Why is my beer hazy, or even muddy looking?

So, you've probably read my post on sediment in beer, but if not, that's okay.

Every once in a while, the sediment or haze gets extreme, or, if you've had the beer before, unusual even for the particular beer you're drinking.

This is usually the case in draft beers which are unfiltered or undergo secondary fermentation in the keg, and there's a few reasons this happens.

First of all, it is perfectly natural, and perfectly normal, and not a sign of a flaw in the beer, and definitely not that the beer is unsafe to drink.

As the post above discusses, sediment or haze is usually caused by the dead yeast cells remaining in an unfiltered or bottle/keg conditioned beer.  This is why unfiltered beers, such as hefeweizens, wit beirs, and various Belgian beers are usually hazy and opaque.

On the other hand, sometimes the haze goes beyond opacity to actually make the beer darker, or almost muddy in appearance.  While in hefeweizens, these beers usually pour within the normal color range for the style, and unless you are familiar with the particular beer you're drinking, you might not even notice, it can be particularly alarming in Belgian wit beers, golden ales, tripels, etc.

The reason this happens is fairly simple.  Dead yeast cells are heavier than water and the other things that make up the majority of your beer.  If a keg of beer sits stationary for a while, the yeast will start to make its way toward the bottom of the keg and become concentrated there, causing a darker, more murky appearance.

The way kegs work is that the beer being pulled from the tap is actually coming through the stem of the barrel from the bottom of the keg.  This means that, depending on how long a beer has been sitting in a color, and how it was stored, the beer can be darker at either the beginning or the end of a keg.

If a keg has just been tapped, and is pouring with a muddy color, it is likely a sign that the beer has been in the bar's cooler for a while, and has been stored upright.  Luckily for us, most unfiltered beer styles are not harmed, and may actually get better, from aging.  On the other hand, if the keg gets darker toward the end, it is usually a sign that the beer has been on tap for a while, or was stored upside down before being tapped.  In fact, many brewers recommend that their unfiltered beers either be stored upside down, or are agitated just before serving.  The reason is that this way, the yeast is concentrated at the top of the keg.  If the keg is on tap for a reasonable amount of time (a few weeks), the yeast will slowly settle, and the beer shouldn't pour "muddy" at all.  On the other hand, if the beer is particularly popular, and moves quickly, the yeast concentrated at the top of the keg won't have time to settle/spread throughout the keg, and when the end of the keg is reached, the beer which was formerly at the top of the keg will have a high concentration of sediment, and will pour with a murky/muddy appearance.

As mentioned in my sediment post, I have heard (from very unscientific sources, of course), that the dead yeast cells are actually very nutritious.  In most draft beers, they may affect the mouth feel of the beer, but honestly, if you were to blind taste the "bottom of the barrel" against a glass from the middle of the keg, you wouldn't know the difference.

So don't let the dirty/muddy appearance of that beer scare you.  Enjoy it!

What's With the Sediment in My Beer?

This is a follow up post to my post on sediment in wine,  A lot of the same questions apply to beer, and some of the answers are very different.  What is the sediment in my beer?  Is it good?  Is it bad?  Should I drink it?

First, what is the sediment?  Like wine, there are a couple of answers to this.  The most common answer is that it is the yeast remaining in the beer.  This happens for two reasons.  One is because a beer was bottled unfiltered.  The other is that a beer went through bottle conditioning.  There are some situations in which a sediment or haze could be a sign of bad handling of the beer some time between brewing and consumption.  Mostly, though, this is a deliberate choice by the brewer, whether traditional or untraditional to the particular style of beer.  Unfiltered beers have dead yeast cells (lees) deliberately left in the beer in order to contribute to the flavor, color, and body of the beer.

Bottle conditioned beers undergo a secondary fermentation, usually with the intention of adding carbonation naturally, in their bottle.  The dead (or, in some fresh, bottle conditioned beer, even living) yeast obviously remains in the bottle.

In terms of if the sediment is good or bad, with the exception of beers which are not intentionally hazy, the haze and sediment is usually a good thing.

Should you drink it?

Well, that's really quite a subjective question.  The lees add flavor, body, and texture to a beer.  They are also, apparently, quite nutritious, offering protein and lots of vitamins.  That being said, I'm a big texture person, so too much can leave a chalky or gritty mouth feel.  This is why, at a great beer bar, the server will ask you, before serving you a beer which throws sediment, if you like the sediment.

My personal preference varies on the size of the bottle the beer comes in.  That sounds strange, right?

Well, if a beer comes in individual serving bottles, and has been poured properly, and is agitated ever so slightly before service, the sediment is spread out throughout the beer and quite manageable.  If, however, the beer is served in a large format bottle (like a 750ml bottle), and has been sitting upright, ALL of the sediment is likely to be present in the last glass served.  That's a bit much for my personal taste.  Similarly, draft weiss beers and belgians often throw a lot of sediment, even enough to turn them from pale gold to hazy gray in color, toward the bottom of the keg, particularly if they are served upright.  Those last few glasses are a bit too much sediment for me.

At the end of the day, if you are drinking a Belgian beer, a wheat beer, or even some British styles, chances are the sediment in your beer is harmless at worst, and tasty at best.  It's really your choice whether to indulge or stick to just the liquid!

What Exactly is Malolactic Fermentation???

Wine geeks and professionals often use terms that can be difficult for the casual consumer to understand.  Usually, though, at least the major point of the words, can be broken down pretty simply.  One example of that is malolactic fermentation, which I'm going to try to break down pretty simply and then at least at an introductory scientific level.

The easiest way to understand malolactic fermentation is to actually look at the words themselves.  Fermentation is the action of yeast converting sugar into alcohol and carbon dioxide, at least at the most basic level that most of us drinkers need to/want to know about.  The reality of it is, much like our own digestive process, or any other chemical reaction, there's a lot more going on.  In the case of malolactic fermentation, one of the results is the conversion of malic acid into lactic acid.  Hence the name malolactic fermentation.  Malic acid is the tart acid which tastes a lot like a green apple or tart pear.  Lactic acid is the acid found in milk, butter, and other dairy.

So, on its most basic level, malolactic fermentation is fermentation which turns tart, apple-like acids into creamy, buttery, acids.  Chardonnay is the varietal where this simple breakdown is most evident, and most easy to understand.  On the other hand, malolactic fermentation is either desired, or not desired, in many other varietals, which neither start out with such a sharp green apple taste, or end up quite as buttery as many chardonnays do.

The Science Behind It
Malolactic fermentation usually uses one or more of three different types of bacteria, Oenococcus oeni, Lactobacillus, and Pediococcus.  Each of these bacterias eats up tart malic acid and spits out lactic acid and diacetyl.  Lactic acid provides a smooth, creamy, round flavor and mouth feel, and diacetyl, which is often considered a fault in both beer and wine, provides a buttery flavor and aroma (think movie theater popcorn).

Again, Chardonnay is the most extreme example, but most red wines, and many whites, undergo some malolactic fermentation.  The original flavor profile of the wine, the environment in which malolactic fermentation occurs, and many other factors affect how obvious the flavor effects are on a wine.  On the other hand, many crisp, tart, fruity, and floral whites are produced in such a way as to almost eliminate the possibility of malolactic fermentation, in order to preserve the sharp acidic notes in the wine.

Malolactic fermentation can occur either as part of the primary fermentation, or after the wine has been fermented.  It can and does occur naturally, or the bacteria can be deliberately introduced.  It is almost always done either during fermentation or aging, and almost never in the bottle.  One increasingly rare exception is certain Vinho Verdes from Portugal, which underwent malolactic fermentation in the bottle, since slight effervescence is expected in the wine.  This is less popular now, as wines which undergo fermentation in bottle also throw a sediment and pour less clear.

Hopefully this post helps a few people understand a little more exactly what malolactic fermentation means, and more importantly, why they should care about it when buying or drinking wine!