Step mashing and pH question.

I'm planing on brewing a Wit this weekend that is a re brew of one I did last year. I'm using Bru'n Water to calculate the water for this one and it got me wondering about the step mash pH calculating and adjusting. I know that my final mash pH should be around 5.4 at room temp. Assuming that every time I infuse to reach the next rest my net alkalinity will increase, should I recalculate the mash and additions for each rest or adjust after dough in for the entire final mash volume? Hope this makes sense to someone. Last year I just adjusted up front and the beer turned out great but I'm always looking to improve.

I think I would figure out the mash water additions based on the final step infusion. Add that mineral and/or acid addition to the total batch of mash water and add the amount of that water in accordance to your step procedure.

Don't forget that Wit is a purposely tart style and possibly aiming on the low side of the mash pH envelope could be a good thing.

Thanks Martin. That's what I did last year. I notice that you have several Belgian city profiles on Bru'n Water. I planned on using the balanced yellow beer as the target profile on this one and just making sure I keep the mash as close to 5.4 as possible.

The color based profiles are moderately mineralized profiles that generally provide the amount of alkalinity needed for that color beer. Many of those City profiles are more mineralized than a brewer might desire in their brewing water. I think your track is the way to go. I still might aim for a 5.3 though. Wit should be a tart and refreshing style.

Any brewer who has not read Brewing with Wheat is well advised to pick it up and read Gordon Strong's comments on brewing wheat beer styles at the back of the book. Great information.

That sounds like a good plan. Is the difference between a 5.3 and 5.4 pH mash subtle in a beer like a wit or is it pronounced? Quite a few times in the past I have got the pH in the general range and called it good but it sounds like I have been overlooking an opportunity to really dial it in to style.

Mash pH really controls the enzymes that mediate the conversion of protein to lower molecular weight protein and starch to sugar. It does have an effect on kettle and thus beer pH but the major determinant of beer pH is, in the case of normal beers, the yeast strain (ale yeasts like and thus produce lower pH) and in the case of wit, the lactobacillus. So the difference of 0.1 point in the mash tun will make a difference but not noticeably in beer tartness. Mash pH of 5.3 will either produce a beer which is better, equal to or not as good as one brewed at pH 5.4. You'll need to do 2 brews to see which it is.

Some people brew wit using a lactic fermentation for tartness, some do nothing for tartness and some add lactic acid the finished beer fermented with plain of S cerevesiae. Obviously in the case where no souring in added, either by lactic fermentation or acid addition, mash pH will have a larger influence on tartness. Probably not much.

Thanks for the info. I guess I wasn't too far off base after all.