You say your pale ale’s a little hazy? You say you can’t read the newspaper through your pilsner? You say your stout looks like the murky bottom of an aquarium tank? Is that what’s troubling you, Bunky? Well, you’re hardly alone…
Let me preface here by saying that I have little experience with this problem, its causes, or its remedies. For some reason, almost all of my beers turn out pretty clear, and I really don’t worry about the issue, myself. If I were brewing for competition (or gods forbid, commercially!) I would be more concerned. But I’m not. So I don’t worry. Nevertheless, I have some insight and some suggestions.
First, a word from our sponsor, real beer. Big commercial brewers filter their beer. They strip it of all live yeast and basically bottle a “dead” product. Many small breweries, and virtually all home brewers, bottle a beer that still contains live yeast, this is how we get carbonation. So naturally there is more likelihood of a homebrew being cloudy. A careful pour will usually avoid a cloudy glass of beer.
Generally speaking, there are two kinds of cloudiness in beer. The first is suspended materials, either proteins (from malt and sugars), or yeast. This kind of cloudiness is both preventable and somewhat fixable. The second is due to infection, bacterial or other. This is, to a certain extent, preventable, but not really remediable after the fact.
To prevent infections that can cause cloudiness (as well as off-flavors and aromas), sanitation is the key. All equipment must be not only clean but also sanitized. Chlorine bleach, iodine, really hot water, autoclave… whatever method you choose, you cannot get your equipment “too sanitary”. This includes all items that come in contact with the beer after boiling – wort chiller, spoon, hydrometer and test jar, fermenter, lid, airlock, etc. etc. And do keep your brewing area (kitchen, cellar, garage, man-cave…) clean, dust-free, pet-free…
The other aspect of prevention is quick cooling and pitching. The longer your wort sits waiting to begin fermenting, the more possibilities there are for wayward ambient flora and fauna to invade. Unless you brew in a sterile lab environment, there are bacteriae, wild yeast, and many other creatures in your brewery just waiting for a snack. Try to chill the wort down and pitch the yeast within an hour of the end of boil, if you can. If that’s not possible, keep it covered/sealed until it is cool enough.
To prevent the suspended matter from becoming haze in the finished beer, or to remedy existing haze, there are a couple of things that brewers try. I don’t generally use any of these, so I only know about them second-hand, really. The first is Irish Moss. Irish Moss is actually a seaweed, also known as Carrageenan, often used as a preservative (in ice cream, for one example). It is added to the wort (1 teaspoon to 1 tablespoon, depending on the wort volume) and is supposed to attract protein particles and bind them, precipitating them from the wort. The only time I used Moss I got a beer that tasted like iodine, and I have not used it since.
Some brewers add “finings” at various later points, during primary or secondary fermentation, at bottling, etc. There are basically two types, gelatin and isinglass. Now, I don’t know about you, but the thought of putting gelatin (made from beef/horse/pig hooves and skin, right?) or isinglass (which is derived from dried fish bladder) in my beer just doesn’t work. I’d rather have cloudy beer, personally. But that’s me. Besides, my daughter is a vegetarian, and she could not drink my beer if I used gelatin or isinglass. You brew for you, so you can “fine” your beer any way you want. If you buy gelatin or isinglass, it will generally come with instruction as per amount, application, etc. There are a couple of newer chemical compounds but I have no experience with them. I’d be happy to hear from other brewers in this forum – what do you use, how much, what results have you had?
The best way I’ve found to ensure that my beer is clear is proper aging and temperature. If you rack your beer to secondary too early, you risk interrupting and maybe even stopping the natural fermentation cycle of the yeast. If you try to bottle before fermentation is done, not only are you headed for potential over-carbonation (and therefore possible gushers, broken bottles, etc…), but you may also prevent the yeast from properly flocculating (settling out of suspension). Always, always, always let your beer age, let it settle, let it clarify as much as possible in the secondary fermenter. And cooler is better, for secondary aging. Once the majority of fermentation is complete (in the primary, during the initial 7 – 10 day period) almost every yeast benefits from cooler temperatures – as low as 35° for lagers, 50° for ales.
My one exception is when I brew with fruit. I make a few different meads, throughout the year, and frequently add fruit to them – elderberries, strawberries, cherries, etc. My annual Lambics are aged on cherries and blackberries, sometimes on apples or blueberries. In almost every case, these fruits contain pectin, the substance that allows fruit sugars to “solidify”, producing jelly. I don’t want my fruit meads or my Lambics to be consumed by the spoonful or spread on my toast, so I will generally add a little pectic enzyme in the last couple weeks of aging, just before bottling. This enzyme breaks down the pectins and I do appreciate the crystal clarity which results.
Bottom line: if it bothers you, you can do something about it. If it doesn’t, you don’t need to. As long as you like your beer, it’s good.