The Not-So-Great Hop Fade, Step Mashing, and Frozen Fruit

I typically purchase hops a pound (0.45 kg) at a time and usually a year old to get a bargain. Therefore, the bulk of my hops are about 2 years old. When I open the hops I break them down into 1-oz. (28-G) bags that I then vacuum seal.

I like making New England IPAs with the usual suspects: Citra®, Simcoe®, Mosaic®, etc. I have noticed that over my past handful of batches that the initial huge aroma blast I get when kegging the beer has usually subsided by the time it finishes carbonating (~1 week to carbonate). No matter which hops, no matter which combination of hops, they all fade to a “berry” aroma (tropical no longer exists) before becoming what I describe as a muted, lackluster mess. I don’t drink them as they aren’t what I am expecting. The beer itself doesn’t seem to have flaws.

I have been scratching my head and can only think it is due to the age of the hops. On brew day the hops smell wonderful prior to putting in the beer. When kegging, they typically smell great. But a week after being in the keg . . . done! I have successfully made many New England IPAs in the past and I have been brewing for 10+ years, so I think my overall process is good. I have been cold crashing by placing the carboy in the freezer for 24–48 hours prior to kegging.

Chicago, Illinois

Question and answer columns can be really frustrating for the writer when a question seems totally answerable until details within the question get in the way of the answer. Pesky details! This question contains a few of those gems. There are a few ways around this problem. One sneaky way is to carefully edit the question so that certain details don’t interfere with the answer the columnist wants to write, but I am not a big fan of this technique. Another option is to avoid questions that cannot be answered! After all, what is the use of replying to a question with a failing answer? And perhaps the most common stylistic choice is to use a very thin slice of the question as a launching point into something more interesting to the author than the actual question. Zinnng, off on a wild tangent!

And here I sit, looking at a question that has shut down all of the obvious answers. Scot, I see that you and your friend Rich are the two dudes behind the website called, uh, Two Beer Dudes, and that you have been brewing for 10+ years, have successfully brewed many New England IPAs in the past, and seem to have your brewing game on. It seems to me that you may not actually have a brewing problem! This brings me to the wild tangent option of the Q&A columnist, but in your case I am going to turn the mirror perpendicular to the question and review some of the things that may help others brewing this style and just hope that I stumble onto something that may also help you!

Repackaging hops into smaller sizes is a good idea when buying hops in larger quantities because oxygen in the package does cause storage problems.

So let’s get this party started. Repackaging hops into smaller sizes is a good idea when buying hops in larger quantities because oxygen in the package does cause storage problems. The polymers used to make food-packaging materials may or may not have gas barrier properties that slow or essentially prevent the movement of oxygen molecules across the liner. Just because a vacuum packaged bag of hops feels rigid does not mean the packaging film is impervious to oxygen diffusion. Probably not a likely cause, but perhaps you changed the packaging materials and your hops are being oxidized during storage. I know, the hops smell wonderful, so this cannot be the problem.

Another possibility is that your hops are not as great as you think they are. Properly packaged and stored hop pellets can maintain high brewing value for a several years. The fact that you are buying year-old, or perhaps older, hops is not a big red flag. And you firmly shut down that avenue by describing the hop aroma as “wonderful” on brew day and as “typically great” when kegging. I am assuming that brews from atypical kegging days, you know the ones when your hops smelled like yesterday’s running socks, are not the same brews that you are not loving.

Call me Mr. Obvious here, but you are brewing really hoppy beers and don’t like the way hops are expressed. Humor yourself and brew the same beer with the same hop varieties from another source than your hop locker. Just because these hops smell great doesn’t mean that your finished beer will meet your expectations.

It’s impossible for me to make any assessment about the quality of your hops from the comforts of my home office, but hop quality is a likely candidate to your displeasure. Brewers hear and speak about how terroir affects hop aroma and how hops are expressed in beer, but most hops that brewers buy only have 3–4 pieces of information on the label: Variety, harvest alpha, crop year, and total oil. Commercial brewers can obtain more information than this, but usually only after requesting the information.

Homebrewers who purchase hops in bulk should look to repackage open hops bags using a vacuum sealer. Be sure to label them though!

My point is: Don’t assume that all “Crop year 2016 variety X” hops are the same because they probably are not the same. Different farms, even within a single valley, can yield different hops simply due to terroir. Add agricultural practice, harvest date, kilning method, pellet processing method, and packaging technology to the mix and it is easy to see why “Crop year 2016 variety X” is an extremely vague way of viewing what is in the bag. And this is all before the hops ever get close to your re-packaging operation. How were these hops stored between the time of packaging in the fall of 2016 and when you purchased them? And how were the hops handled during shipping? Did the hops leave the warehouse on July 3, a Wednesday this year, and deliver to your home on Monday, July 8? That shipping scenario means that your hops were probably baking in a shipping warehouse or in the trailer of a truck for a total of 5–6 days. Not saying that this is the problem, but brewers should always suspect hops when the brewing problem is hop aroma.

Moving onto some other ideas; have you changed yeast strains or sources? Since much of the “juicy” notes attributed to this style are intertwined with biotransformation, it could be that you have done something related to fermentation. Make sure you are using a yeast strain that is reported to biotransform hop terpenes and that you are adding your hops during, or shortly after, peak fermentation.

My last thought about your dilemma has nothing to do with brewing and has to do with the mirror I mentioned earlier. Perhaps the problem is that your expectations of the beers you have been brewing have become separated from what you are actually brewing. I have been in this spot before where I have had some abstract target in my head that I should be nailing but for some reason my darts are not even landing on the board. Tweak this, tweak that, and add a pinch more of the theme ingredient. It all comes up short. In times like these, the best thing to try is a total reset. Look forward, not behind, and start from scratch. If that doesn’t work, find a commercially-brewed beer that lives up to the flavor in your head and learn everything you can about that beer. Your problem really may be misalignment of expectations . . . or it may not. If your goal was to stump the chump with your question, you succeeded!

Whenever I’ve sought online advice for adding fresh fruit into a secondary, people consistently recommend using frozen fruit. I’ve used pasteurized purees, vodka-infused tinctures, and artificial flavoring, but those methods alter the flavors. I understand lowering the temperature will slow yeast growth. But does it actually kill off the baddies? Hollywood has taught me that freezing an organism, even for thousands of years, and thawing them out will result in disastrous monsters. I’d like to know the scientific answer, is there a chance anything would survive freezing?

Brad Carpenter
Raleigh, North Carolina

Hollywood movies generously apply dramatic license in all matters of the world. But when it comes to portraying the resurrection of frozen life forms, there is not much exaggeration when the organism is something like a bacterial or yeast cell. And most of us kind of know, perhaps without really knowing it, that freezing is not a form of sterilization. Let me give you an example. A pound of ground chicken is popped in the deep freeze and stored for 30 days at -40 °F/-40 °C; are you feeling eager to try some chicken tartare when this package is thawed?

OK, this is not an answer to your question, but you get my point. Freezing food may reduce microbial populations, but it is certainly not a substitute for pasteurization. In fact, freezing is a really great way to preserve cell viability as long as the cells or tissue being frozen are protected from the damaging effects of ice crystals with a cryoprotective compound, like glycerol, that interferes with the formation of ice crystals. So freezing yeast cells can actually be used to prevent cell death.

When it comes to brewing with fruit, today’s homebrewer really has quite the array of options. Many brewers find it hard to resist going au naturale and simply adding clean, damage-free fruit to beer. Fruit additions are usually made after primary fermentation is complete; not sure why this is, but the fact that the concentration of fermentable sugars is low is certainly a help when it comes to minimizing the growth of wild yeast. Spoilage bacteria are still able to grow in beer, but if the fruit is added to a sour beer, the bacteria and yeast on the surface may not be a problem. Clean beers, however, may be contaminated by this process and brewers wanting to use fresh fruit can use sulfite to knock back wild populations.

While going au naturale is attractive to brewers who like the romance of using fresh fruit or who simply want to use locally-grown fruits, many brewers either don’t have access to the right types of locally-grown fruits or don’t want to risk ruining beer with a potential source of spoilage organisms. This is where products like aseptically-processed purees, fruit extracts, and even crystallized fruit juices come in handy. While thermal processing can certainly change the flavor and color of fruit juices, it is also possible, and quite common, to thermally process fruit juices without negatively altering flavor. Single-strength citrus juice is a great example of how gentle pasteurization can be on juice flavor; seriously, few consumers are even aware that these products are pasteurized. Another option is to simply add the fruit at the time of serving. Lots of options, indeed.

Spoilage bacteria are still able to grow in beer, but if the fruit is added to a sour beer, the bacteria and yeast on the surface may not be a problem.

There was a time when many US craft brewers were living life on the lunatic fringe and throwing caution to the wind. After several brewers had very costly, barrel-aged beer recalls due to spoilage in the market, a good chunk of craft brewers adopted a more conservative and reasoned approach to packaging beers that potentially could cause problems months after leaving the brewery. Flash-pasteurization prior to bottling is no longer an unusual method, nor is it frowned upon by “cool brewers,” and the polymerase chain reaction (PCR) method of DNA amplification is now routinely used in brewing labs of all sizes as a rapid method to detect the presence of a wide range of beer spoilers before aged beers get anywhere close to being packaged.

Brewing with fruit opens up another chapter of flavor opportunities to an already impossible number of ingredient permutations. The risk of contamination is real but also realistically managed through fruit selection, time of addition, and brewing technique. Thank you for the great question and viva la fruta!

Step mash recipes usually have details about step temperatures and times, like the following example. Use a mash schedule with a 15-minute acid rest at 113 °F (45 °C), a 15-minute protein rest at 126 °F (52 °C), a 20-minute beta-amylase rest at 145 °F (63 °C), a 20-minute conversion rest at 158 °F (70 °C), and a 10 minute mash-out rest at 167 °F (75 °C).

  1. In a system with a heated mash tun, do we count the time it takes to get from one temperature to the next?
  2. In a Brew-In-A-Bag (BIAB) system, adding hot water can jump the temperature quicker, but would lead to shorter overall mash time. Isn’t that going to affect the result?

Mike Boesen
Fort Collins, Colorado

Let’s start out with two quick answers to your questions. Heating time is definitely an important part of the mash and it most certainly should be counted. In fact, control over the heating rate is often overlooked as a tool in the brewer’s arsenal of methods to wrangle the enzymatic changes that occur during mashing. This means that quickly heating any mash using hot water aliquots, whether BIAB or an unrestrained mash in a pot, may result in a different wort compared to slower heating using an external heat source (yes, this is difficult in the BIAB system). The question that this all begs to be answered is what mashing profile should be used and how do practical brewers select their mashing method and/or temperature profile when formulating a new brew?

The answer to this question really begins with the Snickers bar story and the concept of malt modification. When pondering mashing, keep in mind that mashing is an extension of malt modification plus the totally separate enterprise of starch conversion. For practical brewing purposes, starch conversion falls under the purview of the brewer, while malt modification can be a shared responsibility between maltster and brewer. Onto the Snickers bar story . . .

Professor Michael Lewis, the venerable and now retired brewing scientist from UC-Davis who mentored so many brewers, likened the cross-section of barley kernels to Snickers bars. The chocolate of a Snickers bar is the husk of barley, nougat is the protein, beta-glucan, and arabinoxylan matrix of the endosperm, and of course the peanuts are akin to starch granules. During malt modification, enzymatic degradation of the nougat exposes the peanuts and makes the endosperm of the malted barley easier to bring into solution during mashing, and also makes wort separation easier during wort collection. As it so happens, proteolytic and cytolytic enzymes, the enzyme types responsible for the digestion of barley’s nougat-equivalent, are more heat labile than amylolytic enzymes — responsible for peanut digestion.

What this means in practical terms is that the job of digesting the nougat is best performed by the maltster. This is why a majority of the lab analyses performed on malted barley relate to modification; soluble protein, the Kolbach index (soluble protein/total protein ration), total beta-glucan, friability, fine-coarse difference, and acrospire length are all indices of malt modification. Brewers using under-modified malts need to pick up where the maltster left off. Not all brewers have a problem with this deal and there are some brewers who prefer using lightly modified malt because of the control they retain over wort composition.

Most base malts these days, even a large percentage from continental Europe, are being malted from barley varieties that produce evenly- and well-modified malts that function admirably when infusion mashed. This is especially true of malts produced with the craft brewer in mind because a large proportion, probably the majority, of craft brewers have infusion brewhouses. Even breweries with the ability to perform multi-temperature step mashes have empirically determined that mashing method does not make much of a difference to finished beer when well-modified malts are used to brew all-malt brews. I do want to clarify for all you step- and decoction-mash devotees that I am not arguing that mashing method is irrelevant. I am just making this point for modern, well-modified malts.

Going back to the question I posed earlier; how does a practical brewer choose mash technique? This decision has been made much easier over the last 20 years or so as malts have become progressively better suited for infusion mashing. Many brewers today simply use the infusion method for every brew, and don’t vary mash thickness, mashing time, or mash temperature from brew-to-brew. Other brewers hang onto step mashing methods even when using modern malts because these brewers have “always” used these mash methods. I confess to being one of these brewers until about 2002 when I started questioning why I was doing things a certain way and began simplifying and shortening mashes. Then there are brewers who really go about matching mash method with their raw material. These brewers brew the most beer by volume, but they fall into the minority of brewers because of the lab methods required to really align mashing, raw materials, and wort/beer properties.

It’s taken a lot of words to provide a little contextual argument to the real message; don’t get too hung up on matching another brewer’s mash profile if you know how to deal with a variety of grist bills in your set up. To paraphrase Charlie Papazian, take a chill pill, sip on a chilled Pils, and don’t sweat the details!

Issue: November 2019