Article

Stabilizing, Barrel-Aged Cider & Adjusting pH: Mr. Wizard

Q

After brewing for a long time in Seattle, Washington I now find myself in extreme southeast Arizona. Seattle was a kitchen brewery but Here I have a shed dedicated to brewing good beer. Last week at 2:30 p.m., the temperature was 96 °F (36 °C) and down to 50 °F (10 °C) at night. Last night was 58 °F (14 °C) and back up to 85 °F (29 °C) at 2:30 p.m. I have a 5-gallon (19-L) batch of California cream ale fermenting. On the advice of a brewer from one of the suppliers, I pitched a cultured batch of turbo yeast high heat at 81 °F (27 °C). The fermentation seems to slow and stops according to the temperature. After two days of robust action it’s settled into an up-down routine. Tomorrow is two weeks and kegging day. My question is, do you have any ideas or thoughts on high heat brewing? My potential alcohol looks like 6.3% as opposed to the 4.3% called for in the recipe and I’m informed that turbo yeast high heat makes a lot of alcohol.
Bill Mayberry
Cochise County, Arizona

A
There are a couple of separate issues raised in your question. The first has to do with effectively stabilizing your fermentation temperature to prevent the yo-yo effect you describe. I recently described using water as a temperature buffer to address the very problem you describe, only that in the question I answered the brewer was in a pretty nice climate for brewing … your former home of Seattle. The desert climate is much more volatile and you are clearly seeing a fermentation pattern that really needs to be stabilized to help you produce clean beers that do your brewing shed justice.

The good news is that your average temperature is pretty normal and if you determined the normal temperature over an extended period of time, for example by allowing an insulated water cooler to sit in your shed for a week and measuring the temperature, you probably would find that that temperature is somewhere in the upper 70s °F (~25 °C). Maybe a bit warm for brewing some ales, but certainly not too high for a wide range of beers.

A cheap and easy way to dampen the changes in your fermenter temperatures is to place your fermenter in a plastic trashcan and to drill an overflow near the normal beer level in a full fermenter. The basic method is to fill the trashcan with water and immerse the fermenter. The water acts as a temperature buffer because of its mass (this is one of those times where size really does matter) and relatively high specific heat. In plain terms these properties make bodies of water relatively slow to heat and cool in comparison to something like air. If the normal temperature is not too warm for fermentation, or a few degrees cooler than your target temperature, the only thing that may be required is to fill the trash can up to the overflow level and leave it alone during fermentation.

Chances are that this alone may not work for you in Arizona and that your fermentation will be a little too warm. If this proves to be the case, you can add a water supply line to the bottom of the trashcan and displace some of the warm water. Consider using a needle valve to very slowly and continuously add water or manually turning the water on and off daily as required. This will only work if your ground water is cool enough.
I have never used “Turbo Yeast” but from what I can find online these strains are marketed for fermenting “wash” for distillation. The key traits that these yeast strains have are their tolerance for alcohol, high attenuation rates and rapid fermentation rates. These are not necessarily the things that make for the best brewing strains.

The higher than expected alcohol in your brews is likely due to the high attenuation rate of your chosen strain. But keep in mind that mash temperature really sets the stage for wort fermentability and that it truly takes two to tango when producing high-alcohol beers. If you have poor wort fermentability and a yeast strain that is described as highly attenuative, you may still end up with a high-finish gravity because the wort is simply not very fermentable. If the yeast strain secretes starch-degrading enzymes, like “super attenuators,” things will be different.

My advice about yeast strain is to select yeast strains that produce good beer flavor in the normal temperature range of your brewing shed. For the sake of discussion, assume that your normal temperature is 76 °F (24 °C). With that knowledge in hand, go look for strains that are described for working well at this temperature. You can further refine your search by nailing down the style of beer you want to brew and looking for a strain that works for the style and your temperature norm.

Q
After reading some previous articles on making cider, I’ve decided I’d like to give it a try. But I have a couple of questions:

1. I am going to try aging in 5 quart (5 L) barrels I found and I love the idea of using the malolactic bacteria (ML) culture to round out the flavor — do I have to use a regular white wine yeast and then add the malolactic bacteria later in the barrel or can I use only the ML?

2. I want a greater depth in flavor in my cider (hence trying to use a barrel to impart a vanilla/ toasted oak flavor to the cider). A second idea I had was to age bourbon/ whiskey in the barrel for 4-6 weeks (almost as an extended conditioner for the barrel), then rinse clean and age the cider in the barrel after that. Any thoughts as to the flavor the whiskey soaked barrel will add to the cider and/or damage that will cause to the fermenting process?

3. I love clean crisp ciders, but on occasion, a more malty mouth finish is wonderful. How can i impart such a finish on a cider?
Talor Migliaccio
Colorado Springs, Colorado

A

Cider certainly has become quite popular in recent years and with the popularity has come many very nice ciders on the market. In my opinion this is all the more reason to make cider at home to share with friends and family and to play around with ways to further explore the complexity and nuances of this great beverage. The questions that you ask about are certainly good things to consider.

Apples contain a fair amount of malic acid and this acid provides tartness to apples and other fruits. In fact, the name malic acid comes from the Latin root “malum,” which is both the root for apple and evil. That opens up some interesting naming ideas! Since ciders, like grape wines, have the tendency, depending on yeast strain and fermentation method, of fermenting out very dry they can become very tart.

The tartness in dry ciders can border on the extreme, especially when the juice blend contains a lot of tart varieties or is from a single, tart variety like Granny Smith. The use of so-called malolactic strains of bacteria, such as Leuconostoc oenos, is a nice way of rounding out these tart ciders. During the malolactic fermentation, often referred to as “ML fermentation” or “MLF” by the cool kids, malic acid is converted to lactic acid. Since lactic acid has a much softer acidity than malic acid, the result of the MLF is a rounder cider. These bacteria also produce diacetyl and ciders and wines that have undergone MLF often have a pronounced buttery nose and silky palate. I personally like the flavors and aromas associated with MLF and believe that the process adds complexity.

OK, so a few pointers. The ML culture does not replace yeast. You will still need to use a winemaking or brewing yeast strain for the primary fermentation. You can add the ML culture to your must along with the yeast, or you can add the ML culture after the primary fermentation has completed. This is a weighty topic and there is a lot of information written about MLF in the wine literature. There are many different types of bacteria that can be used and different strategies on when to add them and how to control the MLF. This is definitely something worth playing with!

Oak aging is another thing worth playing with. Cider is wine and the same basic techniques used to make grape wine can be applied to making cider. I have aged ciders in new American oak barrels and the results have been pretty exciting; almost like low alcohol white wine. I think the thing you need to be careful about is imparting too much oak flavor, and this is especially true if you are using new barrels. Oak spirals can also be used, and one of the benefits to spirals is the ability to reduce the oak area to cider volume ratio. Another way to accomplish the same thing is by blending cider aged in oak with cider aged in glass or stainless steel. This is a matter of taste.

I do like the idea of aging cider in whiskey barrels and think you will be happy with the flavor contribution. One thing to consider is that whiskey barrels have an interior char that makes the wood like a sponge. This is why aging beer or cider in a wet whiskey barrel increases the alcohol content. Wine barrels have a much smoother interior finish and the wood is not charred. Although wine barrels do retain liquid when they are hydrated, the flavor transfer will not be anywhere as intense as when using a whiskey barrel. The barrel flavor itself will also be much different and a wine barrel is likely to primarily impart vanilla and toasted oak flavors, whereas a whiskey barrel, especially a wet whiskey barrel, is going to give these flavors plus others like coconut, leather, tobacco and, of course, whiskey.

The thing about aging cider in a wet barrel is that the process adds alcohol to the cider. Since, in the US, this process is controlled by the alcohol tax regulators most commercial ciders do not use such methods. But making cider at home opens the door to a lot more process freedom. If the primary purpose of the barrel aging is to impart whiskey/bourbon flavors and you are able to use a whiskey barrel, you do not need to wait very long for the flavor transfer to occur. Many excellent whiskey barrel-aged beers spend 4-6 weeks in the barrel prior to packaging. Just to be clear with my basic advice, you should be adding fermented cider to the barrel for aging and top the barrel up as much as possible to minimize the headspace.

And your last cider question is about adding maltiness to the finish. The most direct way of addressing this desire would be to add some wort to your apple juice before fermentation. In fact many ciders on the market contain some fermentables from malt so that they are taxed as beer and not wine. One of the challenges with cidermaking is having some residual sweetness and using wort, especially wort with a fair bit of crystal malt, is one way of boosting the finish gravity of the cider and contributing that maltiness that you seek. As with brewing, you do want to boil the wort to kill bacteria but unlike beer brewing you don’t want to add hops.
Another way of increasing body and making cider that tastes more like apple juice is to stop the fermentation before it comes to completion. Many commercial operations use pasteurization for this, some stop fermentation by rapid chilling and others add preservatives such as sulfites and sorbates. Another method is to ferment the cider dry, back-sweeten with unfermented juice and then pasteurize. If I were looking to make a sweet cider I would want to use pasteurization because that is really the most reliable method.

Q
I am making the switch to all-grain and got curious about the pH of our well water here. So I got some strips from my local shop just to get a rough idea of our water pH. Well it came in at about 4.6. A friend came by with some buffer (his pH tester was on the fritz) and sure enough the strips did not lie. So how and what do I use to get the water up where I need it? Just about everything I read is about adjusting down, not up.
Steve Sokoloff
Sweet Home, Oregon

A
This is a question that I have never been asked and did a little digging. The reason for the digging is the very low pH of your well water. Most well water ranges in pH from about 6.0 to 8.5, and the EPA has published guidelines indicating that the pH of well water should fall between 6.5 and 8.5 because when the pH of water is out of this range it is due to something that may be of concern from a health and safety viewpoint. You really should contact your local water district, even if you are not on a municipal water supply and ask about what is normal in your area.

One real problem with acidic water is plumbing corrosion. The pH of groundwater varies based on the minerals present in the earth and low pH water is not necessarily an indication of a big problem. In fact many regions of the country have low pH and municipal water utilities adjust water pH by adding alkaline solutions, such as sodium hydroxide, to increase the pH to about 8.5. The reason for doing this is to prevent corrosion of pipes caused by acidic water. If your home well water is consistently low your pipes will be damaged over time.

So onto your question about water pH and mashing. The first thing to note about water is its buffering capacity, or its resistance to pH change. All buffers are considered weak acids where an acid component and a base component that are in equilibrium; these two components essentially remove hydrogen and hydroxide ions that are added to a solution and by doing so stabilize changes to pH that would ordinarily be observed when these compounds are added to a poorly buffered solution. The most common buffering system in water is dissolved carbonates and water that contains carbonates will resist changes in pH more than water that has essentially no buffering capacity, for example distilled water.

The second thing to note about pH and brewing is that malt is rich in compounds that are buffers. The two most significant buffering systems added to the mash from malt are phosphates and proteins/polypeptides/amino acids (collectively called “protein”). The buffering capacity of mash is usually much, much higher than water. This means that mash water with a relatively high or relatively low pH may have very little effect on mash pH if the water is poorly buffered. But if the water has a high buffering capacity, as is the case with water high in carbonate, mash pH may end up being higher than desired (high mash is the result of carbonate water).

When brewing water is rich in carbonates the mash pH can be lowered by adding calcium in the form of calcium sulfate and/or calcium chloride to water. When brewing water needs to be adjusted for mash pH control, it is almost always because of carbonates. There are times, however, when the mash pH is too low and needs to be increased. In these cases carbonates are added to water. Calcium carbonate and sodium bicarbonate are two common salts used to increase mash pH, and an example of when these salts may be required are when brewing beers with a high percentage of roasted malts that tend to lower mash pH. Historically, this is why dark beers were brewed in regions with carbonate waters.

Note that in the discussion above I state that calcium salts can be added to mash water to lower mash pH and that carbonates can be added to increase mash pH. It’s the mash pH that is important and in the case of calcium additions the water pH is not altered by the addition because the acidifying effect on mash pH only occurs when calcium reacts with the malt buffer systems.

You need to confirm that you indeed have acidic water, and this may or may not be a concern for your home use. If your water is safe, you should also determine what happens when you use this water for mashing. The simplest and cheapest thing to do is to conduct a small test with about a quarter pound of malt. Just make yourself a small test mash in a pot and measure the pH. It may be that the mash pH is not affected by the water and all will be fine.

If your mash pH is lower than 5.2 and you want to increase your mash pH, you should consider adding sodium bicarbo-nate (baking soda) or calcium carbonate to your brewing water. These compounds will increase water pH so don’t be surprised if you are measuring water pH as part of your experimentation.

Issue: March-April 2015