Why is pH important?

[captianoats]

Why do a lot of recipes have the pH of the water in the recipe? I understand wanting good tasting water, but why does pH matter?

 

[grathan]

In all-grain brewing it is important to get a proper mash ph because the enzymes work best at certain ranges, much like mash temperatures.

A high mash PH can also extract harsh flavors from the grains.


Hot break formation relies on keeping the PH above 5 in the boil kettle.


A low ph in the bottle keeps micro-organisms at bay.

 

[LBussy]

pH matters most for all grain brewing, where using water with pH too high will start to extract some nastier flavors. The lower pH helps to reduce the nasties that might take hold as well, brewing yeast is tolerant of a lower pH. If you are an extract brewer there's no reason to worry about pH at all since 99.99% of the time the water chemistry will be over-powered by the concentrated malt which is at the correct pH.

If you are doing partial mashes or specialties, using something like Bru'n Water will help you estimate how much acid to add, or you can treat your steep water by drops of lactic acid using a pH meter till you get to about 6. This is less important with a partial mash and especially using specialty grains, but it is a good habit to get into, and will help you learn for when it really matters.

 

[LBussy]

Hot break formation relies on keeping the PH above 5 in the boil kettle.

I think you typo'd ... low pH. It's just like using vinegar in the water in which you boil eggs. It will coagulate the whites nearly instantly.

 

[Nightshade]

Pretty much what those two said but also hop utilization is affected in a big way depending on ph levels.

 

[Britinusa]

You want your PH to be in the 5.2 - 5.7 range with 5.5 being ideal this is because of the amylasas that convert starch into sugar, they convert best in the 5.5 range.