Figure 4-1. Yeasts in Heaven
The maturation of a mead depends in large part on the concentration of honey in the original solution, which is called must or wort. Let us suppose, to begin with, that you have really gone overboard in watering down your honey, placed it in a bottle with at least one tiny little yeast, and sealed the bottle to prevent air from getting in. Initially, this yeast finds itself in yeast heaven: plenty of sugar to eat, but not so concentrated that it cannot thrive, and plenty of oxygen to breathe. It goes to town, using up oxygen and glucose, producing carbon dioxide and water. Life is good, and while you should not exactly call it a sex drive since yeasts do not have sex, they do reproduce, so one yeast becomes two, two become four, and soon you cannot swing a jawbone without hitting a yeast. But you have sealed the bottle, and if the air runs out before the sugar, the yeasts move into anaerobic mode, consuming glucose (but not oxygen) and producing carbon dioxide and ethanol. Now, recall that carbon dioxide is a gas, so the pressure will build up inside the bottle. If you do not let it out, the bottle will explode. Brewers have fancy one- way valves, called fermentation locks, that let gas out but not in, but we can make a simple one from a balloon and a bottle cap. The gas escapes the fermenting mead until eventually the sugar runs out, the yeasts starve to death, settle to the bottom as dregs, or lees, and a dry mead results, one which is not at all sweet because the sugar has all been eaten. If the bottle remains sealed, the mead will be naturally carbonated, a kind of apian champagne.
The story ends differently if we were not so liberal with the water at the beginning. The yeasts reproduce more slowly because the concentration is higher. As the sugar is consumed, the alcohol concentration rises, eventually to a level which is toxic even to yeasts, which are, in effect, stewing in their own juices. They die and fall to the bottom as before, but under these conditions, a sweet mead results because of the leftover sugar. If
we will know that the poor yeasts are dying of alcohol poisoning and we need add no more honey.
There is one more bug in the soup, so to speak. Yeasts are not the only microorganisms around, generally. There is, among other things, a kind of bacterium which thrives on alcohol when oxygen is present. This little fellow breathes oxygen, eats ethanol, and pisses out acetic acid, (CH3COOH) and water, according to Equation 4-1(c). As you know, spoiled food often tastes sour, and this taste comes from the acid. If we allow mead or wine to spoil unintentionally, we call it garbage. If we allow it to spoil intentionally, we call it vinegar. Go figure.
Figure 4-2. Fermentation as a Process
The fermentation process is summarized visually in Figure 4-2. This reactor, a fermenter, is symbolized by a stack of three circles, labeled by the alchemical symbols for air, water, and earth. This stack resembles a bottle, if you use a good bit of imagination, from which gas can escape at the top and solids can settle to the bottom. In the next section, we will use a 2-liter soft-drink bottle as a fermenter. The reactants, honey, water, and yeast enter from the left of the figure. The solid waste product, dead yeasts, exits the bottom of the figure from the circle labeled by the alchemical symbol for earth. The gaseous waste product, carbon dioxide, exits the top of the figure from the circle labeled by the alchemical symbol for air. The good stuff, the main product, a solution of ethanol in water, exits the right of the figure from the circle labeled by the alchemical symbol for water. You should familiarize yourself with these conventions, as similar schematics will be used throughout the book.
People will say that my vision of the fermentation of mead is just a theory, but it is unjust to use the qualifier, "just." Without a theory, all you have are a collection of isolated observations; the Sun rose today, it rose yesterday, and it rose the day before yesterday. Theory, not observation, leads you to expect that it will rise tomorrow. Theory provides a vision of why the Sun rises and projects that vision into the future. One theory might hold that the Sun revolves steadily around the Earth; another that the Earth rotates steadily on
its axis. Without theory you would neither expect the Sun to rise nor would you expect it not to rise. You would simply shrug your shoulders and say, "que sera, sera."
A theory may be right or it may be wrong. If you add yeast to honey and water but no gas is produced you will be justified in doubting my theory of mead. If you add yeast to honey and water and it smells of ammonia rather than alcohol you should definitely doubt my theory. If you leave your fermenting mead open to the air and it does not turn to vinegar you should probably flush my theory down the toilet. If my theory fails to account for any of your observations, either my theory is wrong or you have not really observed what you think you have observed. Perhaps your yeasts were dead. Perhaps your bottle contained urine instead of honey. Perhaps your bottle had no bacteria to oxidize ethanol to acetic acid. But if your observations check out then my theory is not "just a theory;" it is a failed theory. Perhaps you can modify it or extend it to account for your observations, but if you cannot then you ought to flush the old theory and start over with a new one.
Suppose, however, that all of your observations support my theory. Does that make it right? No. Perhaps there is an observation you have yet to make which, once made, will contradict my theory. Perhaps there is another theory which would also account for all of your observations. A working theory is simply a survivor. It exhibits fidelity when its predictions are confirmed by observation. It exhibits fecundity when it makes many, many such predictions. It exhibits longevity when it has survived test after test without contradiction. But history is littered with theories which thrived for generations, only to be driven to extinction by emerging competitors. In this sense every theory is "just" a theory. The word just, then, is not so much a criticism as a redundancy. Let us accept the theory of mead in the spirit in which it is offered, provisionally. As long as it accounts for the observations made to date, we might say that we understand those observations. It provides a framework for predicting the future without which we would be left, not with different expectations, but with no expectations at all.
OK, so back to my riddle. Under pressure from her relatives, my new wife wheedled the story of the lion out of me. They won the bet, I went off in a snit and killed 30 other Philistines, gave their clothes to my 30 "friends," and the honeymoon was over before it even got started. By then I had touched more dead bodies than you can shake an ass's jawbone at and it turns out that mead "counts" as wine, even though it does not come from grapes. All that remained of my Nazarite vow was my hair, but that is another story. In the end, I should not have said "Out of the strong came forth sweetness", but rather, "Out of the sweet comes something strong."
the company which produced the MSDS and the potential health effects for eye contact, skin contact, inhalation, and ingestion.
If you look on any bottle of beer, wine, or liquor, you will see a warning about the dangers of alcohol consumption. You must know that over-consumption is the biggest hazard involved in drinking alcoholic beverages. One of my students brewed two liters of mead and saved it for his 21st birthday. Having never touched a drop in his life, he proceeded to down the whole two liters in one evening. He passed out and his roommate took him to the emergency room, which, of course, was a sensible thing for him to do. This fellow made a full physical recovery, though his ego suffered a bruise or two. His parents chalked the whole thing up to growing pains, though I doubt they would have been so understanding if he had kicked the bucket. And this bucket gets kicked more often than it should by young people eager to taste the forbidden fruit. I can only advise you to start small and work your way up. Remember the old adage, "When your nose feels numb, it is time to put a cork in it."
Research and Development
You are probably wondering what you need to know for the quiz. I will tell you.
• You should know the meanings of all of the words important enough to be included in the index or glossary.
• Know that the alchemical symbol for water looks like a cup. The symbol for fire looks like that for water, but upside down.
• Know formulas for glucose, water, oxygen, carbon dioxide, ethanol, and acetic acid.
• Know equations for the aerobic and anaerobic fermentation of glucose.
• Know how the law deals with home-brewing. This is discussed in the next section.
• Know the equation for the production of acetic acid from ethanol.
• Know the life-cycle of the yeast.
• Be familiar with the hazardous properties of ethanol.
4.3.
In my experience, children seldom embrace vows made by parents on their behalf. For myself, that was certainly the case. It is in the nature of children to rebel against authority, even when that authority has their best interests at heart. And sobriety is certainly a virtue that should be cultivated, for drunkenness has ruined the lives of more men and women than even promiscuity. Nevertheless, I believe that knowledge is always better than ignorance, and so I will speak of home-brewing even though it may be controversial.
The law in the United States at the dawn of the twenty-first century is that people over the age of twenty-one are allowed to brew up to 100 gallons of beer or wine for their own personal use. This means that you can drink it, share it, or give it away, but not sell it. While it is childishly simple to brew mead, that does not make it legal for children to do so. The home-brewing allowance applies only to adults, not children. Even so, I believe that it would not be a bad thing for more parents to guide their children into responsible alcohol use rather than presuming that they will attain instant maturity at the age of twenty-one.
While mead is, technically, simpler to brew than either beer or wine, it is by no means a beverage to be sneered at. Mead brewing can be taken to as high an art form as any other and the choice of honey, yeast, concentration, and spice may be made well by some and poorly by others. It is my intention to get you started with a simple, but drinkable mead, leaving the perfection of the art to your own explorations. Our requirements are quite simple. We require a bottle which can be sealed, yeast, honey, and water. For this first mead, I will suggest materials which are most easy to find.
The choice of container is not particularly critical. It could be of glass, metal, skin, or plastic. One of the most ubiquitous of containers is the 2-liter soft-drink bottle, which is ideally suited to our purposes. It is easy to clean, it is not easily broken, it is designed to hold a certain pressure, and the cap can be tightly sealed. It is important that the container be clean and sterile or unwanted bacteria may turn our mead into vinegar. The easiest way to do this is to wash it with soap, which we will learn to make in Chapter 19. Once your container is clean, you are ready for the honey and water.
As I have said, the concentration of honey determines whether it will turn out sweet or dry. Now honey is not a pure substance, it is a complex mixture whose composition and
Technically speaking, only honey, water, and yeast are used to brew mead, but some additional additives may assist the fermentation and modify the flavor. A cup of tea will add nutrients needed by the yeasts for robust fermentation. The juice of one lemon will add additional nutrients as well as flavors. Pour any additives into the honey water, that is, into the wort.
Now, some people insist that the wort should be cooked. Cooking will kill unwanted microorganisms and remove protein from the honey. Others swear with equal conviction that cooking is not only unnecessary, but undesirable, for it drives off aromas from the honey. If you decide to cook your honey, place your wort into a pot, heat it on a stove until it boils, and keep it boiling for 5 minutes. A froth will form on the top. Watch that it does not boil over or you will have a bit of a mess on your hands. Turn off the stove and carefully remove as much of the froth as you can with a spoon. Whether cooked or not, add the wort to your bottle, hereafter called the fermenter, and fill it to the shoulder with cold water.
The choice of yeast is also a matter of taste. Wine yeasts, champagne yeasts, beer yeasts, there are even yeasts specifically tailored to sweet or dry meads. Home-brewing suppliers will stock a large variety of yeasts, but do not get hung up on the choice of yeast. For a first mead, even ordinary baker's yeast from the grocery store will make a perfectly drinkable mead. I should warn you that brewer's yeast is frequently sold with vitamins in grocery and drug stores, but this yeast has been killed and is intended only as a nutritional supplement. What you need is active yeast, which may come in either powdered or liquid form. Follow the package directions, generally something on the order of "Add contents of packet to one quarter cup of water and 1 tsp of sugar." You may substitute wort for the sugar. Wait 10 minutes. If the yeast is active, it will have at least doubled its volume with a frothy head. Otherwise, it's get up and go has got up and went. Add the yeast solution (not the frothy head) to your fermenter and cap it tightly. There should be 2 inches or so of head-space at the top. Yeasts like moderate temperatures (65-70?F, 18- 21?C), so put your fermenter in a place where you would find the temperature comfortable.
There are three stages to the fermentation. In the first, aerobic stage, the yeasts are multiplying and oxygen will speed up this process. Shake the fermenter to get air into the wort. Once a day, feel the fermenter to see whether gas is building up inside. If it is not, unscrew the cap, squeeze the fermenter to expel the stale air and let in fresh air. Replace the cap and shake up the fermenter and leave it for the next day. Within a few days, you will find that pressure has built up inside the fermenter, and you are ready for the next stage.
Figure 4-3. The Fermentation Lock
No alcohol is produced in the aerobic stage, only carbon dioxide and water. To get alcohol, we need to cut off the supply of oxygen. You will not shake the fermenter any longer because you want to avoid adding air to the wort. To let gas out without letting air in, we shall construct a simple fermentation lock, shown in Figure 4-3. It consists of a balloon and a bottle cap. Drill a hole in the bottle cap to let the gas out. The size of the hole does not matter; half an inch will do. Then stretch the neck of a balloon over the cap, as shown. Most soft-drink caps are ridged, which might allow gas to escape from the balloon. To prevent this, roll the mouth of the balloon back a bit, apply a generous amount of rubber cement,[1] and roll the mouth back into place. You will have created a layer of rubber cement to seal the balloon to the cap. You may apply some extra cement to the outside of the balloon to make the seal complete. After a few hours or even a day, the balloon will fill with gas as the fermentation gets going. If it does not, either your balloon has sprung a leak or your yeasts are dead in the water. Make sure your cap is screwed tightly to the bottle. Squirt a little soapy water around the neck of the balloon and look for leaks, which may be sealed with a little rubber cement. If there are no leaks
Make a new fermentation lock and put it on your fermenting mead. You may collect several of these balloons from a single fermentation.
If you do not need to collect carbon dioxide, you may simply burp your mead each day; unscrew the cap to let the gas escape, then screw it down again. Eventually, the production of gas will slow and you will observe a growing sediment at the bottom of the fermenter, the dregs, which consist of dead yeasts. The wort, which has been cloudy, will begin to clear, that is, the heterogeneous mixture becomes a homogeneous solution. If you suspect that the fermentation is finished, pour yourself a little taste; a dry mead should no longer be sweet. If you are serious, you should get a hydrometer from a home- brew shop, which will tell you how much fermentable sugar remains. A dry mead can be bottled when either your taste buds or the hydrometer indicate that the sugar has all been used up. If you want it to be carbonated, burp it only enough so that when you squeeze your fermenter, it feels pressurized, like an unopened soft drink.
Bottling a sweet mead is trickier because of the risk of having the thing blow up if the fermentation is not complete. For this reason, continue burping a sweet mead until the fermenter is no longer under pressure and check to see that no pressure builds up when it