Troubleshooting A Recipe, Beer Spicing, Using Sanke Kegs, and Priming A Keg

Q I just recently brewed what I would call a hybrid beer. It’s too hoppy to be a brown ale, yet not dark and roasty enough to be an American stout. The issue I have is I’m getting an off-flavor; an upfront bitterness of what I would call grapefruit or citrus pith.

When researching off-flavors I get nothing that relates to this flavor. I used three ounces (85 g) of Cascade hops at 4.4% alpha acids for bittering in a 45-minute extract boil, and two ounces (56 g) of East Kent Golding as aroma hops.’

I’m thinking maybe too much bittering hops. My beer is drinkable and when a side-by-side comparison is made with Shiner Bock and Negra Modelo, it is remarkably close in taste except for the upfront pith bitterness. It doesn’t last long; you taste it right away then it’s gone and doesn’t leave any aftertaste. Can you help me figure out where it comes from and what exactly it is?

Stephen Elliott
Lawtell, Louisiana

A Nice description of the character in your beer you don’t like. Before getting into an answer, I want to comment on how important good descriptions are when attempting to problem solve. Aromas and flavors are very often challenging to describe because we don’t perceive flavor and aroma as individual signals like an analytical instrument with discrete bits of information tied to different constituents; rather we tend to perceive aroma and flavor in a more holistic sense. Using the words “like” and “as” are really useful when researching how your beer, in this example, reminds you of grapefruit or citrus pith. We’ll come back to that point in a moment. When flavor issues are clearly identified, researching the thing you are reminded of is often a very useful endeavor.

Bitter pith — it’s interesting that you describe the flavor as bitterness similar to grapefruit or citrus pith because the primary cause of bitterness in citrus pith, or the white, spongy, albedo layer of the peel beneath the flavedo (pigmented outer layer) and the interior made up of juice sacs, is the flavanone glycoside called naringin. And the albedo from grapefruit typically contains much more naringin than other citrus fruits. I personally like the clean and intense bitterness from this compound and have a good idea of how your beer may be perceived.

Suffice to say, you think your beer is out of balance and is expressing an intense bitterness. Thanks again for the good details in your question; three ounces (85 g) of Cascade with 4.4% alpha acids yield about 40–45 IBU assuming 5 gallons (19 L) wort volume and 25–30% utilization. That last addition of East Kent Golding is a bit of a wild card, but if we assume 5% alpha and 5% utilization, we have another 7 IBU addition, and you are now sitting between 50–55 IBU. Let’s hold that number for a second.

OK, you are getting a sharp bitterness that you are also describing like the bitterness of grapefruit. That suggests that you are tasting more than garden-variety bitterness that one may get from something like aspirin or quinine. Seems that you may be picking up grapefruit aroma from the hop varieties you are using. This makes sense as grapefruit is an attribute of both Cascade and East Kent Golding hops.

Photo by Charles A. Parker/Images Plus

And now, let’s move onto the beer. Shiner Bock and Negra Modelo are both medium-bodied beers with little roasted malt characters and fairly low bitterness levels. According to the Spoetzl website, Shiner Bock contains 4.4% ABV and has 13 IBUs, and the Modelo website has Negra Modelo described as Munich-style dunkel weighing in with 5.5% ABV with no stated IBUs.

The good news with what you’re describing is that the unpleasant bitterness in your beer is related to intensity. Lingering bitterness is often associated with beers that are both astringent and bitter. Too bitter is easier to fix than astringency. Assuming my estimation of 50–55 IBUs is in the ballpark, it makes sense that your beer is too bitter for your objective of producing something akin to Shiner Bock or Negra Modelo. I would back my bitterness down to somewhere around 20–25 IBUs to be closer to the beers you seem to be targeting and also closer to the typical range of bitterness of the dunkel style. The Beer Judge Certification Program (BJCP) style guidelines for this style have the bitterness range set between 18–28 IBU.

You may also want to consider changing your approach to hops and select a variety or varieties that are not as bold as Cascade and EKG. I know some are laughing at that last sentence, but these varieties are bold compared to hops usually selected for use in malt-centric lagers. A variety like Magnum to do most of the heavy lifting coupled with a late addition of something like Hallertau Mittelfrüh, Tettnanger, Hersbrucker, or Mandarina Bavaria (a bit of orange and chocolate?) would be a conservative approach for the style.

My last thought is that you began your question by naming two ales, brown and stout, but compared your beer to lagers. When embarking on a new brew, it’s always a good idea to have a target in mind. And it’s totally cool if the target does not match your starting recipe, as long as you align your process with the target. If you really want to end up with a balanced, drinkable beer like the two commercial beers you name, but are using a hybrid brown ale/stout recipe, you will probably continue to miss your mark. Check out your water, malt selection, and yeast selection. Details, details! These are things that make brewing such a great hobby for the tinkerer.

Q I am planning to brew Dixie Cup Boardwalk Belgian Quadrupel from the byo website. I am wondering if I add spices and raisins at the end of the boil will there be enough time for the aroma compounds to dissolve into the wort before cooling with a plate chiller?

Sonny Lachance
Drumondville, Québec

A Flavor extraction is almost always influenced by particle size. Indeed, the only times this is not true is when the compounds of interest are not soluble in the solvent being used for the extraction. In brewing, there are really two solvents of practical interest. Water is the solvent at play during the production of wort, and beer, or water + ethanol, is the solvent when ingredients are added to beer. Crushing or milling spices is the best way to improve extraction efficiency of your spice additions and chopping or blending raisins will give more tang for the buck than whole raisins. And adding your spices and raisins towards the end of the boil should provide more aroma retention than adding with several minutes left of boiling. That answers the question and I don’t have anything else to say about that.

But there are two related things that are noteworthy. The first is about your wort cooler. Plate chillers, usually called PHEs or plate heat exchangers in commercial circles, are the most efficient heat exchanger type used for wort cooling for several reasons. The most significant aspect of the design of these devices is the surface contours of the plates. Although different plate patterns are used for various applications, PHE plates all resemble an old-fashioned washboard. The plates in a PHE are stacked up and flow paths through the plate pack are established by holes in the plates that direct coolant and product through the unit. Because the plates are closely packed, the liquid film is thin, and because of the shape of the plates, the flow is highly turbulent. These attributes, coupled with the minimal thickness of the plates, increase the overall heat-transfer coefficient, or U-Value, and make these heat exchangers very efficient compared to other designs, such as tube-in-tube and immersion chillers. Add a high surface-to-volume ratio to the relatively high U-Value, and the result is pretty amazing.

The design features that make PHEs highly efficient heat exchangers can also be a weakness. Bits and pieces of hops, malt husk, citrus peel, fruit skins, coffee grounds, macerated raisins, and coriander seed can all become trapped inside of a PHE. In extreme cases, these solids will clog the PHE and the problem is obvious. Yet other times, particles will reside in a PHE to simply become breeding sites for microbiological growth without having an obvious effect on wort flow. The take-home message is to keep particles out of your wort cooler.

The other point your question raises is about crushing or milling of spices and other ingredients like raisins. Decreasing the particle size of these ingredients will absolutely speed extraction, but it also changes the recipe. If you have been adding two cinnamon sticks at flame-out, for example, to brew a beer that you love, be careful before you decide to start milling the cinnamon because you will most certainly end up with more flavor from the cinnamon. You also need to be mindful that powdered spices are mainly composed of insoluble bits of bark, plant leaves, and seeds; these fine particulates tend to settle around low velocity areas in a heat exchanger and can begin to fill the PHE with particles similar to silt around a river delta. And that’s all I have to add about that point. Here’s to fun additions to wort and efficient wort cooling!

Q I am trying to determine if I should be using a Sanke keg instead of a regular pin-lock keg for a beer gas mixture (75% nitrogen / 25% carbon dioxide) that I am pushing at about 50 PSI. Although I have not checked every weak point in my system, I have replaced all the O-rings, bought a new lid, and have a new gas line. But I do have a gas leak somewhere. Are Sanke kegs inherently more reliable when it comes to leaking gas?

Robert Pritchard
Bridgewater, New Jersey

A One feature of reliable designs is the minimization of the number of parts that may fail and result in a problem with the device in question. The Sanke keg valve (from “sanitary key”) assembly has two elastomeric parts that are on the keg side of the system, and the Sanke coupler/tap that connects to the keg has five elastomeric parts (combination of O-rings and special seals).

The Cornelius-type (Corny) keg used by so many homebrewers has a total of eight O-rings on the keg side of the system and two O-rings on the coupler side. Yes, Corny kegs have more elastomeric parts than Sanke kegs, but two versus eight is a manageable difference, especially since the most important O-rings on a Corny keg are visible and easy to inspect. However, Corny kegs have a removable lid that is sealed to the opening in the keg by an O-ring, and this seal can be compromised if the lid or the shape of the sealing surface of the keg become damaged. My view on these designs is that they are both robust when viewed from a gas leak perspective.

Sanke kegs are designed to be cleaned without disassembly and require special cleaning equipment for this type of service. Some Sanke kegs do have threaded, removable spears that make disassembly and cleaning easier than the more common design of spear that is secured to the keg with a special split ring. Sanke spears must never be removed when a keg contains pressure because the spear can be shot out of a pressurized keg, resulting in severe bodily injury or death. The Sanke design is terrific for breweries with the correct cleaning systems, service tools, and training required to properly clean and maintain these kegs. However, very few homebreweries are equipped to clean Sanke kegs without disassembly; for this important reason, homebrewers are really best served, no pun intended, by Corny kegs.

Also remember that the opening on the top of Corny kegs can become bent, so you should inspect the uniformity of the lip.

OK, now onto the fun part of your question; leak testing! Keg leaks are fairly easy to identify in a binary manner because a leaky keg will eventually lose all of its pressure. Leak rates are very difficult to measure unless you conduct your test in a temperature-controlled environment where any change in pressure is due to gas loss, versus temperature change. Once you check the keg, you can begin expanding the size of the system to help identify what part of the system is leaking. Connections are the most common sources of leaks. And don’t forget to test your gas regulator assembly for leaks around all the threaded ports and connections to the regulator using soapy water or you could try submerging the regulator in a water bath to spot leaks. Also remember that the opening on the top of Corny kegs can become bent, so you should inspect the uniformity of the lip.

Replacing gas and beer lines is definitely a good start. You should also check the size of the hose barbs in your system to verify that all hose and barb connections are properly coupled. And then you want to ensure you have a secure fit. The clamp of choice among draft techs are so-called stepless, ear-type clamps. This clamp type was invented by Hans Oetiker in 1979 and named the StepLess® ear clamp. Trivia time! Oetiker founded his company in 1942, developed the first ear clamp in 1951, and his name is associated with his clever and reliable inventions. There are many other clamps based on Oetiker’s design used in a variety of industries.

The StepLess® design evenly reduces the clamp diameter when tightened with a crimping tool, while creating no sharp protrusions that can cut the tubing wall. The major downside of the design is that the clamp is not designed to be used more than one time; once an ear clamp is connected it must be destroyed to remove. Although the clamps are not expensive, they are a bear to remove. I am an optimist and view this as a good thing as it encourages the use of proper connections, like stainless steel, flared fittings with free-spinning nuts, in areas where tubes need to be attached and removed.

For what it’s worth, 50 psig (gauge pressure) is a much higher dispense pressure than the 35 psig of 70% N2 /30% CO2 suggested by Guinness for their quintessential nitro stout. Find those leaks and enjoy a nice pint of your nitro brew!

Q When using priming sugar in a keg, as opposed to bottles, do you need to reduce the amount of sugar? Some blogs suggest by one third.

Ian Woodman
Bradford, England

A This is one of those rules of thumb that always makes me scratch my head. Bottle, keg, and tank- conditioned beers all contain carbon dioxide from a combination of the CO2 remaining in beer following fermentation plus the CO2 derived from secondary fermentation. Assuming that bottles, casks, and tanks all scale up proportionally, the vessel size in which beer carbonates has no effect on carbonation level when the same priming rate is used. For example, 10 grams of dextrose added to 1 liter of beer will always yield about 4.9 grams of carbon dioxide per liter beer when fully fermented during secondary.

But bottles, casks, and tanks do not scale proportionally because these different types of beer containers have different headspace volumes. A half-liter, flip-top beer bottle has a gross volume of about 510 mL, equating to 2% headspace. My 5-gallon Corny keg has a net capacity of about 19 L with 740 mL of headspace; that translates to about 4% headspace (this is voided though if you pressurize the headspace of your Corny to properly seal the lid shut). Most lagering tanks in commercial breweries have at least 10% headspace and cylindroconical fermenters usually have about 30% headspace. The assumption that a vessel is a vessel is clearly not true. So, how does this factor into the rule of thumb that keg-conditioned beer should be primed at a reduced rate compared to bottles?

If the objective is to produce the same volume of CO2 per vessel volume, this rule of thumb is backwards because priming rate increases with headspace volume. No argument that this rule of thumb has been around for decades. Why? My take has always been that bottled beers with between 2.5–3.0 volumes of CO2 (5–6 g/L) pour nicely with a proper crown of foam. But, when these same beers are dispensed on draft, care must be taken to prevent excess foaming; truth is, that it’s much easier to pour draft beer with less CO2. Not the most exciting revelation, but an explanation of why draft beer sometimes contains less carbonation than the bottle equivalent. The other thing to consider is that much of what we do in homebrewing is rooted in British brewing because homebrewing as we know it today spread from the U.K. to the U.S. in the late 60s, and cask ales, with low CO2, ruled supreme during that time.

If your preference is to condition by secondary fermentation, you are going to be a happier brewer if you are able to measure or weigh the amount of beer you are conditioning and calculate the dosage rate of priming sugar accordingly. If this is not practical or seems too chemistry lab for you, my go-to suggestion is to over-prime in a keg and control carbonation level with a spunding valve.

Issue: July-August 2021