Dark Grains for Clarity

[BigWilley]

Is there any scientific data to support the practice of adding a small amount of finely ground black malt to your lighter beers to improve clarity. I believe I first heard of this practice in a Papazian book where he claimed that some of the big breweries use this practice in their light beers. He brought attention to the fact that darker beers seldom have the same degree of haze problems as lighter beers. He suggested a couple of ounces of finely ground black malt added at the end of the mash cycle for a typical homebrew 5 gallon batch. Have you heard of this and can you give any reasons as to why it might work? i have used this technique a few times and found that you must be extremely careful not to add too much and throw off your srm.

[Cargill Malt]

It is true that a lot of brewers of light beers do add finely ground black malt but it is for color not clarity. Very light high gravity brewed beers are closer to water white than yellow so they do need a boost.

The only rationale I can imagine for better clarity would be the fines tightening up the lauter bed and giving a better filtration of the wort. Small quantites wouldn't achieve this though in my opinion.

Many of said large brewers have switched from black malt to extracts that they either purchase or make themselves which is further evidence that their motivation for its use is color.

In all things I suggest not messing with something if it actually works for you. I just can't come up with a reasonable rationale as to why this would help.

As far as dark beers are concerned there could be a number of factors. Lower beer pH may have an effect on the precipitation of protein phenol complexes for example. I think it's probably more related to the fact that it's much harder to detect haze in dark beers visually.

[gustavomartin]

THE EFFECT DESCRIBED BY PAPAZIAN IS DUE TO THE EXISTANCE IN DARK MALTS OF CARBONIZED GRAINS. TRY TO ADD ACTIVATED COAL INSTEAD OF DARK MALT (BEFORE FILTRATION, OF COURSE)

[gustavomartin]

This is true if you add, not a couple ounces but a bigger cuantity. In some countries it's not forbidden to add the aldehide of the acetic acid, and this really works (I don't agree with this practice but it works). Never the less, the best way to obtain a perfect wort is to work with good malt in a good practice basis. If your malt is not so good, you must adjust your process in the brewhouse (times and temperatures) and perhaps it would be a good idea to add external enzimes, check the amounts of hot and cold trub you take away in whirlpool and filtration and check your finning temperature.

[dick murton]

I understood the improved clarity to be due to the increased "ionic" attraction (I know this is not a strictly technically correct definition) of highly coloured materials such as found in coloured malts, which help to attract protien particles of hte opposite charge, forming aggregates large enough to settle out, or to be settled more easily when using copper or white finings.

It certainly used to be perceived knowledge that darker beers clarified better than paler beers, but of course some of this may simply be due to use of more highly modified malts in ales than in lagers. Much of any caramel addition on transfer from FV to MV can be stripped out if white finings are added at the same time or shortly afterwards.

I have never heard of adding black malt purely as a clarification aid, but you could use a portion instead of other coloured malts or caramel instead - but just beware the colour pickup.

Cheers

[Chip Tate]

If I remember correctly, Papazian's recommendation is to add an ounce or two of dark malt toward the end of the sparge. The goal of this practice is to reduce the pH of the late sparge runnings to avoid extraction of undesirable (like silicates) that could cause haze.

You are right that you have to be really careful about changing the character of the beer with this method. Adding the grains on top of the grain bed toward the end of the sparge is aimed at minimizing contact time and effect on the wort profile while utilizing the pH lowering effect of the dark malt when its needed most (toward the end of the sparge). Of course, you can also just acidfy the sparge water if necessary.

CT