The nomograph & RA

[butterman]

The nomograph makes the following prescriptions;
Brewing a pale beer needs a RA of -60 to +60
Brewing a dark beer needs a RA of +120 to +240

My question is if you are not brewing to BJCP (competition) standards is there anything untoward, in terms of beer quality, in going outside these apparently arbitrary boundaries ?

Moreover, does RA affect anything other than beer color?

What is supposed to fit in the range gap of +60 to +120?

Thanks for your comments.

[ziggy]

It affects your mash pH and therefore the pH of the beer throughout the entire brewing process. The reason such a wide range is given is because if you are using more dark roasted grains they lower the pH more than crystal malts. So if you are making a dry stout with base malt and 10% roasted barley at 400L you probably want to be closer to 240 RA but if you are making a porter with the same SRM color but you are achieving that color using say 10% crystal 80L and 4% black patent you probably want to be more towards the 120 RA end of the scale.

SRM doesn't discriminate between crystal and roasted malts but pH does. That is the reason for the wide range.

RA has zero effect on color. It's all about pH.

[mabrungard]

Different malts have different acidity and that acidity doesn't always match up to the color they contribute. That is the reason that the RA vs. beer color approach is fatally flawed. Don't use it. Visit the Water Knowledge page of the Bru'n Water website to learn more about this issue.

[baltobrewer]

Ouch. Now my head hurts.

[Ozwald]

Ouch. Now my head hurts.

The dumbed down version: pH matters, color doesn't. Dark malts *tend* to have more pH lowering power. Even more so when the book was initially written, since there were less malt choices available to us. The nomagraph is an excellent guide to get you in the ballpark & will work out for the vast majority of beers, but it's not perfect. It's more of a learning tool to get you started & how to use RA as another tool in your brew belt.

[baltobrewer]

The dumbed down version: pH matters, color doesn't. Dark malts *tend* to have more pH lowering power. Even more so when the book was initially written, since there were less malt choices available to us. The nomagraph is an excellent guide to get you in the ballpark & will work out for the vast majority of beers, but it's not perfect. It's more of a learning tool to get you started & how to use RA as another tool in your brew belt.

Ah, thank you. Much better.