Article

Bring on the Warmth

When the cold winds blow, jack-o-lanterns are removed from porches, and pumpkin beers disappear from store shelves, we know winter is upon us. The coming of winter calls for warming up, from putting on a favorite sweater, chopping wood and lighting fires, to breaking out those big beers you’ve been saving. Don’t wait until it’s deep into winter to discover you are out; start brewing now to have an ample supply for those long, cold nights.

Many styles of beer can serve as a wintertime companion, but in this article, I’ll take a closer look at three high-ABV styles that can help shake off the frost: Barleywine, wheatwine, and imperial stout. The general tips I give for brewing big beers (which I arbitrarily define as beers 8% ABV and up) will work for all of these, as well as other high-gravity favorites. The areas of specific interest to me when brewing big beers, and I’ll discuss more in depth next, are recipe formulation, the brewing process, fermentation, and conditioning.

Recipe Formulation

There are a few things to keep in mind when creating a recipe for a strong beer. First is that big beers tend to have more body and flavor, and a higher finishing gravity than normal strength beers. I tend to use lower percentages of crystal-type malts in big beers than in low-gravity beers because the base malt itself provides richness. Munich-type malts are an alternative for providing added maltiness without as much residual sugar sweetness. Sugary adjuncts can be used for flavor and sometimes for boosting starting gravity, but excessive use of sugary and starchy adjuncts can result in a nutrient-poor wort that is not a good environment for subsequent fermentation. I sometimes add a pinch of a dark malt in the grist for color adjustment, but also to improve storage characteristics due to anti-oxidant properties.

I often think about using the no-sparge brewing technique, sometimes called brewing with first runnings. Rather than sparge the mash, simply run off the mash and use that as your starting volume of wort. Of course, you have to have enough liquid in the mash to reach your starting volume. I will use an infusion of near-boiling water to raise the mash temperature at mashout, which also increases my runoff volume.

The no-sparge technique has a lower mash efficiency than when you sparge, so you have to increase grist weight accordingly. I find that increasing the grist by about one-third is needed if you follow this technique. The idea is that you are sacrificing mash efficiency for better flavor from first runnings and a higher gravity of runoff. Of course, the mash can be sparged to create a smaller beer from the second runnings. 

Another consideration for brewing big beers is your mash volume. A larger grain bill will require a larger mash tun to brew your usual batch sizes. A 5-gallon (19-L) batch will often require a 10-gallon (38-L) mash tun.

The Brewing Process

Recall that bigger beers tend to have more body and a higher final gravity unless you take additional measures to counter this effect. One thing that you can do is mash at a lower temperature to increase attenuation. Mashing in the range of 144-149 °F (62–65 °C) favors beta-amylase activity, which is the enzyme that produces the highly-fermentable maltose sugar. If you are concerned about body, you can always add dextrin-rich malt such as Carapils®.

You also want to develop sufficient nutrients (free amino nitrogen, or FAN) to support a healthy fermentation. If you are using well-modified malts and avoiding excessive sugary and starchy adjuncts, this should happen naturally. However, if you want to be sure, keep your mash pH in the lower range (5.1 to 5.2), mash with a thicker water-to-grist ratio — 1.5 qts./lb. (3.1 L/kg) or less — to protect the enzymes, and mash for a longer period of time (up to 2 hours). Keep the mash well-stirred, but avoid heavy shearing forces (whipping the mash or pumping it fast). Conduct an iodine test to see if starches are fully degraded before proceeding to lauter. FAN can also be preserved by limiting the boil to 60 minutes, since longer boils can reduce FAN content.

Fermentation

Remember that wort is yeast food, and that you are trying to create a hospitable environment for fermentation. When brewing big beers, you are creating problems for yeast. The osmotic pressure of high sugar density stresses yeast cells, and the alcohol produced during fermentation is toxic to yeast. Selecting yeast strains that have higher alcohol tolerance gives you some increased margin of error, but you have more work to do. Higher gravity brewing increases esters and higher (fusel) alcohols in beer, so you don’t want to add even more stress to the fermentation that exacerbates that effect.

Using more yeast is important in higher gravity beers, especially lagers. Use more yeast packs, make starters with yeast nutrients, step up your starters, or reuse yeast from a previous batch. I sometimes will get a fresh pitch of yeast from a commercial brewery if making a big beer to ensure maximum viability. If reusing yeast from your own brewing, you might want to add yeast nutrients that contain zinc (such as Servomyces) to improve yeast health and performance. 

I will oxygenate the wort with pure oxygen before pitching the yeast to encourage yeast growth and a healthy start to fermentation. I run my oxygen through a sintered stone and let it go full blast for around a minute. When you do pitch the yeast, don’t pitch it into wort colder than the starter, which can shock the yeast. Keep the starter at the same temperature as the wort or slightly cooler.

I try to pitch on the cooler side of ale temperatures most times, around 64 °F (18 °C), and to keep the fermentation cool for the first three days. Then I allow the yeast to free rise in temperature during fermentation to help it finish and fully attenuate the beer. Rousing the beer gently during fermentation to keep the yeast in suspension also can help.

Conditioning

Big beers can take some time to condition, so plan ahead and leave sufficient time for this phase. The commercial beer Samichlaus was famously aged for a year before being released. Some big beers are vintage dated to encourage cellaring. I quite enjoy a well-aged big beer for the additional flavor complexity that can develop with time.

If you have the ability to drop the trub and spent yeast from fermentation, you may consider doing this prior to conditioning — it can help improve flavor stability, clarity, and foam, while avoiding the potential for developing some off-flavors. Racking your beer to a secondary vessel or dropping yeast from a cylindroconical fermenter can achieve this. Repitching with fresh yeast might help a beer that isn’t quite attenuated enough, but it also can help with maturing the beer. You don’t necessarily have to use the same yeast strain. I have used a more attenuative strain, and have also packaged with a lager strain to work better at cool temperatures.

Take special care to avoid introducing oxygen during packaging and seal your containers (bottles, kegs, or other storage units) well to avoid extra oxidation. Having live yeast in your packaged beer will result in a longer shelf life for your beer, and might help scavenge any remaining dissolved oxygen. Store your beer in stable cellar conditions. Take care of your beer and it will take care of you.

Now, let’s take a look at a mini profile of some candidate styles to brew. I have covered these in previous “Style Profile” columns in greater depth, if you want to dig deeper. And after you brew them, check out some food pairing recommendations for each in the story “Perfect Winter Pairings.”

Barleywine

American barleywines are generally more bitter and have a greater hop intensity than the original English barleywines.

Traditionally the richest and strongest of English ales, barleywine is a style that inspired derivatives in Belgium (Bush), the United States (Anchor Foghorn), and elsewhere. Originally a darker beer descended from historical strong Burton ales, paler versions appeared after World War II. The balance was malty and rich with a full body and pleasant alcohol warmth. The finish could be sweet to dry, which often changed with age (becoming drier with age). The balance of hops could vary greatly, which could also affect the impression of sweetness due to the bittering level. 

American barleywines became a distinct style after Sierra Nevada created Bigfoot, which inspired many other highly bittered and hopped strong beers. Double (and stronger) IPAs have mainly replaced American barleywines today in the marketplace, but they have a drier and even hoppier balance. Most current American barleywines exist as barrel-aged products, leaving homebrewers to produce the original versions. Barleywines are much maltier and have a higher finishing gravity than double IPAs, and are meant for sipping rather than drinking. American barleywines traditionally featured the classic American craft C-type hops (Cascade, Centennial, Chinook, and Columbus).

I see the differences between American barleywine and English barleywine as mainly the character of the malt, yeast, and hops, and the intensity of the hops. English barleywines use English ingredients so the base malt is breadier, often with biscuity flavors, while the American version is more neutral. Both may use crystal malts, although English versions are often darker. English hops are more floral and earthy, while American hops more citrusy and piney. Times have changed, and these distinctions are often blurred. English yeast is often fruitier, while American yeast gives a cleaner fermentation profile. American barleywines are generally more bitter and have a greater hop intensity than their
English cousins.

While separating the styles is useful for competition purposes, I often like to play around with different interpretations. I do enjoy the Belgian Bush beer, so sometimes I do the Belgian version. Sometimes I like to mix American and English ingredients. Sometimes I increase crystal malts and use a more complex grain bill to simulate aging, so I can enjoy a “mature” version without having to cellar it as long. Sometimes I add different sugars, candi syrups, or honey to bring in another flavor dimension. If the beer winds up too sweet, I often will add some medium toast oak spirals to add tannins and make the beer seem drier on the palate.

Whatever version you choose to make, start with a high percentage of pale ale malt from that country. Use crystal- or Munich-type malts to increase malt flavors and add color. Use sugar to increase gravity and flavor, if desired. Select hops and yeast from the country of choice. Don’t mash too high, or you risk having the beer seem like a Scottish wee heavy. Be prepared for the flavor profile to change over time as the beer ages. 

Barleywine Recipe

(5 gallons/19 L, all-grain)
OG = 1.097  FG = 1.028
IBU = 70  SRM = 17  ABV = 9.3%

This is kind of a hybrid English/American barleywine.

Ingredients
15 lbs. (6.8 kg) English pale ale malt
1 lb. (454 g) aromatic malt
0.5 lb. (227 g) Carapils® malt
1 lb. (454 g) crystal malt (65 °L) (preferably English)
0.5 lb. (227 g) CaraMunich® III malt
1 lb. (454 g) raw brown sugar
28 AAU Magnum hops (60 min.) (2 oz./57 g at 14% alpha acids)
4.5 AAU Fuggle hops (10 min.) (1 oz./28 g at 4.5% alpha acids)
6 AAU Cascade hops (5 min.) (1 oz./28 g at 6% alpha acids)
2 oz. (57 g) East Kent Goldings hops (whirlpool)
2 oz. (57 g) Styrian Goldings hops (dry hop)
Wyeast 1335 (British Ale II), Omega Yeast OYL-013 (British Ale VI), or LalBrew Nottingham yeast
3⁄4 cup corn sugar (if priming)

Step by Step
This recipe uses reverse osmosis (RO) water. Adjust all brewing water to a pH of 5.5 using phosphoric acid. Add 1 tsp. of calcium chloride to the mash.

This recipe uses an infusion mash. Use enough water to have a moderately thick mash (1.5 qts./lb. or 3.1 L/kg). Mash in the malts at 149 °F (65 °C) and hold for 60 minutes. Begin recirculating, raise the mash temperature to 169 °F (76 °C), and recirculate for 15 minutes.

Sparge slowly and collect 6.5 gallons (24.5 L) of wort. 

Boil the wort for 60 minutes, adding hops at the times indicated. The sugar is added with 15 minutes left
in the boil. Add the whirlpool hops when the heat is turned off. Stir, and wait an additional 15 minutes before chilling.

Chill the wort to 65 °F (18 °C), then oxygenate and pitch the yeast starter or sprinkle two packets of dried yeast. Ferment until complete. After three days, rouse the yeast gently (if necessary) and allow to free rise in temperature up to 70 °F (21 °C) until finished. Dry hop for three days at room temperature.

Rack the beer, prime and bottle condition, or keg and force carbonate.

Barleywine

(5 gallons/19 L, extract with grains)
OG = 1.097  FG = 1.028
IBU = 70  SRM = 17  ABV = 9.3%

Ingredients
11 lbs. (5 kg) Maris Otter liquid malt extract
0.5 lb. (227 g) Carapils® malt
1 lb. (454 g) crystal malt (65 °L) (preferably English)
0.5 lb. (227 g) CaraMunich® III malt
1 lb. (454 g) raw brown sugar
28 AAU Magnum hops (60 min.) (2 oz./57 g at 14% alpha acids)
4.5 AAU Fuggle hops (10 min.) (1 oz./28 g at 4.5% alpha acids)
6 AAU Cascade hops (5 min.) (1 oz./28 g at 6% alpha acids)
2 oz. (57 g) East Kent Goldings hops (whirlpool)
2 oz. (57 g) Styrian Goldings hops (dry hop)
Wyeast 1335 (British Ale II), Omega Yeast OYL-013 (British Ale VI), or LalBrew Nottingham yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Use 6 gallons (23 L) of water in the brew kettle; heat to 158 °F (70 °C).

Place the grains in a mesh bag and steep in the hot water for 30 minutes. Remove the mesh bag, then turn the heat off as the bag drains back into the kettle. 

Add the malt extract and stir thoroughly to dissolve the extract completely. You do not want to feel liquid extract at the bottom of the kettle when stirring with your spoon. Turn the heat back on and bring to a boil. 

Boil the wort for 60 minutes, adding hops at the times indicated. The sugar is added with 15 minutes left in the boil. Add the whirlpool hops when the heat is turned off. Stir, and wait an additional 15 minutes before chilling.

Follow the remainder of the all-grain recipe instructions.

Wheatwine

In addition to being lighter in color and brewed with wheat, wheatwines tend to have less hop character, be more attenuated, and have a drier finish than barleywines.

Wheatwine is a modern American craft invention that seems increasingly hard to find today, and is often a winter seasonal beer that may be wood-aged. The name might lead people to believe that it is a barleywine made with wheat, but it’s quite a bit more involved than that. Many examples play up the “wine” angle, and have a leaner body and lower bitterness rather than being a heavily malty and bitter beer. 

It is more of a scaled up American wheat beer, so the main malt flavors are the grainy, bready flavor of wheat with a more dextrinous body. The yeast character is neutral, so don’t expect the German weizen banana-and-clove flavors. Wheatwines tend to be more attenuated than barleywines, and usually have a dry finish. The increased body provides a filling sensation but this is usually not accompanied by a syrupy or sugary sweetness.

The aromatic qualities of wheatwine features hops less prominently than a barleywine, which allows some of the bready, wheaty aromas to be enjoyed. Hops can be of any variety, but milder floral, spicy, and fruity varieties tend to play better than more aggressive choices. Likewise, the malt can have some additional character, but not at the expense of masking the bready wheat flavors. Light caramel, toast, or honey qualities can add complexity while complementing the base wheat character.

Wheatwine may be oak-aged, which can add some oak, toast, and vanilla flavors, increase the perception of body, and the dryness. If the beer is aged, some light oxidation notes may be present, but should be the more positive Sherry-like notes and not the harsh papery ones. Oak aging adds tannins, which can mellow over time to give the beer a more velvety texture, like in a fine aged red wine. I wouldn’t use oaking in a beer that will be consumed young since it could be perceived as harsher in the short term.

Since a lighter body is desirable, a mash schedule that favors attenuation is appropriate. I tend to use a step mash with this style, and further accentuate the dryness with a sugar addition. The hopping is often aromatic and vinous, so choosing modern varieties that mimic some of the wine-like aromas is a good start. Likewise, if oak aging is used, select woods and toast levels similar to those found in wines.

Wheatwine Recipe

(5 gallons/19 L, all-grain)
OG = 1.102  FG = 1.018
IBU = 51  SRM = 9  ABV = 11.4%

Ingredients
12 lbs. (5.4 kg) German wheat malt
3.5 lbs. (1.6 kg) German Pilsner malt
1 lb. (454 g) flaked wheat
1 lb. (454 g) caramel wheat malt (~50 °L)
0.5 lb. (227 g) honey malt
2 lbs. (907 g) white sugar
21 AAU Magnum hops (60 min.) (1.5 oz./43 g at 14% alpha acids)
1 oz. (28 g) Citra® hops (5 min.)
1 oz. (28 g) Nelson SauvinTM hops (0 min.)
1 oz. (28 g) MotuekaTM hops (0 min.)
White Labs WLP001 (California Ale), Wyeast 1056 (American Ale), or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
This recipe uses reverse osmosis (RO) water. Adjust all brewing water to a pH of 5.5 using phosphoric acid. Add 1 tsp. of calcium chloride to the mash.

This recipe uses a multi-step mash with a mash out. Use enough water to have a moderately thick mash (1.5 qts./lb. or 3.1 L/kg). Mash in all the grains at 104 °F (40 °C) and hold at this temperature for 10 minutes. Raise the temperature by infusion or direct heating to 131 °F (55 °C) for 15 minutes, then raise to 146 °F (63 °C) for 40 minutes, then to 158 °F (70 °C) for 15 minutes. Finally raise to 168 °F (76 °C) for 15 minutes to mash out, recirculating. Sparge with 168 °F (76 °C) water until 6.5 gallons (25 L) of wort is collected. 

Boil the wort for 60 minutes, adding the hops at times indicated in the recipe. Add the sugar in the last 15 minutes of the boil. After adding the final hops when the heat is turned off, let the wort stand for 20 minutes before chilling. Chill to 66 °F (19 °C). 

Oxygenate, then pitch the yeast or sprinkle two packets of dried yeast. Allow the fermentation temperature to rise to no more than 72 °F (22 °C) until fermentation is complete. Rack and allow the beer to drop bright, using crash cooling or fining if necessary. Prime and bottle condition, or keg and force carbonate.

Wheatwine 

(5 gallons/19 L, extract with grains)
OG = 1.102  FG = 1.018
IBU = 51  SRM = 9  ABV = 11.4%

Ingredients
8.5 lbs. (3.9 kg) wheat dried malt extract
1 lb. (454 g) caramel wheat malt (~50 °L)
0.5 lb. (227 g) honey malt
2 lbs. (907 g) white sugar
21 AAU Magnum hops (60 min.) (1.5 oz./43 g at 14% alpha acids)
1 oz. (28 g) Citra® hops (5 min.)
1 oz. (28 g) Nelson SauvinTM hops (0 min.)
1 oz. (28 g) MotuekaTM hops (0 min.)
White Labs WLP001 (California Ale), Wyeast 1056 (American Ale), or SafAle US-05 yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Use 6 gallons (23 L) of water in the brew kettle; heat to 158 °F (70 °C).

Place the grains in a mesh bag, and steep in the hot water for 30 minutes. Remove the mesh bag, then turn the heat off. 

Add the malt extract and stir thoroughly to dissolve the extract completely. You do not want to feel liquid extract at the bottom of the kettle when stirring with your spoon. Turn the heat back on and bring to a boil. Boil the wort for 60 minutes, adding the hops at the times indicated in the recipe. Add the white sugar in the last 15 minutes of the boil.

After adding the final hops when the heat is turned off, let the wort stand for 20 minutes before chilling. Chill to 66 °F (19 °C).

Oxygenate, then pitch the yeast or sprinkle two packets of dried yeast. Allow the fermentation temperature to rise to no more than 72 °F (22 °C) until fermentation is complete. Rack and allow the beer to drop bright, using crash cooling or fining if necessary. 

Prime and bottle condition, or keg and force carbonate.

Imperial Stout

Imperial stout is a style with a wide range of interpretations; they can be dry to sweet, low or high in bitterness, and are often amplified with oak aging or adjuncts.

As with barleywine, imperial stout has an English origin and a modern American story. The style originated in England in the late 1700s as an export beer for the Russian Empire and other countries on the Baltic Sea. The strongest version of the dark stout beer, it eventually fell out of favor before being resurrected in the craft beer era. It basically inspired Baltic porters in the 1800s. As with many styles, American versions started in the modern craft era as copies of English versions and became more Americanized with local ingredients and the craft brewing desire to increase the hop content.

An imperial stout is always very dark, strong, and roasted. The balance can vary quite a bit, with examples ranging from dry to sweet, and the bitterness level varying as well from moderate to high. Given the broad range of ingredients that can contribute to the dark color, and the varying bitterness and dryness levels, the overall flavor profile and balance can be quite broad. This is truly a beer style with a wide range of possible interpretations, and it often serves as a base style for adding
specialty ingredients. 

While no distinction is made in the Beer Judge Certification Program (BJCP) Style Guidelines between English and American variants, commercial examples often do tend to have some differences. English versions tend to be more estery and often have a more tar-like flavor, while American examples can favor more of a late-hop character and clean fermentation profile. Both acceptable, as are those that blend any of these components. In the market, some brewers may tend to identify as one or the other.

Today, many American examples are barrel-aged or involve specialty ingredients. One such example I enjoy is Cigar City Hunahpu Imperial Stout with cinnamon, vanilla, cacao nibs, and chili peppers. During my travels, I often see examples in South America and elsewhere, showing the global reach of modern craft beer. I have had wonderful examples in Brazil that were aged in Amburana wood.

Imperial stout recipes typically include selections from the major groups of base malts, dark malts and grains, crystal malts and sugars, and adjuncts. The major base malt is typically pale ale malt, but could include almost any other type. Dark malts and grains often include roasted barley, but chocolate malt and black malt are also common. Darker-colored crystal malts and brewing sugars provide deeper sugary and fruity flavors. Starchy adjuncts help improve body and mouthfeel. Hops and yeast could be almost anything you choose, as is the overall balance. 

Now that we’ve reviewed these three high-ABV styles perfect for winter, I’ll share a recipe for each on the following pages.

Imperial Stout Recipe

(5 gallons/19 L, all-grain)
OG = 1.097  FG = 1.027
IBU = 70  SRM = 100  ABV = 9.5%

Ingredients
12 lbs. (5.4 kg) U.K. pale ale malt
3 lbs. (1.4 kg) Munich II malt (9 °L)
1 lb. (454 g) flaked oats
1.5 lbs. (680 g) U.K. roasted barley (~550 °L)
1.5 lbs. (680 g) U.K. chocolate malt (~440 °L)
1 lb. (454 g) Carafa® III special malt (~525 °L)
0.5 lb. (227 g) English extra dark crystal malt (~180 °L)
12 AAU U.K. Chinook hops (60 min.) (1 oz./28 g at 12% alpha acids)
1 oz. (28 g) Centennial hops (15 min.) 
1 oz. (28 g) U.K. Golding hops (10 min.) 
1 oz. (28 g) Chinook hops (dry hop)
1 oz. (28 g) Fuggle hops (dry hop) 
Wyeast 1318 (London Ale III), Imperial A38 (Juice), or LalBrew Verdant IPA yeast
3⁄4 cup corn sugar (if priming)

Step by Step
This recipe uses reverse osmosis (RO) water. Adjust all brewing water to a pH of 5.5 using phosphoric acid. Add 1 tsp. of calcium chloride to the mash.

This recipe uses an infusion mash. Use enough water to have a moderately thick mash (1.5 qts./lb. or 3.1 L/kg). Mash in the pale and Munich malts and the oats at 152 °F (66 °C) and hold for 60 minutes. Add the three dark grains and crystal malt, stir, begin recirculating, raise the mash temperature to 169 °F (76 °C), and recirculate for 15 minutes.

Sparge slowly and collect 6.5 gallons (24.5 L) of wort in the brew kettle. Boil the wort for 90 minutes, adding hops at the times indicated in the ingredients list. 

Chill the wort to 64 °F (18 °C), oxygenate then pitch the liquid yeast or sprinkle two packets of dried yeast. Ferment until complete, allowing the temperature to rise as high as 70 °F (21 °C). Dry hop for three days at room temperature.

Rack the beer, prime and bottle condition, or keg and force carbonate.

Imperial Stout 

(5 gallons/19 L, extract with grains)
OG = 1.097  FG = 1.027
IBU = 70  SRM = 100  ABV = 9.5%

Ingredients
11 lbs. (4.7 kg) Maris Otter liquid malt extract
1.5 lbs. (680 g) U.K. roasted barley (~550 °L)
1.5 lbs. (680 g) U.K. chocolate malt (~440 °L)
1 lb. (454 g) Carafa® III special malt (~525 °L)
0.5 lb. (227 g) English extra dark crystal malt (~180 °L)
12 AAU U.K. Chinook hops (60 min.) (1 oz./28 g at 12% alpha acids)
1 oz. (28 g) Centennial hops (15 min.) 
1 oz. (28 g) U.K. Golding hops (10 min.) 
1 oz. (28 g) Chinook hops (dry hop)
1 oz. (28 g) Fuggle hops (dry hop) 
Wyeast 1318 (London Ale III), Imperial A38 (Juice), or LalBrew Verdant IPA yeast
3⁄4 cup corn sugar (if priming)

Step by Step
Use 6 gallons (23 L) of water in the brew kettle; heat to 158 °F (70 °C).

Place the grains in a mesh bag, and steep in the hot water for 30 minutes. Remove the mesh bag, then turn the heat off as the bag drips back into the kettle. 

Add the malt extract and stir thoroughly to dissolve the extract completely. You do not want to feel liquid extract at the bottom of the kettle when stirring with your spoon. Turn the heat back on and bring to a boil. 

Boil the wort for 60 minutes, adding hops at the times indicated in the ingredients list. 

Chill the wort to 64 °F (18 °C), oxygenate, then pitch the liquid yeast or sprinkle two packets of dried yeast. Ferment until complete, allowing the temperature to rise as high as 70 °F (21 °C). Dry hop for three days at room temperature.

Rack the beer, prime and bottle condition, or keg and force carbonate.

Issue: November 2022