Hop creep

CREEP is a new 9% DIPA from us. With this one, we wanted to create a fuller bodied DIPA with some intentional residual sweetness without adding lactose. **CREEP DOES NOT CONTAIN LACTOSE!** We then added a ton of whole pumpkin pies to the mash resulting in a subtle flaky pie crust character with the slightest hint of pumpkin pie spice. Then we hopped CREEP intensely with Enigma, Motueka, and a touch of Citra hops. https://www.beeradvocate.com/beer/profile/41018/309842/

Luister ook eens https://www.youtube.com/watch?v=oQ7UsGzcfPc Al vind ik die wel minder dan het origineel: https://www.youtube.com/watch?v=k3_RU30tEIE

Creep is een single van de Britse alternatieve rockgroep Radiohead. Het nummer werd in 1992 uitgebracht als hun debuutsingle. Een jaar later verscheen het als albumnummer op Pablo Honey en werd het opnieuw als single uitgegeven. De Britse radiozender BBC 1 weigerde het liedje te spelen, omdat het zo deprimerend was. De groep wist er toch de zevende plaats in de UK Singles Chart mee te bereiken. Door het succes van Creep werd Radiohead aanvankelijk gezien als eendagsvlieg, totdat ze in 1995 met het album The Bends en de bijbehorende singles meer succes boekten. Het nummer vertoont op muzikaal gebied enige gelijkenis met The air that I breathe van The Hollies, een nummer geschreven door Albert Hammond en Mike Hazlewood. Radiohead kreeg daarom een proces aangespannen vanwege plagiaat. Radiohead werd veroordeeld en sindsdien worden Hammond en Hazlewood als medeschrijvers aan het nummer genoemd. Op hun beurt klaagde Radiohead Lana Del Rey aan omdat zij het akkoorden schema en de melodie van Creep grotendeels zou hebben gekopieerd en verwerkt in haar track Get Free uit 2017. https://nl.wikipedia.org/wiki/Creep_(Radiohead)

"Creep" remains Radiohead's most successful single. The members of Radiohead grew weary of the song, feeling it set narrow expectations of their music, and did not perform it for several years.... According to Yorke, "Creep" tells the tale of an inebriated man who tries to get the attention of a woman to whom he is attracted by following her around. In the end, he lacks the self-confidence to face her and feels he subconsciously is her. When asked about "Creep" in 1993, Yorke said: "I have a real problem being a man in the '90s... Any man with any sensitivity or conscience toward the opposite sex would have a problem. To actually assert yourself in a masculine way without looking like you're in a hard-rock band is a very difficult thing to do... It comes back to the music we write, which is not effeminate, but it's not brutal in its arrogance. It is one of the things I'm always trying: To assert a sexual persona and on the other hand trying desperately to negate it."[15] Jonny Greenwood said the song was in fact a happy song about "recognizing what you are".[5] According to Guardian critic Alexis Petridis, "Creep" has an "almost complete lack of resemblance to the music [Radiohead] went on to make".[16] https://en.wikipedia.org/wiki/Creep_(Radiohead_song)

Op hobbybrouwen kwam ik de term hopcreep tegen.

Met hop creep wordt het verschijnsel bedoeld van extra vergisting onder invloed van koudhoppen. In 2018 heeft Shellhammer een artikel gepubliceerd in het Journal of Agricultural and Food Chemistry over een onderzoek naar hop creep.  https://www.twortwat.nl/t-n/koudhoppen

It's a brewer's nightmare. You've dreamed and designed, you've planned, prepared and processed. Your beer is almost ready. After the fermentation is complete you add pressed hop cones, dry hopping for that extra aroma. Leaving the beer unfiltered to preserve the hazy look and feel, you bottle it. Finally, you can relax and enjoy the feeling of a job well done. Then it all goes wrong. The hops are added and hop creep begins. This is almost undetectable as the fermentation process can even begin inside the bottle. Hop creep is very difficult to detect and may not be discovered until the beer is consumed. It increases Diacetyl, alcohol, and CO2 levels as well as decreasing pH and gravity. Excess diacetyl, above the flavor threshold, leads to unpleasant buttery flavors, and suddenly your dream beer tastes like movie popcorn. https://www.dupontnutritionandbiosciences.com/brewing/articles/dont-worry-be-hoppy.html

What is Hop Creep At its core, hop creep is continued fermentation in the bottle or keg after the finished beer has been packaged for distribution. Symptoms include overcarbonation of bottles and kegs, over-attenuation of packaged beer, and diacetyl off flavors. It can occur in any unpasteurized or unfiltered packaged beer. Warm storage of the packaged beer can make the situation worse. The root cause of hop creep is high levels of dry hopping. Hops actually contain trace amounts of both alpha and beta amylase as well as limit dextrinase enzymes. After dry hopping these enzymes can continue to convert a small amount of starch into sugars even at room temperature. If yeast is still present the sugars will ferment, lowering the final gravity of the beer and also creating carbonation. The net effect can be as much as a 1-2 Plato drop in final gravity over a period of 40 days, which leads to a 5% increase in carbonation levels and 1.3% increase in alcohol (Kirkpatrick and Shellhammer). There tests were done at 20 C, and higher storage temperatures can result in even more attenuation. This means the bottles and kegs will be overcarbonated, and the increased attenuation can also affect the malt-hop balance and body of the finished beer – big problems for commercial breweries. In addition the fermentation will raise the diacetyl levels of the beer, and there will likely not be enough yeast to clean that diacetyl up resulting in a buttery off flavor in the finished beer. (http://beersmith.com/blog/2019/03/31/dry-hop-creep-over-carbonation-and-diacetyl-in-beer/)

Hop blijkt enzymen te bevatten die onvergistbare lange-keten-suikers kunnen afbreken tot eenvoudige, snelle suikers. Dit is vergelijkbaar met wat de enzymen in gerst tijdens het maischen doen. Deze enzymactiviteit blijft zonder gevolgen als er geen gist aanwezig is (suiker is suiker), maar als er gist aanwezig is, worden de net geproduceerde suikers omgezet in ethanol en CO2. Hop creep doet zich alleen voor bij koudhoppen. Immers, als hop wordt toegevoegd aan kokende of bijna kokende wort, zal de hoge temperatuur de enzymen in de hop denatureren (lees: uitschakelen). Hop creep kan een aanzienlijke impact hebben op bier, bijvoorbeeld op troebele NEIPA’s die dikwijls nog wat gist bevatten en die gekoudhopt zijn met grote hoeveelheden hop. Als het bier al gebotteld is, kan de extra CO2 zorgen voor zoveel druk dat flesjes exploderen. Het alcoholpercentage gaat omhoog. Bij het onderzoek met het Coors Banquet bier was het met 1,3% toegenomen. Er wordt extra diacetyl geproduceerd. Bij het onderzoek van Shellhammer ging het diacetylniveau omhoog van 25 ppb naar 200 ppb als gevolg van de extra vergisting door het koudhoppen. Hoe meer onvergiste suikers een bier bevat, des problematischer wordt de hop creep. Het zal dus eerder voorkomen dat een DIPA (Double IPA) ontploft dan een Brut IPA. Wie meer wil weten over ontploffende bierflesjes kan googelen op ‘exploding beer cans’ of het artikel Good Beer Hunting lezen van Bryan Roth. https://www.twortwat.nl/t-n/koudhoppen

Dat van die hopbommen van ontploffende flesjes kan ik me nog vaag herinneren, dat was een paar jaar terug nieuws.

Since this spring, as warmer weather has led to an annual transition of beverages that best pair with high temperatures and sweeter tastes, beers made with copious amount of berries or tropical fruit have caught the attention of drinkers and industry pros. The issue is the threat of refermentation that takes place after packaging due to sugars from fruit and/or sediment added late in the brewing process. A most recent example came from That’s What Happens When You Let Dad Outta the House, a collaboration between Evil Twin and Hoof Hearted Brewing that produced a sour IPA made with pineapple, guanabana, vanilla, and milk sugar. Not long after its release, a Reddit thread warning drinkers about cans exploding quickly accumulated 266 comments. There was a mixture of consumers decrying the threat of lost beer and potential injury, as well as others placing the burden of safety on buyers who aren’t educated. It was either the breweries’ fault for making the beer in the first place, or a customer’s fault for not knowing how to safely handle such a beer that states on its label “CONTAINS FRUIT. KEEP COLD AT ALL TIMES.” There were also multiple versions of posters sharing accounts of the problem. One said a few cases "exploded immediately upon being set down." Another said a store lost 19 cans, adding that "I felt like a bomb tech moving the rest of them to the sink." https://www.goodbeerhunting.com/sightlines/2018/8/22/exploding-cans

n August 2018, its brewers acknowledged some of its fruited, kettle-soured beer cans might explode if not refrigerated immediately after purchase, because yeast present in the cans could continue to ferment thanks to the the hummingbird-nectar levels of sugar added post-fermentation. Can conditioning isn’t new, but it is a delicate process that takes nuanced attention to allow a beer to finish gracefully—let alone safely. 450 North, however, opted to add levels of fruit that could have been a can’s kryptonite. https://www.goodbeerhunting.com/sightlines/2019/12/30/first-it-was-exploding-cans-now-450-north-shrugs-off-miscalculated-abvs

There is evidence that hops have amylolytic enzymes in or on them that biochemically modify beer during dry-hopping, leading to degradation of long-chain, unfermentable dextrins into fermentable sugars. This increase in fermentable sugars can, in the presence of yeast, give rise to a slow secondary fermentation, which is referred to as ‘hop creep.’ Hop creep requires three conditions for it to appear: (1) some amount of unfermentable real extract in the wort or beer prior to dry-hopping; (2) live yeast in suspension; and (3) the addition of hops to fermenting or fermented beer. The main consequences of hop creep result in beer being out of specification in terms of alcohol, diacetyl and CO2 (Table 1). It is particularly concerning when it occurs post-packaging because of the consumer safety risk related to package over-pressurization. Methods for controlling hop creep, to either accentuate or reduce it, involve manipulating wort composition, yeast strain selection and suspended cell concentration during dry-hopping, and dry-hop form, timing, contact time and temperature. (https://www.brewersassociation.org/educational-publications/hop-creep-technical-brief/)

Hop creep is een lastig probleem. Om hier geen last van te hebben kun je het koudhoppen achterwege laten. https://www.hobbybrouwen.nl/forum/index.php?topic=40484.0 

Dry-hopping is a common technique used in the brewing process. It is a post fermentation hop addition that adds an intense hop aroma character to beer. With this hop addition, brewers have experienced over attenuation in their beers. This over attenuation is more commonly referred to as “hop creep” in the brewing community. Hop creep is essentially the refermentation experienced after dry-hopping a fully fermented beer. The refermentation can be easily observed by monitoring the increase in alcohol and CO2­ with a subsequent decrease in specific gravity. Brewers that are dry-hopping should be aware of and monitor the over attenuation experienced with this hop addition. Over attenuation causes issues for brewers that are looking to meet brand specifications such as flavor profile, specific gravity and alcohol content. In addition, refermentation has been known to cause over pressurization in packaged bottled beers due to the increase in CO2, causing bottle caps to explode, which is a safety concern for distributors, retailers and customers. https://www.sea-brew.com/post/hop-creep-the-over-attenuation-experienced-when-dry-hopping

The current research available on dry-hopping and over attenuation of beer seems to conclude that hops contain starch degrading enzymes (Diastase: mixture of amylase enzymes) that break down unfermentable carbohydrates into fermentable sugars. These fermentable sugars can then be metabolized by yeast and produce ethanol and CO2. Unfermentable carbohydrates in conjunction with hop starch degrading enzymes and active yeast causes over attenuation.  A summary of this research is provided along with suggested ways to help control hop creep is discussed. The Early Years: The first published research on the effects of dry-hopping producing a refermentation is by Brown and Morris in 1893 (1). They stated that the refermentation could be caused by several sources like wild yeast, fermentable carbohydrates in hops and the presence of diastase in hops. They ruled out the wild yeast because refermentation started before the development of wild yeast from hops. They also stated that hops do not contain enough fermentable carbohydrates to account for the amount of refermentation observed. It was concluded that the diastase enzymes in hops is the cause of refermentation. To test for enzyme activity, aqueous hop solutions were made with a tannin binding agent called hide-filings, and when these solutions were added into a soluble starch solution, the starch was converted into maltose. The next published research comes about 50 years later. In 1941 Janicki, Kotasthane, Parker and Walker wrote an article titled “The Diastatic Activity of Hops Together With a Note on Maltase in Hops” (2). They continued with the previous research by making aqueous hop solutions and removing tannins with a binding agent and concluded that peptone was a better binding agent than hide-filings (1). Their data showed that, without removal of the tannins, there was no diastase activity. They determined the diastase was not extracted in the solution in the presence of tannins. .... After 1941 until 2015 there does not appear to be any published research on the over attenuation of dry-hopped beers. This is probably due to the craft brewery boom we are currently experiencing with the increase in dry-hopped beers in the market place. It appears that the refermentation from dry-hopped beers was all but forgotten.

The Rediscovery of Refermentations Caused by Dry-Hopping:

Dry-hopped beers are a style of beer that nearly all craft breweries produce and, with this production, most have experienced refermentation after dry-hopping. They may not have known what the cause was, but they reported:

decreases in gravity

increases in alcohol

increases in diacetyl (buttery off flavor in beer)

exploding bottles in the warehouse in their dry-hopped brands.

All of this is evidence of over attenuation caused by dry-hopping in the presence of active yeast and unfermentable carbohydrates, which is now named “hop creep”. Although presentations at industry conferences in 2015 (3) would discuss this phenomenon, no new research would be published until 2018. In June 2018 Kirkendall, Mitchell and Chadwick published an article titled “The Freshening Power of Centennial Hops” (4). Their research was completely focused around dry-hop trials and monitored the over attenuation of the trials by measuring specific gravity and alcohol.https://www.sea-brew.com/post/hop-creep-the-over-attenuation-experienced-when-dry-hopping

Hop creep, or the over attenuation observed with beers that are dry-hopped, is not a new discovery and has been documented since 1893. The research behind this phenomenon has been reignited with the amount of dry-hopped beers that are now being produced. The cause of this over attenuation is from hop starch degrading enzymes breaking down unfermentable carbohydrates into fermentable carbohydrates in the presence of active yeast. Hop creep can easily be monitored by measuring alcohol and specific gravity. According to the early research, enzyme activity is highest within the seeds of hop plants, but is definitely in the hop cone as well. The hop enzyme activity of individual hop cultivars does not appear to be distinguishable at this time. Factors that affect the enzyme activity of a hop is not only genetic, but influenced by agronomics, maturity, postharvest handling and processing. One factor that seems to be agreed upon in the research is that the tannins in hops affect the enzyme activity and identifying these specific inhibitory compounds will probably be the focus of future research. Brewers who have dry-hopped brands of beer must be aware of and monitor the over attenuation that happens with dry-hopping. It is imperative for consumer safety (as it can cause bottles to explode from the pressurization of CO2 increased in closed systems), the regulation of stated alcohol content on labels, as well as maintaining flavor/aroma specifications for a beer brand. Hop creep can be controlled by use of contact time, temperature and wort gravity. https://www.sea-brew.com/post/hop-creep-the-over-attenuation-experienced-when-dry-hopping

Op https://www.sea-brew.com/post/hop-creep-the-over-attenuation-experienced-when-dry-hopping is een hele lijst met bronnen te vinden trouwens.

Meer hop toevoegen bij het koudhoppen leidt niet simpelweg tot sterkere aroma's, het verandert ook de aard van het aroma in het uiteindelijke bier. Hoeveelheden van meer dan 8 gram hop per liter geven aroma’s die meer kruiden/thee van aard zijn dan citrus. Onderzoek wijst uit dat een hoeveelheid van 4 tot 8 gram hop per liter bij het koudhoppen leidt tot een meer evenwichtig hoparoma. Levert koudhoppen wel bitterheid op? Tot voor kort dachten brouwers en onderzoekers dat de bitterheid uit hop bijna geheel te danken was aan geïsomeriseerde alfa-zuren tijdens het koken van het wort. De alfa-zuren in hop zijn van zichzelf niet bitter en lossen heel moeilijk in water op, maar door het koken worden ze geïsomeriseerd. Bij isomeriseren verandert het molecuul van vorm doordat de atomen herschikt worden. Door deze verandering neemt de bitterheid en de oplosbaarheid toe. Koudhoppen vindt plaats bij vergistingstemperaturen en dat is te koud om voor isomerisatie te zorgen. Vandaar dat tot nu toe werd gedacht dat bij koudhoppen geen bitterheid afgegeven kon worden. Tegenwoordig worden veel IPA’s met een sterk fruitaroma gebrouwen en een lage bitterheid. Brouwers voegen steeds minder (en soms zelfs bijna helemaal geen) hop toe tijdens de kooktijd en juist veel meer bij het koudhoppen. Als gevolg daarvan zijn niet alleen brouwers maar ook onderzoekers als Shellhammer kritisch gaan kijken naar eerdere aannames. Uit onderzoek van Shellhammer blijkt dat humulinonen en polyfenolen veel bitterheid kunnen afgeven in bier dat met veel koudhop gebrouwen is. In tegenstelling tot de geïsomeriseerde alfa-zuren, hoeven deze componenten niet gekookt te worden om bitter te worden. Sterker nog, omdat humulinonen gevormd worden wanneer niet-geïsomeriseerde alfa-zuren oxideren, is dit effect nog heviger bij oude hop die gedeeltelijk geoxideerd is. Wat betekent dit in de praktijk? Dat de lage IBU’s van troebele, fruitachtige NEIPA’s weinig zeggen. Wie weinig bitterheid wil, moet brouwers zoeken die koudhoppen met zeer verse hop. https://www.twortwat.nl/t-n/koudhoppen

Hop Creep was first studied as long ago as 1893 by the pioneering brewing scientist Horace T. Brown and his assistant G. Harris Morris.[1] They called it "the freshening effect of hops" , and proposed three possible causes of refermentation; 1. hops could contain fermentable sugars, 2. hops could introduce wild yeast into the brew, or 3. hops contain endogenous enzymes which trigger the fermentation process anew. They found their third hypothesis was correct and that hop creep was caused by enzymes in hops.

Hops contain many types of enzymes, and the levels vary according to hop variety and season. Alpha amylases help break down simpler sugars, limit dextrinase debranches unfermentable starches, and beta amylases, glucoamylases and maltase enzymes break down starch into fermentable sugars. It is this last group of starch degrading enzymes that cause dry hop creep.

Usually enzymes from hops are deactivated by heat during boiling and all fermentation is stopped. Hop creep only occurs when amylolytic enzymes from hops are introduced during dry hopping. This can potentially lead to refermentation if there is adequate starch material for the diastases to act on, and yeast is present. Trendy, hazy, unfiltered beers such as New England style IPAs provide plenty of fermentable material for the hop enzymes to work upon. Hop creep has returned.

 https://www.dupontnutritionandbiosciences.com/brewing/articles/dont-worry-be-hoppy.html

While it is possible to avoid hop creep by autoclaving hops at a high temperature and pressure to deactivate the enzymes, this isn't ideal as it significantly changes the hop flavor.

Luckily there is a better way. Nutrition & Biosciences ALPHALASE® Advance 4000 is a flexible enzyme that works across a wide range of conditions to control diacetyl levels. ALPHALASE® Advance 4000 limits the formation of diacetyl by directly breaking down the diacetyl precursor 2-acetolactate into flavorless acetoin. When added at the start of the fermentation process, ALPHALASE® Advance 4000 not only prevents hop creep, but also reduces diacetyl formation during the main fermentation process, giving you a faster and more efficient fermentation and maturation period. https://www.dupontnutritionandbiosciences.com/brewing/articles/dont-worry-be-hoppy.html

Dus hop in je bier kan ook nog vergisting te veroorzaken. Met boterige popcornsmaak tot gevolg? ik heb dat nog nooit geproefd.