Pre-Boil Hopping

Breaking traditions has become a theme that both craft brewers and homebrewers alike strive for in their beers. One only needs to look at the US Brewers Association’s definition of a craft brewer to see this: “The hallmark of craft beer and craft brewers is innovation. Craft brewers interpret historic styles with unique twists and develop new styles that have no precedent.” I take that statement with a grain of salt since in my opinion many of these new and “innovative” techniques that brewers are using have roots in the past. Our forefathers had several millennia working on techniques and recipe development for the production of malted beverages. So to say something has no precedent, well I’ll argue that more than likely, there is a precedent somewhere buried in the past.

During the dark ages of beer brewing post-World War II, when pale lagers came to dominate the global market, regional and sub-regional beer styles and generations of brewing knowledge were slowly and systematically snuffed out. Part of the renaissance of beer brewing over the past four decades has been in re-discovering these old practices. Germans, in particular, were relegated by law to brewing with a very limited range of ingredients to include in their beers. What evolved was a very technique-oriented brewing style where timing and ingenuity was required.

Two of those older techniques that fell by the wayside, first wort and mash hopping, have found new promise in modern brewing. First wort hopping is a hopping technique that was actually a very prominent form of hopping even one century ago in several brewing regions. Mash hopping is a less prominent technique that may have found a new place in the heart of our current brewing renaissance.

First Wort Hopping

As far as adjusting a brew day technique, it really doesn’t get any easier than trying first wort hopping (FWH). While there is still some ambiguity that surrounds its overall affect on the finished beer, most brewers will either use it as a substitute for their bittering hop charge or their mid-boil hop charge. So why the ambiguity? Well it has been shown in tastings that first wort hopping can increase the perceived aroma of a beer when substituted for a traditional late hop addition to the kettle. Yet when a group of scientists tested the hop aroma components of FWH beers, they found that the aroma compounds were actually considerably lower in first wort hopped beers versus the same beer with that late hop addition. So let’s delve into what first wort hopping is and indicate when you possibly should and should not use this technique.

First wort hopping if you are not familiar with it, is very simple. Add a portion or all of your late boil hop charge or bittering hops before the wort comes to a boil. It does not matter whether you are an all-grain or extract brewer. Generally as an all-grain brewer I do this about 3-5 minutes into the sparging process of the grain bed. When I’m using extracts, I generally wait until the wort has gotten up to about 180 °F (82 °C) before tossing the FWH into the kettle.

So what does FWH do for your beer? What repeated studies have shown from blind triangle taste tests is that it creates a softer, more rounded bitterness than adding your bittering hops to a rolling boil. There are two studies in particular that document this effect. The first is a fairly comprehensive study put out back in 1995 by a German group of researchers Preis, Nuremberg, Mitter & Steiner titled “The re-discovery of first wort hopping,” published by Brauwelt International. The second study was performed by US homebrew guru Denny Conn, whose results roughly affirmed that of the German researchers and presented his findings at the 2008 AHA Conference.

The German researchers utilized two breweries to test first wort hopping versus a late hop addition. The taste tests from both breweries confirmed that there is a distinct difference between a beer with first wort hopped charge and bittering charge and beers brewed with a traditional bittering charge and late hop charge. Among those on the panel, 21 out of 23 tasters were able to recognize the taste discrepancy in a Pilsner. Of those 21 tasters who distinguished some difference between the two beers, 19 of them preferred the first wort hopped beer. That is enough to raise my eyebrows. Denny Conn’s study, which was performed with two groups of BJCP judges and professional brewers, tested FWH beers versus a traditional bittering charge. What they found in a blind triangle test was that seven of the eighteen tasters were able to distinguish the first wort hopped beer; still significant but not quite as striking as the German study. The general consensus among those that could distinguish among the two beer types was that the first wort hopped beer offered a smoother bittering profile than the reference beer.

The other aspect that the two studies confirmed is that first wort hopping will increase your bittering units without increasing the perceived bitterness. The IBUs of a beer that has been first wort hopped achieve on average ~10% more hop utilization when analyzed against the same beer with a standard 60 minute hop addition. The Germans found in the first Pilsner with FWH 39.6 IBUs, compared to 37.9 IBUs for the reference beer. The second Pilsner was found to have 32.8 IBUs and the reference beer had 27.2 IBUs. Denny Conn’s beers when analyzed had 24.8 IBUs for the FWH beer and 21.8 IBUs for the reference beer. The German study also showed that the iso-alpha acid concentration was quite a bit higher for the FWH beers. But again, taste tests revealed that the actual perception of the bitterness levels are slightly lower for the FWH beers. In other words, they had less bite.

So when is it advisable to utilize the FWH technique? Pretty much any beer you plan a bittering addition to mid-boil hop addition could be FWH’d. I do tend to use this technique when brewing beers that are more malt forward, or with well rounded styles such as continental lagers, roasted grain- focused beers, wheat beers and Scottish ales to name a few. Sometimes I will skip FWH and stick to a more traditional hopping schedule when I’m looking for more bite in the beer, such as with American IPAs, double IPAs, robust porters or imperial stouts. I’ve used FWH with all those styles as well with great results. I’ve also split my bittering hops so that half go in at first wort, and the second half go in with 60 minutes left in the boil. Another counter-indication for me is if I’m planning on boiling more than 75 minutes. I don’t like to have my hops in contact with boiling wort for more than ~75 minutes for fear of polyphenols leaching into the wort from the hops. With that said, it has been reported that Pilsner-Urquell first wort hops their classic Pilsner and boils for 2 hours. Hard to argue with a classic like a Pilsner-Urquell.

So why does first wort hopping work? That is still not fully understood according to my research. All I can do is offer some theories as to why it provides a smoother bitterness. There are three primary alpha acids found in hops: humulone, cohumulone and adhumulone. Relatively, they are not that bitter, but when heated above about 175 °F (80 °C) they will isomerize (re-arrangement of the molecule) into iso-alpha form: iso-humulone, iso-cohumulone and iso-adhumulone respectively. At this point they are several times more bitter than their non-isomerized cousin. In the isomerization process each alpha acid is further divided into the cis and trans states. This is akin to left-handed vs. right-handed states; they are mirror images of each other, just flipped. Each of those forms acts slightly differently as well. Another factor that could play a key role here are hop glycosides which have been the focus of many discussions surrounding misunderstood components of hops. So why am I explaining all this? Well just to show that there is a lot going on in the bittering process. Add in beta acids plus oxidative reactions that are occurring on the various oil components and you can see that complex nature at a molecular level in your wort when hops are added.

The long and short of my hypothesis is that the isomerization reaction proceeds along slightly differently when hops are added off boil, 175–210 °F (80–99 °C). Maybe you get more cis-iso acids or vice versa. I don’t have any empirical evidence for this theory, just anecdotal evidence when I’ve compared exclusively FWH beers to exclusively whirlpool hopped beers. We talk in similar terms when describing the bitterness of the beers hopped at off-boil temperatures, whether it is pre- or post-boil hopped. I have brewed both techniques on a cream ale, exclusively pre-boil FWH and exclusively post-boil whirlpool hopped beers and find the bittering qualities to match up fairly well. The whirlpool hopped beer had abundantly more hop nose and flavor, but the FWH beer had some hop aroma when compared to a standard American lager. My results are right in line with the German taste panel’s findings, that FWH beers had slightly more hop aroma. The mystery deepens since this contradicts the German team’s research when they performed gas chromatography on the resulting beers. What they found was that the FWH beers contained significantly less hop aroma compounds compared to the reference beers. The ultimate empirical answer to the mystery of why it works will have to await more scientific research. For now, I have to use my anecdotal evidence.

Mash Hopping

Mash hopping is a much different beast than FWHing. First off, it is for partial mash and all-grain brewers only. Second, iso-alpha acid conversion does not take place at an appreciable level at mash temperatures, so alpha acids do not undergo the isomerization reaction. The oils that are extracted from the hops will most all be driven off during the boil, so why would anyone give mash hopping a second look? Well there may actually be a reason to take a look down this worm hole for a very specific purpose.

Mash hopping is simply adding a hop charge to the mash. I have always used whole leaf hops when mash hopping since it will aid in grain bed filtration in a manner somewhat akin to adding rice hulls. Mix the hops in at the beginning of the mash and do not change anything else about the mash.

So if the alpha acids are not going to convert and say 98% of them are left in the mash tun and the oils will be driven off in the boil, why use it? Well what if you’re planning on boiling the mash and what if the only time you’re going to boil on that given brew day is during the mash? Two fairly well documented mashing techniques may come to mind; decoction and turbid mashing when answering the first question. The second question is found again by looking at what was done in the past.

Traditionally brewers have always boiled their wort after lautering for a minimum of 60 minutes. If Pilsner malt is used, that boil time is generally increased to at least 90 minutes to offset the increased levels of S-methyl methionine (SMM) (the dimethyl sulfide/DMS pre-cursor molecule) found in this lightly kilned base malt. But in this brewing renaissance everything can be questioned and the requirement of boiling is one of them. A scan through the history books found brewers in the past who have tried this no-boil technique.

So let me explain the no-boil technique, then I can get into why mash hopping is perfect for this technique. I first learned about no-boil beers from reading Michael Tonsmeire’s brewing blog “The Mad Fermentationist.” In a post from 2008 he talks about reading Eric Warner’s book titled German Wheat Beer. Mr Warner explains that traditionally a Berliner Weisse beer had the wort go directly from the lauter tun to the coolship, bypassing the kettle and boil process entirely. Tonsmeire took this concept and decided to apply it to his next Berliner weisse. There is one glaring problem with this, however: Berliner weisse uses a lot of Pilsner malt. Wouldn’t DMS be a huge problem with the finished beer? Well what Mr. Tonsmeire and the ensuing wave of no-boil experimenters found was that DMS doesn’t seem to be a major problem with these beers. Does the bacteria possibly mask the low levels of DMS that would be found in a no-boil beer or could the lack of a boil somehow prevents DMS or could it be that the DMS is oxidized by the acids produced by the bacteria or simply scrubbed out during the fermentation process? Once again, I could not find anything but anecdotal evidence that supports that no-boil beers will result in beers without the cooked cabbage like aromas that are associated with DMS. Needless to say, more intensive studies into this matter could result in some conclusive evidence as to why this may be the case by measuring DMS levels in the finished wort of a no-boil beer and the DMS levels post-fermentation.

Now to turn this back into mash hopping, what has evolved is a no-boil beer where a brewer can get their very small quantities of iso-alpha acids desired for a beer like a Berliner weisse from a mash that has been hopped, then isomerization occurs during the ensuing decoction process — depending on how much mash you are looking to pull for the decoction. So for argument’s sake you have added hops in the entire mash and decide to pull half of the mash for decoction, then for calculation purposes simply consider that half of the hops are being boiled for the duration of the decoction boiling. Or you can save some money on hops by simply adding the hops directly to the pulled decoction. With a beer like a no-boil Berliner weisse whole leaf hops will now perform two functions, assist in grain bed filtration and provide the low levels of iso-alpha acids. Where else could you use this technique? Lambic-styled beers, gose and other sour beers seem like a good fit for mash hopping if boiling is not truly required in sour beers.

First Wort Hop Recipes

Weihen-not Hefe

(5 gallons/19 L, all-grain) OG = 1.051 FG = 1.011IBU = 13 SRM = 5 ABV = 5.5%

While I was going for a Weihenstephaner Hefe Weissbier clone with this beer, I found that using just wheat and Pilsner malt lacked the malt depth when compared to the original, even when I double decocted the mash. I added some dark Munich malt and melanoidin malt to try to coax a layer of complexity which the original German hefeweizen displays. I also adjusted the hops from a low alpha acid variety, Hallertau Mittelfrüh, to the higher alpha German Magnum to minimize extraction of polyphenols considering the longer contact time with the wort.

Ingredients

  • 5.5 lbs. (2.5 kg) German wheat malt
  • 4 lbs. (1.8 kg) continental Pilsner malt
  • 12 oz. (0.34 kg) dark Munich malt (9 °L)
  • 4 oz. (0.11 kg) melanoidin malt
  • Rice hulls (optional)
  • 3 AAU Magnum hops (FWH) (0.25 oz./7 g at 14% alpha acid)
  • Wyeast 3068 (Weihenstephaner Weizen) or
    White Labs WLP300 (Hefeweizen Ale) or
    Lallemand Munich Wheat yeast
  • Priming sugar (if bottling)

Step by Step

This is a step infusion mash. Dough-in the crushed grains to achieve a mash temperature of 112 °F (44 °C) for ferulic acid development. Let rest for 20 minutes then raise the mash temperature to 152 °F (67 °C) for saccharification conversion. Rest at this temperature for 45 minutes then begin lautering. If you are using rice hulls, add them prior to starting your lauter. Once you begin your run-off into your kettle add the hops. If you are fly sparging, be wary of the specific gravity — or more specifically the pH of your run-off. If your specific gravity drops below 1.010, shut down the sparge and top off the kettle. Collect 6 gallons (23 L) of wort and boil for 60 minutes. After knockout, begin a whirlpool and let the wort spin down for 10 minutes.

Chill the wort to 65 °F (18 °C), pitch an appropriate yeast starter (~1 qt./1 L) and aerate the wort thoroughly. Ferment at 68 °F (20 °C). Carbonate the beer to 3–3.5 volumes CO2. For carbonation guidelines, visit http://byo.com/resources/carbonation

Weihen-not Hefe

(5 gallons/19 L, extract only) OG = 1.051 FG = 1.011 IBU = 13 SRM = 5 ABV = 5.5%

Ingredients

  • 6.6 lbs. (3 kg) wheat liquid malt extract
  • 0.5 lbs. (0.23 kg) Munich liquid malt extract
  • 3 AAU Magnum hops (FWH) (0.25 oz./7 g at 14% alpha acid)
  • Wyeast 3068 (Weihenstephaner Weizen) or
    White Labs WLP300 (Hefeweizen Ale) or
    Lallemand Munich Wheat yeast
  • Priming sugar (if bottling)

Step by Step

Add 5.5 gallons (21 L) water plus malt extract to your kettle. When temperature of the kettle reaches about 180 °F (82 °C), add the hops. Now follow the boil, fermentation and packaging instructions in the all-grain recipe.

Otto’s Jacket Pale Ale

(5 gallons/19 L, all-grain) OG = 1.058 FG = 1.013 IBU = 57 SRM = 6 ABV = 6%

For my first brew with MosaicTM, I decided to pair it with Chinook and Apollo. The resulting beer was pretty fantastic, something Lisa Simpson might liken to Otto’s Jacket (credit to Jack Horzempa for the name). This one clocks in at 57 IBUs, but tastes more like 45 IBUs.

Ingredients

  • 11.25 lbs. (5.1 kg) North American 2-row pale malt
  • 8 oz. (0.23 kg) CaraVienne® malt (24 °L)
  • 6 oz. (0.17 kg) honey malt
  • 4.6 AAU Apollo hops (FWH) (0.25 oz./7 g at 18.5% alpha acid)
  • 9.3 AAU Apollo hops (5 min.) (0.5 oz./14 g at 18.5% alpha acid)
  • 11 AAU MosaicTM hops (0 min.) (1 oz./28 g at 11% alpha acid)
  • 7 AAU Chinook hops (0 min.) (0.5 oz./14 g at 14% alpha acid)
  • 1.5 oz. (43 g) MosaicTM hops (dry hop)
  • 0.5 oz. (14 g) Chinook hops (dry hop)
  • 0.5 oz. (14 g) Apollo hops (dry hop)
  • Wyeast 1272 (American Ale II) or
    White Labs WLP051 (California V) or
    Lallemand Nottingham yeast
  • Priming sugar (if bottling)

Step by Step

This is a single infusion mash. Heat 4.5 gallons (17 L) strike water to 165 °F (74 °C) to stabilize the mash temperature at 154 °F (68 °C). Rest at this temperature for 45 minutes then begin lautering. Once you begin your run-off into your kettle, add the first wort hops. Collect 6 gallons (23 L) of wort and boil 60 minutes. After knockout, begin a whirlpool and let the wort spin for 20 minutes.

Chill wort to 63 °F (17 °C), pitch an appropriate yeast starter (~1 qt./1 L) and aerate the wort thoroughly. Ferment at 65 °F (18 °C). After primary fermentation subsides, add dry hops for 10 days before packaging. Carbonate the beer to 2.4 volumes CO2.

Otto’s Jacket Pale Ale

(5 gallons/19 L, extract with grains) OG = 1.058 FG = 1.013 IBU = 57 SRM = 6 ABV = 6%

Ingredients

  • 6.6 lbs. (3 kg) pale liquid malt extract
  • 12 oz. (0.34 kg) light dried malt extract
  • 12 oz. (0.34 kg) CaraVienne® malt (24 °L)
  • 4.6 AAU Apollo hops (FWH) (0.25 oz./7 g at 18.5% alpha acid)
  • 9.3 AAU Apollo hops (5 min.) (0.5 oz./14 g at 18.5% alpha acid)
  • 11 AAU MosaicTM hops (0 min.) (1 oz./28 g at 11% alpha acid)
  • 7 AAU Chinook hops (0 min.) (0.5 oz./14 g at 14% alpha acid)
  • 1.5 oz. (43 g) MosaicTM hops (dry hop)
  • 0.5 oz. (14 g) Chinook hops (dry hop)
  • 0.5 oz. (14 g) Apollo hops (dry hop)
  • Wyeast 1272 (American Ale II) or
    White Labs WLP051 (California V) or
    Lallemand Nottingham yeast
  • Priming sugar (if bottling)

Step by Step

Steep your crushed grains in 2 qts. (1.9 L) water at 160 °F (71 °C) for 20 minutes. Wash the grain bag with hot water. Top off kettle to 6 gallons and stir in the extracts. When the wort hits about 180 °F (82 °C), add the hops. Now follow the fermentation and packaging instructions in the all-grain recipe.

Mash Hop Recipe

Nicht-boil Berliner

(5 gallons/19 L, all-grain) OG = 1.032 FG = 1.005 IBU = 5 SRM = 3 ABV = 3.5%

This recipe is inspired by Michael Tonsmeire’s modern take on the no-boil method. Make sure to keep your IBUs extremely low (<5 IBUs) to insure that the Lactobacillus will not be inhibited.

Ingredients

  • 4 lbs. (1.8 kg) Pilsner malt
  • 2.5 lbs. (1.13 kg) wheat malt
  • Rice hulls (optional)
  • 4.5 AAU Hallertau Mittelfrüh hops (mash hop) (1 oz./28 g at 4.5% alpha acid)
  • Wyeast 5335 (Lactobacillus) or
    White Labs WLP677 (Lactobacillus Bacteria) or
    Wyeast 1007 (German Ale) or
    White Labs WLP036 (Dusseldorf Alt) yeast
  • Priming sugar (if bottling)

Step by Step

One week prior to brew day, make a 1 qt. (1 L) starter with the Lactobacillus. Do not place the starter on a stir plate but try to get the starter in a spot near your house boiler where temperatures would be above room temperature or a similar location with elevated temperatures. This should give the Lacto a jump start in order to get a nicely soured beer. If you are able to find one of the Berliner weisse yeast blends, you can alternatively pick up Wyeast 3191 (Berliner Weisse Blend) or White Labs WLP630 (Berliner Weisse Blend) or East Coast Yeast ECY06 (Berliner Blend) yeast which would blend one or more strains of Lactobacillus bacteria as well as a German ale yeast plus sometimes a Brettanomyces yeast as well.

This is a decoction mash. Dough-in with 4 qts. (3.8 L) water, mix the crushed grains and hops to achieve a mash temperature of 95 °F (35 °C). Rest for 10 minutes then raise the grain bed to 135 °F (57 °C) with the addition of boiling water. Let rest for 10 minutes then pull (decoct) half the grains (thick mash with little wort) and boil the grains for 20 minutes stirring often to avoid scorching them. Return the decocted portion back to the main mash to help raise the temperature up to saccharification temperatures to 152 °F (67 °C) for saccharification conversion. Rest at this temperature for 45 minutes. At this point you can pull a second decoction, which would require you to cut down on your mash hop quantities to half an ounce (14 g) or you can simply raise your mash up to 170 °F (77 °C) by using a recirculating heat method or by infusing boiling water to the mash. If you are using rice hulls add them prior to starting your lauter. Rest for 15 minutes and begin lauter phase. Once you start running off, send the wort directly into the wort chiller or fermenter. If you are fly sparging, be wary of the specific gravity or more specifically the pH of your run-off. If the pH of your grain bed rises above 6, your brew is susceptible to tannin extraction. One solution is to acidify your sparge water to pH 6 with the addition of phosphoric or lactic acid.

Collect 5 gallons (19 L) of wort. If the wort is not chilled, place wort in a cool spot or fridge to get it down to about 110 °F (43 °C) and pitch the pure Lactobacillus. Make sure that you have raised the temperature of the Lacto starter up to about this temperature as well since you don’t want to shock the bacteria. After about 12 hours when the temperature of the wort has cooled to yeast fermentation temperature of 65 °F (18 °C), pitch the ale yeast and hold at this temperature for duration of primary fermentation. Do not aerate the wort.

After primary fermentation is complete, you can raise the temperature of the wort up to around 80 °F (27 °C) to let the souring process occur more rapidly. One to three months of aging would be a minimal recommended time period to properly sour this beer.

Carbonate the beer to three volumes of CO2. For carbonation guidelines, visit http://byo.com/resources/carbonation.

You can serve this beer with a raspberry syrup known as Himbeere (red) or a woodruff syrup know as Waldmeister (green). This is a light and refreshing brew best enjoyed on a hot summer afternoon.

from BYO

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