Beer Clarity and Finings, Part 3

This is the third part of my four part series on improving beer clarity. In the previous sections we discussed how to measure clarity, causes of poor clarity, proteins and tannins and how to control and improve beer clarity through ingredient selection. Today we’re going to discuss both techniques you can use to improve clarity as well as finings that can be added to reduce haze in beer.

Mashing and Beer pH

• Low Mash pH is Better - As covered in earlier article on mash pH, keeping your mash pH in the 5.2-5.5 range during the mash has a number of benefits for the stability and flavor of your beer. In fact if you are shooting for clear beer, you should target the lower end of the range - as close to 5.2 pH as you can get. This is because higher pH levels are associated with more phenol and protein extraction.

• Strive for Clear Runnings (no Turbidity) - You don’t want to disturb or mix your grain bed once it has been set up. Perform a recirculation (Vorlauf) step by taking the first few quarts of your runnings and add them back to the mash until you get clear runnings. Do not rake, mix or disturb the grain bed once it has set up.

• Avoid Over Sparging - As you sparge your mash, the pH of the runnings will increase over time - typically by 0.2 to 0.7 pH. Higher pH will again result in more phenol and protein extraction as the remaining grains will have less buffering capability. So you don’t want to oversparge your mash - draw what is needed and no more.

• Treat the Sparge Water - Since the pH of the mash will be going up as you sparge, it is important to treat your sparge water to lower its pH, so you are not extracting additional tannins or phenols. I recommend treating your sparge water with the same amount (per liter or gallon) of acid you used to balance the original mash.

Improving Clarity in the Boil - Hot Break and Boiling

The boil is another critical phase for improving beer clarity:

• Hot Break and Skimming - The first thing you want to watch for as you are heating your pot is the hot break, where a nice foam of protein often forms on the top of the pot. Ideally you want a strong hot break, which means you should run your stove on high until it starts to form. The hot break, which often foams up and causes boil-over, is primarily precipitated proteins from the grains which coagulate on the top of the pot. Some people take to skimming the “hot break” from the top of the pot to cut down on the protein remaining in the beer, and I think this is a good idea if you are brewing a light beer. Skimming also reduces the chance of boil-over.

• A Strong Rolling Boil - A vigorous boil removes unwanted volatiles from the wort, and also helps to precipitate unwanted proteins and tannins. You want a boil that is vigorous and in constant motion, not just a few bubbles coming from the bottom of the pot.

• Longer Boils Are Better - A long boil (90 minutes is recommended) will help promote the precipitation of proteins and tannins and also reduce off flavors like DMS. A beer boiled for 90 minutes will be clearer than one boiled for 30 or 60 minutes. When working with Pilsner malt in particular, a long boil is critical to achieve clarity in the finished beer.

• Avoid Hot Side Aeration? - Much has been written about “hot side aeration” which is adding oxygen or air accidentally to the boiling wort. The truth is, yes, hot side aeration exists, but for most homebrewers it is not a major concern. The reason is that the effects of hot side aeration are quite small relative to the other factors were talking about here, so it is primarily a concern for commercial brewers. However, in general, I try not to splash hot wort around too much.

• Use Boil Finings - Boil finings such as Irish Moss or Whirlfloc tablets, usually added the last 10-15 minutes of the boil, will lead to more proteins and tannins coagulating out of the pot when you chill your wort. Both of these finings are based on Carrageenan, a positively charged chemical that is effective on proteins, tannins and also hop matter.

The Cold Break - After Boiling

Chilling your wort as quickly as possible after boiling will result in the coagulation of proteins, tannins, hop polyphenols as well as bits of grain or hop matter from the wort. The stuff that falls out is called the “cold break” and it starts forming around 140° F (60° C) as you chill your wort. An effective cold break does help promote both clarity and flavor stability in the finished beer. To do this you need a wort chiller such as a simple immersion chiller.

I know someone’s going to write in and complain that they make great beer using a “no chill” method (where the wort is not chilled and put in a cube until later) and I’ve drank some great beer made using “no chill”. However, I can tell you that there is quite a bit of scientific evidence (many papers) to support the fact that chilling your wort quickly (not slowly) results in better clarity and flavor stability. So while “no chill” works just fine for a lot of beer styles, it may not be optimal for some beer styles where clarity is critical.

I’m also a fan of separating the “cold break” from the wort before fermenting. For those of you using an immersion chiller, this is pretty easy as you can just siphon the wort from the pot to the fermenter, leaving the cold break behind. Commercial brewers often have a whirlpool system to leave the break behind. Those of you using plate or counterflow chillers may have some challenge, but if you can try to separate the cold break before fermenting, particularly for beers where clarity matters.

Those are a few tips on handling the mash and the boil, next week we’ll cover clarity considerations in the fermentation process as well as fermentation finings and filtering.

Cheers,

— Michael Myers, Sergeant-at-Arms