Cleaning Wort Chillers, Mash Hopping: Mr. Wizard
Q
I’m Requesting your advice for cleaning and care of copper wort chillers. Like other brewers, after the cool down I pull my wort chiller out of the pot and it’s usually covered with stuck on grain and hop residue. I put mine in a tub and wash it with dish soap using a brush or cloth. It’s difficult to get between the rings properly. It has been suggested that I can put it into my dishwasher for cleaning, but I’m worried the liquid in the rinse cycle may damage copper.
Ray Snyder
Kelowna, British Columbia
A
Copper has some excellent properties that make it great for brew kettles and wort chillers. Copper is a superb conductor of heat and is highly malleable, which means that it can be easily formed for use where thermal conductivity is important. Copper is not pure and contains a small amount of zinc. It’s also soft and does dissolve over time, which means that copper contributes copper and zinc to wort. Zinc is a micronutrient and is beneficial to yeast growth and metabolism and copper binds sulfur formed in fermentation.
The downside to copper is that it is soft and dissolves over time, even when it is treated with great care. This is why old copper kettles eventually wear out. Many breweries with copper kettles and mash mixers replace the copper bottoms with stainless steel because copper is expensive and not easily repaired, especially as the number of skilled coppersmiths continues to decline. These breweries use specialty cleaning chemicals containing corrosion inhibitors so that strong alkaline cleaners, principally sodium hydroxide, can be used for cleaning. Acid cleaners are also commonly used to clean copper.
You can certainly clean your copper wort cooler with mild dishwashing detergents and a gentle scrubbing pad. Mild abrasives can also be used on copper. Some commercial breweries use a diatomaceous earth (DE) and yeast residue removed from filters to clean copper. The DE is a fine, very abrasive, similar in texture to the perlite (volcanic ash) used in toothpaste, and the yeast and residual beer is mildly acidic. This stuff really works well and is a nice way of turning a waste product into a handy cleaner.
Oxalic acid cleaning powders, such as Bar Keepers Friend, are very effective metal cleaners when used as a paste. Simply cover the copper coil with a mixture of oxalic acid powder and water made up to a thickness of hand lotion, allow the mixture to sit on the surface for about five minutes, wipe with a soft towel to gently scrub and rinse well with water. If your coil is too tight you may want to consider opening it up a bit to permit easier cleaning, or use a soft brush to help get into the small gaps of the coil.
As a side note, oxalic acid powders also work very well to clean stainless steel. Care must be taken when cleaning polished stainless with any type of abrasive because the surface appearance is easy to change. Also, polish in the direction of the grain.
I would stay away from the dishwasher unless you really know about the detergent you are using. Many dishwashing detergents use chlorine bleach to help remove proteins, and chlorine pits copper. Some dishwashing detergents contain alkaline components that can also damage copper. The thing about most household cleaners is that it is very difficult to know all of the stuff contained since the blends are proprietary. Another thing to consider is that no manufacturer of copper cookware recommends washing in a dishwasher because of the potential damage that can occur. That’s a pretty good reason to avoid the dishwasher!
Perhaps one of the handiest features of copper immersion chillers is that the entire coil can be boiled prior to
use. Dr. Michael J. Lewis, the famed UC-Davis brewing guru and my mentor, is known for his wit and oftentimes blunt descriptions. “You can sterilize dog s—t, but that does not make it clean.” This was Dr. Lewis’ explanation of the efficacy of heat sanitation. So even if your copper wort chiller is not immaculately cleaned, immersing the coil in boiling wort for 20 minutes or more will kill any microorganisms on the surface.
Q
I’m looking to enter a few of my homebrews into a festival and I’m unsure about how far ahead of time I can keg. I’m still a little new to kegging so here are my questions: How do I keep the carbonation without over-carbonating? Do I leave it hooked up to the gas until I’m ready to serve it? What should pressure be set at if I have to leave it hooked up? Does it have to be kept cold?
Michael Aughinbaugh
Hanover, Pennsylvania
A
Kegging in a simplistic sense is not much different than bottling. The biggest differences between a keg and a bottle are the size of the container and how the beer is removed from the container.
The thing that helps the most at home to ward off oxygen is to take advantage of being small with few batches to deal with. At home it’s easy to fill a clean keg with water, push it out with carbon dioxide and rack beer into an environment that is virtually oxygen-free. This one thing really helps address oxidation.
The next step is handling carbonation. Whether you keg condition or force carbonate, you begin the process in the keg. If you keg condition you want to add priming sugar, and perhaps yeast, prior to keg filling. If you force carbonate, no preparation before kegging is required. Suffice to say, at the end of the carbonation process you have a keg of carbonated beer.
If you are planning on force carbonating the beer, you need to be aware that the pressure which you apply the CO2 via the regulator is dependent on two factors. The first factor is what temperature the beer is being stored in. The second factor is the carbonation level you plan for your beer. So let’s take a look at these two factors.
One of the basic laws of chemistry is Henry’s Law. The basics of Henry’s Law state that the solubility of a gas in a liquid is dependent upon the temperature, the pressure of the gas over the liquid, and the nature of the gas and liquid. Carbon dioxide increases in solubility in water as the temperature decreases, as do most gases. So the colder the beer is kept, the less pressure is required to “push” carbon dioxide into the beer.
Next you need to determine the final desired carbonation level of the beer when serving. Often times homebrewers will reference guidelines based upon the style of beer they are serving. While a standard for most of the craft brew world might be serving beer at about 2.5 volumes of CO2, that often changes. Bavarian hefeweizens often will be served at 3 volumes of CO2, Belgian tripels may contain over 3.5 volumes of CO2, while a British ESB may only contain 1.8 volumes. Determine how much carbonation you want your beer to contain, but be aware that you may need to increase the length of the serving lines of the beer to handle highly carbonated beers. Balancing draft lines is a whole other question (but you can find a lot of great information on the subject in this story from the January-February 2006 issue at https://byo.com/story164).
You can find carbonation charts to help guide you on where appropriate carbonation levels may fall for different beer styles through a simple search on the Internet. But let’s take an example. Say you brewed an American pale ale and are looking for a carbonation level of 2.4 volumes of CO2. If you are planning on force carbonating the beer up near room temperature, say 65 °F (18 °C), then you would need to set your regulator to 29 psi to achieve that level of carbonation.
An important thing to keep in mind is that once the carbonation is balanced, then it is balanced. You can leave the CO2 on at 12 psi at 40 °F (4 °C) for two years and still have 2.5 volumes of CO2 in your beer. Because the pressure of the CO2 in the beer equals the pressure of CO2 in the headspace above the beer. When dropping the temperature of the beer from 40 °F (4 °C) down to 32 °F (0 °C) without changing the regulator from 12 psi, you will effectively change the carbonation level from 2.5 volumes of CO2 in the beer to 2.9 volumes of CO2. So if you plan on leaving the gas hooked up until you are ready to serve, be sure not to change the temperature of the beer. If you need to place the keg in a warm or cold environment, simply remove the gas line of the already balanced beer and you will not cause an unbalance.
And what should happen next to prolong the life of your keg of homebrewed perfection? Well, that depends.
Assuming this beer is not keg-conditioned and was relatively clear and ready to drink (minus carbonation) prior to kegging, the best thing to do with your beer is store it cold prior to tapping. Just like well-crafted beer from a brewery without a pasteurizer, your kegs of homebrew can last for months before tapping.
If the beer is keg-conditioned you need to hold the keg warm just like bottle conditioned beer to allow for package carbonation/conditioning to occur. And if the beer can benefit from further conditioning, you may want to store the beer cool, but not cold. View your keg just like a bottle. If the bottle is the type of beer that will improve with cool (not cold) storage, do the same with the keg.
Whatever you do, avoid the temptation to pull samples from your keg and disrupt the balance of things. This can be done without causing problems . . . but . . . you stated that you are new to kegging and are stockpiling beer for a special occasion.
There are several factors influencing shelf life, so I will give some sweeping generalizations to shed a thick fog over this weighty topic! Beer that is filled in such a way to minimize oxygen pick-up and stored cold will taste pretty darn good for 120 days without any major issues. But if this beer has microbiological issues all
bets are off. Contaminated beer can develop off-flavors even when stored cold, so this introduces a big wild card into things.
The other major issue is oxygen pick-up during packaging and other steps in the process where beer is moved from one container to another or when oxygen can be introduced, such as dry hopping. Packaging is the main concern for oxygen pick-up. The old adage “easier said than done” is alive and well when packaging beer in kegs, cans, and bottles.
Q
When mash hopping, do you need to add the weight of the hops into the grain bill water-to-malt ratio? Or is the amount of hops really not a factor here, even though the hops will take up an amount of the water added to the mash?
David Comer
Utica, Michigan
A
The direct answer to this question is no. Hops do not need to be figured into the water-to-malt calculus. This ratio is used to determine strike water temperature and has a real effect on mashing enzymatics and first wort gravity (important when considering really big brews). In a nutshell, malt weight and mash thickness influences wort volume and wort gravity. Wort yield into the fermenter is another story.
Pause the hop button for a moment. Wort production sets the stage for finished beer. Conversion of starch to fermentable and unfermentable carbohydrates, extract yield, and pre-boil volume are all related to what happens during mashing. Changing mash thickness and mash temperature can be used to influence wort fermentability.
Adding hops to wort in the kettle or beer in a fermenter only influences what the hops contribute. In the brewhouse, more hops will yield more bitterness and possibly more aroma. And these same hops detract from wort volume because they soak up wort and increase waste.
Wort loss is not easy to calculate in general terms because brewhouse design and hop type do not have the same effect on all brewhouses. The bottom line is that hop additions do indeed influence your batch yield as wort losses generally increase with hop addition rates. When brewing beers with high loads this loss is often anticipated so that the net batch volume is in-line with needs.
Q
I have read that marijuana and hops are closely related. With the legalization of marijuana on the rise in the United States, do you believe that it will soon begin to be added to beer? If so, how, and what impact would it have?
Devon Rollins
Beaverton, Oregon
A
Let’s get one thing clear, legalization of marijuana has absolutely nothing to do with this topic. Seriously. I can’t believe this question is being asked by a resident of the greater-Portland area! There are possibly more funky bars, cafes, and 60s-themed venues in Portland than in San Francisco. I think folks have been adding hops’ only cousin to beer for quite some time.
My opinion on this subject is based on beer labeling laws in the United States. I really do not think we will be seeing giant waves of Canabinales and Skunkweed Pilsners flooding any markets because beer labeling is primarily controlled by the Alcohol and Tobacco Tax Trade Bureau, or TTB. Although a brewery that only sells beer within the borders of the state where the beer is brewed does not have to comply with federal labeling rules, most states have laws that are consistent with TTB rules or simply defer to TTB approval. And labeling laws do directly address what ingredients are being used in the beer, even thoughingredient lists are not required on beer labels.
I live in Missouri and our beer labels require TTB approval for all beers sold in the state. I don’t know if this is true in all states, and it is possible that some states have different laws that may make things different. The practical point is that for states like Missouri, commercial breweries cannot do anything that is prevented by the TTB. Since marijuana is not legal at the national level, breweries cannot add marijuana to beer. So don’t hold your breath too long waiting for this type of beer to show up in the market.
I don’t think you want to be bored with all of this legal stuff, so let’s just rip the Band-Aid off and get to the nitty gritty. You can add marijuana to beer just like hops. Mash pot, kettle pot, whirlpool pot, dry pot, Randall pot-infused, pot oils, etc. If the brewing method includes the word “hop,” simply substitute with pot and you are good to go! You can play the same game with food and replace aromatic herbs with marijuana sprinkles with fun beer and food pairing experiments. How about a highly aromatic German Pilsner paired with a Pizza Marijane. The mechanics of this process seem pretty easy, so I will leave the creative development to others!
One thing is for certain, as brewers continue to push the envelope there will likely be some holes formed in the bubble that defines beer. I was discussing this very topic with a fellow brewer at the Master Brewers Association of the Americas (MBAA) annual convention in Jacksonville, Florida back in October. The concern that some brewers have is that a beer is sold that ends up making consumers sick. If this were to happen things would probably change very quickly.
