Picking a Yeast

For my first batch of wine, the gal at the homebrew store handed me Red Star Premier Cuvée yeast. Later, I asked around, and was told that Montrachet yeast ate through concrete. This last time, on a whim, I bought Lalvin 71B-1122 and K1-V116. How are they different? Why are they different? What is the best one for the batch I am making/going to make? Answer is – look for the tables.

There are probably hundreds of manufactured yeasts out there, and each one is better for a particular type of ferment style (beer, wine, cider, mead, sake, etc), a preferred temperature which they ferment at, at what point they die because the alcohol poisons them, the flavors they give off, and how vigorous they are.

I have made a list of websites that help when it comes to picking out yeast for wine, mead, and cider.

• http://www.gotmead.com/index.php?option=com_content&task=view&id=1940&Itemid=14
  
• http://winemaking.jackkeller.net/strains.asp
  
• http://www.winemakermag.com/guide/yeast
  

Other good places for research include yeast maker’s websites, such as Wyeast, White Labs, and Lalvin.

Another thing to consider when shopping for yeast is how available it is to you. It might be difficult to buy some yeasts in your area and/or have them shipped to you.

Of course, purchasing yeast isn’t always necessary. Grape wine makers rarely use commercial yeast, and instead let the natural yeast that have deposited on the grapes do the fermenting. The same is true for apples if they are not washed prior to pressing. However, if potassium metasulfite is used on the juice to kill bacteria, it may inadvertently kill the weaker, less populated wild yeasts. Options are take a risk that the wild yeast will survive, not use potassium metasulfite and risk bacteria growth, or go ahead and use a manufactured yeast, or at least have it as a backup.

How to Add Yeast

Adding yeast to beer wort or wine must to start the fermentation process is called pitching.

When I first started brewing, I would simply add the yeast to my batch. There is nothing wrong doing it this way, but it is not the optimal way. This is because it is sometimes shocked by temperature and the presence of so much consumable sugar.

The preferred way is a method called rehydrating. Take some water at about 100 degrees and add the yeast, and maybe a little bit of sugar, and then let it sit for fifteen minutes up to four hours. The yeast will begin multiplying a little bit and will create a little bit of foam, which is a good sign they are ready to be pitched into the batch.

The difference between the rehydrating and not is that rehydrating creates healthier yeast, which becomes evident as the batch will start fermenting sooner than if the yeast had not been rehydrated.

That said, there are times that I still don’t rehydrate. For instance, I’ve used Whole Foods unfiltered (unfermented) pasteurized apple cider several times now that I know what the SG and pH is, so I don’t need to take samples, and therefore do not handle any of the pasteurized juice. In an effort to reduce contamination from tap water, I will pitch the yeast without rehydrating it.

The important thing is to follow the directions for the yeast, because they are written to provide you with the most optimal conditions for that kind of yeast. My husband recently started a new beer, and the yeast he was using told him just to pitch it without rehydrating it. He thought this was odd, so he decided to ignore the directions, and he went ahead and rehydrated it. Well, that yeast kind of made these little globs, and when he pitch it, the globs floated on top of his beer wort, looking quite odd and causing him some alarm. I’m sure it will be quite fine, but goes to show that one should follow the directions on the yeast packet when it comes to pitching yeast.

Making a sweet or dry wine or cider

I have eluded to the fact that it is much easier to make a dry wine or cider than it is to make a sweet one. I think it is time to go a little deeper into the topic.

The yeast in cider and wine eat sugar, turning it into alcohol. Thing is, they will do that until one of two things happens. The first one is that the yeast run out of sugar. At this point, it is a dry beverage with no sweetness, which some may dislike. This process is the easiest to accomplish because it allows the yeast to do what it wants to do. To obtain a sweet wine or cider, one must interfere with the batch, either killing the yeast prematurely before all the sugar is gone, or making sure the yeast is truly dead before adding more sugar back. I will explore those options in the posts to come.

How do you know if the wine or cider is sweet or dry? The answer is as simple as taking a specific gravity reading taken with a hydrometer. That reading can be classified into the corresponding sweetness:

• 1.025 Very Sweet
• 1.020 Sweet
• 1.015 Medium Sweet
• 1.010 Medium Dry
• 1.005 Dry

It is not really recommended bottling much higher than 1.025, as most people would not find it very drinkable. Also, if the yeast starts fermenting again, the carbon dioxide released could create too much pressure on the bottle, causing it to pop the cork, or worse yet, explode. Ben Watson in his Cider: Hard and Sweet cautions against bottling cider higher than 1.005 if it has not been stabilized, that is, if chemicals or pasteurization has not happened to ensure the yeast will not start fermenting again.

Air is the enemy

Air is the ultimate enemy of cider, wine, and beer. More specifically, oxygen is the enemy of cider, wine, and beer. Every time a batch is made, all attempts to reduce the amount of air in the fermenting container, called headspace, is made.

Let me put it this way – if you bite into an apple, it starts to brown. This is called oxidization. If you put it down and don’t do anything with it, it might start to rot or mold. For that to happen, there needs to be little germs to eat the sugar and breathe oxygen. That is how a compost bin works, along with other bugs and critters to help the process along.

For brewing, I don’t want it to rot, I want it to ferment. Yeast needs sugar, but it does not need oxygen to work. I don’t need oxygen around my liquid, where, if there are any little germs in my liquid, it could allow them to breathe and ruin my drink. If that happens, it will smell and taste funny, or even turn to vinegar.

So after the brew is put into a container to ferment, with as little head space as possible, with the opening plugged. If everything goes right, the yeast will start to eat the sugar and convert it to alcohol and CO2. When the yeast first starts going to work, it releases CO2 so quickly that it can blow the plug out of the container, or it can even shatter glass due to the pressure build up. Instead, the plug is fitted with what is called an airlock or a blow off. There are two main kinds of airlocks, but both of them force the exiting air from the jug to pass though water and does not allow outside air, especially oxygen, back in. Actually, it is better to use cheap vodka instead of water in the airlocks for sanitization reasons. I had a batch that you could smell the juice on the escaping air, and it attracted fruit flies, and they managed to get into the air lock. I have heard stories of the pressure inside the fermenter dropping and sucking back the fluid in the airlock, so sucking back vodka that had killed the fruit flies and whatever nasty little germs they carried would be preferred to sucking back water with dead fruit flies and live nasty little germs they carried to ruin your batch, as having no oxygen present is not a guarantee that everything will be fine.

I mentioned a blow off. My husband’s first five gallon batch of beer started bubbling so fiercely that the little airlock could barely keep up. He had to remove the airlock and hook up a hose to the plug, and he stuck the other end in a pitcher of water with iodine, which is one of the sanitizers beer brewers use. It worked the same way as an airlock with the escaping gases passing though the water-iodine solution. In this case, he had to monitor it to make sure the pressure didn’t drop enough to suck the water-iodine solution back into his beer. Actually, after about two days, the yeast don’t have as much sugar since they have been eating it, and so the process begins to slow, at which point, the blow off can be removed and an airlock can be put in place again.

There is one other useful thing about CO2. Have you ever combined an acid like vinegar or lemon juice with baking soda? It has a chemical reaction and bubbles, releasing CO2. If you took a candle and placed it in a jar and then lit it, and then did this solution in another jar, you can “pour” the CO2 from the second jar into the first jar with the candle in it. The candle will “drown” in CO2 and go out because the CO2 displaces the oxygen the candle needs to burn. This shows that CO2 is a heaver gas than most air. It sinks, hence the reason it could be poured, and the reason it stayed in the jar to extinguish the candle. This is a good thing when I have to remove the plug from fermenting container to take a sample for measurements. It isn’t foolproof, but the CO2 should stay in the container near the liquid, and protecting it from the potential oxygen in the newly exposed air.

One last note about airlocks and air: I picked up from Andrew Lea was to put a little bit of food coloring in the air lock. This makes it easier to see the air passing through it. This is important because when there is no more sugar, the yeast die and fall to the bottom in what is called lees, so no more CO2 will be given off. If there is no more CO2 being given off, no more air will pass though the airlock, and it is time to move to the next step of the wine and cider making process.