rest with protein rest and you should do a protein rest if using undermodified grain, however most grain us homebrewers get is well modified these days and there’s often no need to do a protein rest and can actually harm the head by doing one with well modified grain.
Apologies for the confusion, just wanted to clear that up. I may be incoreect, but this is basically what I’ve learned from others here. A lot will depend on how you’re doing your mash, by the looks of the recipe, I’m guessing your doing a straight single infusion. I say that because if you were to do a Decoction I would skip the melanoiden malt as you will get some color from the decoctions.
Good luck, don’t over think it, if you are in doubt, err on the side of softer water and just focus your efforts on getting the correct mash pH.
Yes, I definitely use well modified grain. I use a re-circulating herms single infusion. Ferulic Acid 122* for 20 mins. Raise temp to 150* for the remainder of mash. I use lactic to adjust pH.
I actually thought of using my Kolsch water profile for this recipe but wanted some other input.
Hefeweissen is a traditional Bavarian style and water from Bavaria is appropriate. Fortunately, the geology for most of Bavaria is similar and so is the water in the region. Munich is located within the region and the Munich water profiles presented in Bru’n Water provide you with examples of what a Hefe brewer might deal with. Both the regular and boiled profiles give you insight. Using either profile could be valid.
Bavarian water is pretty hard. However, it is predominantly temporary hardness and it can be reduced by pre-boiling the water and decanting off of the sediment. The regular profile is unboiled and the boiled profile is…boiled and decanted. For those of you that are up on the subject, you can tell that the reduced calcium and bicarbonate content of the boiled water means its softer and less alkaline. It’s better suited to brewing pale beers like hefeweissen. However, many German brewers employ saurergut in their brewing and it can neutralize the high alkalinity found in the regular water there. The hardness or softness of the calcium contribution is not really a concern in my opinion. Either way will work. If you want to enhance the haziness of the finished beer, the softer water will help keep yeast in suspension longer while the higher calcium content of the harder water does drop yeast out a little quicker. Your choice and neither is wrong.
So, you have a choice with regard to what water you elect to use…and either is appropriate. You can use the softer, boiled profile and you won’t have to use much lactic acid to bring the mash pH into proper range. Or you can use the regular profile and have to use more lactic acid in order to bring the mash pH into range. Notice that I mention LACTIC acid in both cases. In my opinion, these German styles must be brewed with lactic acid to produce anything remotely authentic to the style. That hint of lactate in the finished beer is an important element in the overall flavor profile. Saurergut and acid malt are both forms of lactic acid that are allowable under Reinheitsgebot. For any other brewer, using lactic acid is more precise and equally effective. The only thing you’ll miss when using lactic acid from a bottle, is the interesting nuances that acid malt or saurergut can provide. They aren’t as critical to the beer as the lactate ion is, but they might make a difference to you and your drinkers. Your choice again.
As you’ll note here, you have options for brewing water. The main thing that you’ll want to adhere to, is the relatively low chloride and sulfate content in the water. Both should be modest. The final thing to be sure to pay attention to is the mashing and wort pH. Bringing that pH to 5.4 or less is very important. Keeping pH that low does help keep the wort color paler. In addition, you do want your finished Hefe to end with a reasonably low beer pH and helping out by keeping the wort pH low assists your yeast in bringing the beer pH low. In fact, some German brewers perform a two-step pH modification where they bring the mashing pH to 5.4 and let that pH exist through most of the boil. They then add a dose of saurergut to the boil to depress the wort pH to around 5.2 at the end of boil. That early stage, slightly elevated wort pH aids in the conversion of SMM to DMS. That is important when you use lightly kilned malts such as Pils and wheat that are likely to have high SMM content. Good conversion to DMS is an important step in avoiding DMS notes in your finished beer.
There is plenty to digest is this post. But the bottom line is that paying attention to your water profile and your wort pH can pay off substantially in brewing Hefeweissen. I advanced a Hefe to the final round in the NHC many years ago and I’m pretty sure that my water techniques helped. You can benefit from this info too.