Clear Your Beer: Cut through the haze and fine your way to maximum clarity
Historically speaking, clear beer is a recent invention. For most of its history, beer was a dark, cloudy beverage. In British pubs in the 1100s, patrons would pass around an earthenware bowl with lines marked on the inside. Each patron would “take it down a peg” for a penny and pass the bowl on. In those dark, smoky pubs the appearance of beer was basically irrelevant.
Attitudes towards the appearance of beer began to change with the widespread use of clear glass. Once beer drinkers could see their beer, they began favoring clearer beer. Today, bar patrons want crystal clear beer for their pennies.
For the homebrewer, clearing is both an aesthetic concern and a stability issue. Clear beer not only looks better, but it is more stable than cloudy beer. A beer with
elevated levels of haze will have the tendency to deteriorate rapidly.
Types of Haze
There are different kinds of haze that form in beer. These include permanent haze, yeast haze and chill haze. Permanent haze is, as the name suggests, a haze that does not go away. The presence of permanent haze is evidence of a serious problem in the brewing process. Once formed, it cannot be eliminated without further damaging your beer.
Permanent haze can be due to biological contamination or an excess of starch in your wort. If the haze is biological, you need to pay closer attention to your cleaning and sanitizing procedures. If you have starch haze, you need to ensure you are getting complete conversion in your mash. Don’t run your wort off until the iodine test gives a negative result. If you use good ingredients and your brewing procedures are fundamentally sound, it’s not very likely that you will encounter this type of haze.
Yeast haze affects all beers unless something is done to counteract it. After fermentation, yeast can remain in suspension indefinitely. If you use flocculant yeast and store your beer cold, the amount of yeast haze in your beer will probably be minimal. However, if you want a beer that sparkles you will need to get rid of it.
Chill haze is a haze that forms when beer is cooled and disappears when the beer warms up. Repeated heating and cooling cycles can cause chill haze to turn permanent. Chill haze is formed when proteins in the beer bond weakly with polyphenols (also called tannins).
The level of chill haze in beer increases over time. There are three ways to minimize or reduce chill haze: reduce the amount of haze-forming proteins, reduce the amount of polyphenols and remove the protein-polyphenol complexes after they have formed. We’ll go into this in further detail a bit later in the article.
Assessing Haze in Your Beer
To see how hazy your beer is with your current brewing procedures, try this test. Take two of your homebrews and one commercially brewed beer of the same style. Leave the beers at room temperature until the day before the test. The night before, put one bottle of homebrew in the fridge. Leave the other out at room temperature. You can chill the commercial beer or not, it doesn’t matter.
Take three identical glasses and pour out the three beers. Be careful not to pour out any of the yeast sediment from the homebrews. Compare the commercial beer to the room temperature beer by holding both up to a window or light. Any difference in clarity will be due to yeast haze. The commercial beer should not have yeast haze and chill haze will not have formed in the room-temperature homebrew. Unfiltered homebrew will probably be clear, but it will have a slight
dullness when compared to the commercial beer.
To assess the amount of chill haze in your beer, you will need to compare the room temperature homebrew to the chilled one. Any additional haziness in the cold beer will be due to chill haze. As you will see, it’s chill haze that usually contributes more to the overall haze of your beer.
Finally, compare your cold homebrew to the commercial beer. After seeing your beer next to a crystal clear beer, do you want yours to look better? If you do, then you’ll have to keep reading to get the lowdown on fining techniques.
Techniques for Clearing Your Beer
A well-made and properly-stored beer will naturally be somewhat clear. The techniques listed in this column can help polish such a beer to make it much clearer. They are not designed to “rescue” poorly made beers.
Removing yeast haze from beer at the peak of fermentation, the concentration of yeast is about 50 million cells per milliliter. Most of the clearing happens without any interference from the brewer. Allowing the yeast to completely settle in secondary goes a long way towards eliminating yeast haze. Proper beer storage also helps minimize yeast haze. Ideally, beer should be stored at 40° F after it has bottle conditioned at room temperature. Once it’s ready, you should move it to a fridge or somewhere cold, and keep it there until you drink it.
Fining with Isinglass
Beer can be fined with isinglass to remove yeast cells. Isinglass is an extract from the swim bladders of sturgeon. Isinglass is rich in collagen, which binds to yeast cells in solution. The collagen-coated yeast drop out of solution.
Isinglass usually comes in powder form. New developments in isinglass powders allow for a simpler process. You can buy treated isinglass powders that simply dissolve in water. If you can’t find the powder, here is the traditional way. It works well at clearing yeast, but it does take some preparation time to use properly.
The isinglass solution must be made in advance and the pH must be adjusted. Finally, it needs to be stored cold to equilibrate. You should wait until the beer has settled as much as possible before adding isinglass. To fine your beer with isinglass, use the following procedure:
Step 1. Dissolve 30 to 60 mg/L in a volume of water equal to 1% of your batch size. For a 5-gallon batch, add 0.5 to 1.0 grams of isinglass to 200 mL of water. Use distilled water. For best results, gradually add water to the powder.
Step 2. Lower the pH to 2.5 to 3.0 with phosphoric acid. Add the phosphoric acid gradually and check the pH as you go. Be sure to stir thoroughly after each addition and wait a minute after stirring before you take a pH reading.
Step 3. Store the isinglass solution in the refrigerator for two to three days before use.
Step 4. Add to your beer. If you use a bucket, you may want to stir quietly with a sterilized spoon. If you ferment in a carboy, give it a little swirl to distribute the isinglass. In either case, try not to disturb the wort too much.
Step 5. Allow the isinglass to settle overnight.
Step 6. Bottle or keg your beer.
Removing haze-causing proteins from beer
Limiting the amount of haze-causing protein in your beer starts before you start brewing — before you even buy your ingredients, actually. Brewing strains of barley have been selected to be low in protein compared to feed strains. The choice of brewing ingredients can also affect beer clarity. Beers made with dark malts are usually clearer than paler beers.
Throughout the brewing process, there are opportunities to remove protein from your beer. For all-grain brewers, certain malts may require a protein rest. (Most modern malts are well-modified and don’t require a protein rest.) When the wort is boiled, a “hot break” is formed. This break material, which is partially composed of proteins, should be left behind in the kettle when the beer is moved to the fermenter. Likewise, the cold break is left behind when a homebrewer moves his beer to the secondary. And finally, proper storage reduces the amount of chill haze in beer.
If stored cold, chill haze will form and settle out of your bottles in about a week. You can prove this to yourself by comparing a beer that has been in the refrigerator for a week with a beer that has been stored at room temperature and cooled overnight. (Whenever my wife complains that all the space in the fridge is taken up by beer, I immediately launch into a lecture on “protein/polyphenol precipitation.” It never helps, but I sure get a kick out of saying protein/polyphenol precipitation.)
Fining with Irish moss
Irish moss is a fining agent used during the boil. Irish moss is not a type of moss; it’s really a kind of seaweed. At the pH of wort (typically 5.0 to 5.5), Irish moss carries a negative charge. At the same pH, haze forming proteins carry a positive charge. Adding Irish moss to your wort attracts haze-forming proteins to it. The “moss” settles out after the boil, taking the proteins with it. To use Irish moss, follow this procedure:
Step 1. Wet 0.04 to 0.125 g/L Irish moss with just enough water to cover it. For a 5-gallon batch, use approximately 1.0 to 2.5 grams of Irish moss. A gram of Irish moss is approximately one teaspoon.
Step 2. When there is 15 minutes left in your boil, add the Irish moss.
Step 3. Whirlpool your wort before siphoning to a fermenter. The trub should settle into the middle of
the brew kettle.
Step 4. Siphon your wort to your fermenter. Minimize the amount of trub carried over from the kettle.
Fining with silica gel
Silica gel can be used to fine beer prior to packaging. Silica gel particles bind to proteins before dropping out of solution. To clarify your homebrew with silica gel, use the following procedure:
Step 1. Dissolve 0.3 to 0.5g/L silica gel in sterile water. For a 5-gallon batch, use approximately 6 to 10 grams of silica gel. Add just enough water to completely dissolve the solids, less than a cup. Add water
to the powder or gel, not the solid
to the liquid.
Step 2. Add gel to beer and stir or swirl lightly.
Step 3. Allow to settle overnight.
Removing all the proteins from your wort or beer is not advisable. A beer without any proteins would be bland and lack a head. Just as there are haze-forming proteins, there are essential head-forming proteins. Even though Irish moss and silica gel preferentially remove haze forming proteins, they can also remove foam-active proteins. Any fining procedure needs to strike a balance between removing enough protein to reduce haze, without removing so much protein that foam stability and mouthfeel
The typical dosage for Irish moss quoted in most homebrew books is on the low side of the range listed above. If your beer has chill haze, but still has a decent head on it, increase the amount.
Removing polyphenols (tannins) from your beer
Since “good” proteins can be removed along with “bad” proteins by protein fining agents, many brewers attack chill haze by reducing the amount of polyphenols.
Fining with Polyclar AT
The most popular polyphenol fining agent is “polyvinylpolypyrrolidine,” or PVPP. PVPP goes by the name Polyclar AT and is widely available to homebrewers through local supply shops and mail-order outlets. For fining with Polyclar, just use the following procedure:
Step 1. Dissolve 0.3 to 0.5 grams of Polyclar per liter of beer in sterile water. For a 5-gallon batch you will need 6 to 10 grams (approximately 2 to 4 teaspoons) of Polyclar. This will completely dissolve in a few ounces of water. Slowly add water to powder and stir.
Step 2. Add mixture to beer and stir.
Step 3. Allow to settle six hours.
Just as with protein fining agents, overfining with Polyclar can lead to problems. At high doses (higher than the quoted range), Polyclar can reduce the color and hop bitterness of beer.
Another method to use in place of or in conjunction with fining is filtration. Almost all commercial breweries filter their beer for appearance and stability. Filtration strains out particles of haze, yeast and sometimes bacteria to give a level of clarity that is far superior to fining methods alone.
Beer to be filtered is often fined first. Too much yeast, for example, can clog a filter. Alternately, beer can be rough filtered first, followed by a polishing filtration. Filtered beer can potentially suffer from some of the same problems of overly-fined beers. Filters can remove desirable substances in your beer along with the yeast and chill-haze. The details of filtration vary depending on the filtration set up, but these are the basics:
The beer is chilled overnight in a keg so that chill haze is formed. The filtration system is set up so that pressure is applied to head of the unfiltered beer keg. The unfiltered beer keg is connected to the filter, which in turn is connected to the dipstick of the receiving keg. The beer will flow out of that keg, through the filter, and into the receiving keg. The receiving keg is not completely sealed so CO2 can escape as the keg fills.
When deciding on how much effort to put into clarifying your beer, you should consider two things: How important the look of your beer is to you and how long you are going to store your beer. If you are giving some of your beer away or entering it in a contest, looks might be more important. If your beer is not going to be consumed quickly, clarifying it will keep it in good shape so you can enjoy it longer. The full treatment for clarifying a beer would include a yeast fining agent, a protein fining agent, and a polyphenol fining agent. Alternately, you could filter the beer for maximum clarity. If your beer is going to be consumed rapidly and you don’t mind a little haze, you might want to consider taking an easier route. Adding Irish moss to the kettle and Polyclar to the secondary fermenter before packaging takes almost no time. These two easy steps will significantly reduce the amount of chill haze in your beer.
Chris Colby is our featured contributor this month (see “Editors Note”). He is a science editor living in Bastrop, Texas.