Gose: A Modern Take on an Ancient Style
“Gose” is a German word and is pronounced “GO-zah.” The beer is named after the river Gose that runs through the town of Goslar where the beer originated. Gose was first brewed somewhere around 1,000 years ago in the small town that was just springing up near the silver mines of Rammelsberg Mountain in the Harz region of lower Saxony. Those early Goslarian ales were probably significantly different from the Gose we are drinking today. The original Goslar beer was almost certainly spontaneously fermented by multiple kinds of Saccharomyces as well as lactic acid bacteria, Brettanomyces, other wild yeast, and probably even a bit of Acetobacter if the beer was left to age. With the exception of the brewing kettle, almost all the brewing equipment back then would have been made of wood. That mixed culture lived in the wood vessels that were used for brewing and fermenting the beer.
The brewing process was very different from that of today; brewers did not sparge the mash and if they boiled the wort at all it was not for very long. We can be almost positive it was brewed with a spice mix and not with hops. During the medieval period, hops were not yet used in brewing — most beers were brewed with a mixture of spices (sometimes referred to as gruit).
There were two main styles of beer back then; a strong alcoholic brown beer brewed with gruit spices, and a low-alcohol white beer usually made with some portion of wheat. These two beers were very different. The brown beers were between 7–9% ABV and the alcohol and herbs helped to preserve it. Beers of that strength (that were sometimes fortified with intoxicating herbs) were too alcoholic and expensive (due to higher malt requirements) to be consumed throughout the day. For daily consumption, brewers made the lighter white beers that were between 2–5% ABV. They had neither sufficient alcohol nor many spices to help preserve them and so would sour quite quickly. They were often made with malt that was not kilned but left to “air dry” in the sun or the attic. The lack of kilning lead to a malt that produced a cloudy beer very light in color and that lacked the bready flavors we normally associate with beer. These beers were often served within 48 hours of brewing and as they aged over the next week or two the sourness would increase. Gose was one of these white beers and, of them all, it has the longest lineage. Most of these white beers have passed on into history and of those few that do remain (Berliner weiss, Belgian wit, Broyhan, and Grodziskie), Gose predates them all.
Gose’s long and meandering history, over the thousand or so years took it from Goslar to Leipzig and beyond. For several hundred years Gose’s renown spread throughout the region and most of the neighboring towns started to emulate the style. Soon there was the original Goslarian Gose, but also a Halberstadt Gose, a Blankenburger Gose, Aschersleber Gose, Wernigeroder Gose, Leipzig Gose, and many others. Gose became so popular as an export from Hamburg in the 1300s that they put a special tax on it and other foreign beers to keep it from outselling the local beers. Gose’s popularity grew mostly to the south to Leipzig, where Gose became the beer of the town. Gose taverns started popping up all over Saxony. At one point in the 1800s there were over 80 licensed Gose taverns in and around Leipzig. Leipzig and Gose were almost synonymous for more than 200 years. World Wars I and II were turbulent in Germany and especially hard on Gose. Gose’s final decline started in the late 1950s a few years after the communist party took over East Germany. The communist government had very little interest in promoting regional cultures, their focus was on all things relating to mother Russia. The government started to nationalize local breweries giving control over to the state run Volkseigener Betrieb (VEB). As VEB took control they were not interested in making a niche sour beer from the Saxon region of Germany, their focus was on making industrial lagers for the proletariat. By the late 1960s Gose had vanished from the beer landscape.
A Gose revitalization
Gose’s story might have ended there were it not for the efforts of two gentlemen; Lothar Goldhahn and Dr. Hartmut Hennebach. Goldhahn had been a restaurateur until the communist government came along and re-assigned him to the job of book binder (a job he had little fondness for). He dreamed of opening his own restaurant. In 1985, Goldhahn read an article in a local newspaper about Leipzig’s Gose culture during the 18th and 19th centuries.
He conceived to re-open the old Gose tavern named Ohne Bedenken, to restore it to its former glory of the late 1800s, but the job would not be an easy one. A large part of the beer garden had been damaged in bombings during the war. After the Communist party’s takeover of East Germany in 1949 the Ohne Bedenken fell on hard times. Goldhahn would not only have to get permission from the Communist government (private businesses were not the norm) and he would also have to invest over 3,000 hours of his time to restore the tavern and restaurant.
One day in 1985 while searching for Gose memorabilia at a swap meet, Goldhahn met Dr. Hartmut Hennebach, a former biologist who was selling off his small collection of things related to the history of Leipzig. They began talking about Leipzig and its rich history and soon they became friends. Herr Goldhahn, assisted by Dr. Hennebach, began doing extensive research about Gose and the Gose taverns and eventually felt that they had come up with a traditional Gose recipe for their new endeavor.
They decided that once open they would split the duties; Goldhahn would oversee brewing and Hennebach would oversee the tavern operations. Goldhahn felt strongly that the new Gose should be brewed in Leipzig but no local brewery wanted anything to do with this odd, top-fermented sour beer. In 1985, he convinced the Schultheiss Berliner-Weisse-Brauerei in East Berlin to brew a Gose for them. The Gose Ohne Bedenken re-opened in May of 1986 to great reviews and enthusiasm quickly spread. Then came the fall of the Berlin wall and for a time the Ohne Bedenken Gose tavern flourished. By the mid-1990s it was so popular that it was impossible to even get in the building without a reservation.
In 1999, homebrewer-turned-pro, Tilo Jänichen and Adolf Goedecke (the great great grandson of the Ritterguts Gose brewery owner) formed a venture to again brew the Ritterguts Gose. They produced the beer according to the Rittergut Gose profile from 1824 and they were lucky enough to find a few old bottles of beer from which they could culture yeast and Lactobacillus to use in the fermentation.1 They started brewing at the Microbrewery Leipzig but soon moved production to the Brauerei Reichenbrand.
Some other breweries started brewing their own Goses as well but the style remained almost unheard of as recently as the early part of the second decade of this century. In early 2012 Westbrook Brewing released their interpretation of a Leipzig Gose. It was the first release of a Gose that got any real traction in the US, and for many, this was their introduction to the style. As brewers and consumers became more familiar with the style a fascination with sour beers began to grow. This fascination would soon turn into a full-blown movement. Gose would rise from the brink of extinction to a commonplace offering. Gose’s popularity has been driven by many factors; drinkability, being a great palate for other flavors, by consumers desires for “anything new,” and by ease of production.
Characteristics of a Traditional Gose
The flavors, aromas, and other characteristics that we will get into are for Gose beers made without additional flavorings such as non-traditional spices or fruits. The fact that Gose-style beers easily lend themselves to being flavored with spices or fruits makes it difficult to cover all possible flavor variations here.
Starting & Finishing Gravities
Goses are not big beers, so your starting gravity should be no higher than about 1.057 (14 °P), and could be as low as 1.032 (8 °P). A typical starting gravity for Gose is about 1.040 (10 °P).
Gose should finish dry, between 1.005–1.012 (1.25–3 °P). Typically final gravities should be about 1.008 (2 °P).
Acidity & pH
Since acidity is such a big part of Gose’s flavor, we will discuss it before looking at the other specifications. Acidity is the main thing that has defined the beer style since its beginning. And as such, one needs to know a little about acidity, how it is measured, and how it works.
Acidity is the effective strength of an acid (or a base) in solution. We use the pH scale to measure that concentration. For the more scientifically minded, pH is the negative log of the activity of free, dissociated hydrogen ions (H+) in an aqueous solution.
Brewers have been using the pH scale since soon after it was developed at the Carlsberg laboratories in Denmark in 1909. The “p” stands for “power of” or “potential of” and the “H” stands for hydrogen, and is a measurement of hydrogen ions in a concentration. The pH scale runs from zero (very acidic) to 14 (very alkaline or base) with a measurement of 7.0 being neutral. Pure distilled water is pH 7. Thus a pH below 7 is acid, and a pH above 7 is alkaline.
The pH scale is logarithmic, and uses an exponent of 10. Each increase or decrease of 1.0 on the scale indicates a ten-fold change of pH. Thus a solution of pH 4 is 10 times more acidic than a solution of pH 5 and 100 times more acidic than a solution of pH 6. Remember the lower the number from 7, the more acidic it is.
Temperature will affect pH. All pH readings should be taken at or calibrated to a temperature of 77 °F (25 °C). As the temperature rises, pH decreases. For example at 32 °F (0 °C), the pH of pure water is an alkaline 7.47. At 77 °F (25 °C), its pH is a neutral 7.00, and at 212 °F (100 °C) its pH is an acidic 6.14. Be sure to adjust your pH reading accordingly if your solution is greater or less than 77 °F (25 °C).
The pH range for most finished, non-soured beers runs between pH 4.0 and 4.5. For sour beers the range will run about pH 2.9 to 3.9. Sourness in Goses should complement the overall beer, falling between 3.2 and 3.6. It should produce a lively and bright acidity, not a mouth-puckering sourness.
Flavors
Gose is a tart wheat beer with low bitterness and a restrained touch of seasoning — most often that seasoning is coriander. This beer is brewed with both barley and wheat in equal amounts and the flavor reflects this mix. The beer should have a light bready flavor and aroma. The beer also has a mild salinity (discussed later). The overall impression from the salt should be a light mineral quality and not one of saltiness. Gose-style beers usually have a high level of carbonation and a bright acidity. This tart acidity is the result of lactic acid and this is often described as a lemon or citrus tartness. Bitterness should be low and generally go unnoticed.
Bitterness
Bitterness should be between 5 and 15 IBUs — although some brewers in the US have produced hoppy Gose-style beers. The hoppy versions fall far outside the guidelines of the Leipzig-Gose tradition. I find that the acidity of Gose clashes with a high bitterness and that clash interferes with the thirst quenching drinkability of the style.
Gose-style beers have bright, sharp flavors that make them refreshing to drink. They are highly attenuated and should finish dry and crisp, never full-bodied or flabby. The restrained acidity and sourness should balance the bready, doughy, wheat malt character.
Aroma
Gose-style beer aromas are often light to moderately fruity. The malt aroma is reminiscent of sourdough bread dough. There may be a cider quality to the overall aroma. The use of coriander can give the beer a floral and sometimes lemony note. These coriander notes, when mingled with the fruitiness and sourness, create a pleasing aroma. Hop aroma should be low and when noticeable should complement the other aromatic components. The fermentation (both bacterial and yeast) should be clean, with no to very low levels of “funkiness.” The aromatic qualities should be mild to moderate and should blend together to create an overall impression of being fresh and spritely.
Color
The color of Gose should be relatively pale; very light straw to medium amber color, in the range of 1.5 to 6.0 SRM (3 to 12 EBC). Traditionally they were called white beers — a term that came from the use of “air dried” malts that are not commercially available today. The color might be a little higher if a brewer decides to use a small amount of specialty malt, but this would not be considered traditional.
Goses are unfiltered wheat beers and as such some haze is acceptable. They will be hazier than modern German-style Pilsners but they should not be as hazy as a hefeweizen nor a modern New England IPA. They should be in the range of about 8–25 Turbidity Units (NTU), but they could be as low as 4 to as high as 600 NTU. They definitely should not be milky or opaque.
Mouthfeel
The body of these beers is light to medium-full. The overall impression for these beers should not be heavy. High carbonation levels lend a pleasing effervescence, on the higher side of 2.5–3.0 volumes. It may have a good head from the wheat, but due to lactic acid fermentation, some may also have very little foam at all. The issue of low foam can be rectified by starting wort souring at a pH less than 4.5 (or lowering very quickly to below pH 4.5). This will help keep the protease enzymes that cause foam degradation from being active.
Alcohol
The alcohol by volume (ABV) on these beers is fairly low, between 3 and 5 percent. This corresponds to the low original and finishing gravities mentioned earlier.
Ingredients
Many things play a part in the formation of the final beer’s flavors: Specific processes, time, cleanliness, equipment design, the brewer’s skill, and ingredients. None can be more important than good ingredients, particularly the water and the yeast you will use. Without good ingredients it is very difficult to make delicious beer.
Malt
Malt for Goses should be pale in color. Traditional Goses are made using 50% barley and 50% wheat. These proportions can vary some, but keep in mind that Goses are wheat beers and as such should have a relatively high percentage of wheat malt. Since wheat is a naked grain (no husk) this may cause problems in lautering. To rectify this problem a brewer can use a small percentage of rice hulls (5–10 %). Sometimes a small amount of oats can be used (about 10%).
Hops
Goses are not hop-forward beers. One reason that Goses are not hoppy beers is that Lactobacillus is not a hop-tolerant bacteria. As little as 5 IBUs can affect the growth of Lactobacillus, and without Lactobacillus, Goses will not be sour. This is less of an issue if you are doing a brewhouse souring of your Gose, but still keep in mind that Goses are light beers that are balanced and refreshing. Too much hop bitterness will throw these light beers out of balance.
Salt
It has been suggested that the salinity in Gose beer once came from the mineral-laden water of the River Gose. Today we know that not to be the case. Unlike other regions of the world at that time, salt was plentiful in the area around Goslar, and thus was not the expensive commodity it was in other brewing centers. We do know that brewers have at times added salt to enhance body and fullness of their beers. These reasons are probably why salt was first used in Goses. We know that later as the beers from Goslar gained in popularity, brewers in the nearby towns wanted to emulate their unique character. In order to replicate the Goslar’s famous Gose flavor, brewers needed to replicate that mineral salinity. From brewing records, we know that the solution for many of those brewers was to add a little salt.
There are many varieties of salt, and you probably should decide what kind of salt you want to use before you decide how much of it you want to use. Salt’s chemical makeup, in its purest form, is sodium chloride (NaCl) in a 2:3 ratio of sodium and chloride ions by weight. Thus 100 g of sodium chloride (salt) contains 39.34 grams sodium and 60.66 grams chloride. Minerals or compounds bound up with the salt are what gives different salts different flavors and colors. There are many varieties of salt to choose from, but once a salt is dissolved in either food or beer, it is pretty unlikely that any difference could be easily distinguished. The mineral content in most salts is so low that any effect these minerals might have on flavor will be lost when even as much as 1 oz. (28 g) is mixed into one gallon (3.8 L) of beer. This leads me to believe that the value of using an esoteric and expensive salt in a Gose would be almost entirely marketing. For brewing Gose I would suggest an affordable non-iodized sea salt.
I believe that in most of brewing, more can often end up being less. It’s a tricky thing; one wants the ingredient to be noticeable, but only enough to make the beer interesting. Salt’s flavor contribution should accentuate other flavors and enhance mouthfeel, not create a salty brew. For some historical perspective, we know that some Goses from the early twentieth century had between 130 and 280 ppm of salt. At Anderson Valley Brewing Company we use a bit more; about 800 ppm of hydrated salt added post fermentation. While this is more than some historical examples, it is below the threshold of where it would negatively affect the beer. This gives our Goses a noticeable salinity but certainly not a salty taste.
Spices
Hops were not yet in use when Goses were first brewed in the Middle Ages. There were, instead, many herbs and spices used in brewing beer. There may have been many spices once used in making Goses but the two that are most noted in historical records are coriander and sometimes spruce. Of these two, coriander is the one that remained in use even up into the 20th century. Regardless of what (if any) spices a brewer chooses to use, a spice’s contribution to the overall beer should be in a supporting role. You want to add enough spice to lightly accent the beer, but not overpower the other flavors.
Fruit
Fruit was not traditionally added to Gose, but as with Berliner weiss, flavored syrups were sometimes added to the beer at the point of service. Modern brewers have taken that concept and run with it by adding fruits, both natural and as purees, syrups, or flavorings, to the beers before packaging. The potential flavor combinations are nearly limitless.
The fruit a brewer adds will contribute flavor, but also some fermentables. Most fruits contain a mixture of sugars: Fructose, glucose, and sucrose. The pH of fruit can vary from 4.5 to as low as 2.1 for some citrus fruits. You should bear this in mind when adding fruit to beer. In the case of Gose, a fruit addition might even raise the pH.
Fruit may also bring color to the beer. Most of these colors will be pleasing, but not all. Be careful when using fruits that contain seeds, pits, or skins. These parts of the fruit can cause unpleasant astringency or off-flavors. I recommend tasting these components by themselves and deciding if you think it worth the extra effort of removing them from the fruit. The rind, peel, skin, and seeds can contain compounds that impart harsh and unwanted flavors — sometimes even toxins. In most cases, I think it is worth the trouble to peel, pit, or de-seed the fruits.
In my experience fresh fruit almost always tastes best, but fresh fruit has many drawbacks. It is labor-intensive to process; peeling, squeezing, zesting, chopping, pureeing, scooping, and mixing. It can be hard to acquire a sufficient amount (when out of season), and it does not store well.
Other options include (in descending order of my own preference) frozen whole fruit, frozen purees, frozen pasteurized purees, pasteurized juice, pasteurized aseptic non-frozen purees, juices, juice concentrates, extracts, natural flavoring, and artificial flavorings. Each of these has pros and cons. As you descend down that list from frozen whole fruit to artificial flavoring, the quality of the flavor decreases as the ease of use increases. One nice thing about using purees, juices, or extracts is they have removed most of the extraneous matter (seeds, pits, stems, etc.). Whichever of these forms you choose, be careful to find a vendor with flavors that you like; puree, juice, syrup, and extract can vary widely in flavor and aroma from one supplier to the next.
Hot-Side Fruit Additions
The advantage to adding your fruits on the hot -side is that they are sterilized by contact with the hot wort. The downside is that there may be a loss of some of the subtle and more delicate flavors and aromas during the boil, whirlpool, or steeping. Boiling fruit may also create a more cooked jam-like flavor. As with spices, the best way to add fruit on the hot-side is at the very end of the boil — just long enough to sterilize the fruit in the whirlpool.
Cold-Side Fruit Additions
Adding fresh fruit to your beer on the cold-side can give your beer the flavors closest to real, fresh fruit. As with spices, the downside to adding fruit at this time is that it has not been sterilized. Fresh fruit has a lot more both micro and macro fauna. Adding fresh fruit to beer on the cold-side may dramatically increase your chances of infection. To alleviate some of this potential, brewers often use frozen fruit, as most bacteria cannot survive any length of time in a deep freeze — but some can. Safer yet are flash-pasteurized fruit purees that have then been frozen, and even safer are fruit concentrates.
The earlier in fermentation you add your fruit, the more fruit flavor and aroma is lost to carbon dioxide creation during fermentation. Adding the fruit when fermentation is very near the end or completely finished will preserve the aroma and flavor. If the yeast are dormant or removed this may leave fruit sugar in your beer. This additional fruit sugar will not only make the beer sweeter, it will leave unfermented sugar in the beer, which can lead to infections, gushing bottles or foaming kegs, or worse — exploding bottles or cans.
If a brewer wants to get fruit flavor and aroma, but does not want the sweetness from the fruit sugar, add the fruit in the last 20–30 percent of fermentation and this will allow the yeast to consume most of that sugar.
Yeast
For Gose, the choice of yeast is not as dramatic as for other beers. Goses are traditionally top-fermented ales, so although lager yeast could be used, it is not the best choice. I would recommend a German ale strain — perhaps a Kölsch or altbier yeast. One could also use an English ale yeast, but I would avoid ones that are overly fruity. Pick a yeast that ferments dry and with a low fruitiness. Kveik yeast would be an interesting choice and make a good Gose.
Bacteria
Lactic acid is one of the defining flavor characters of the Gose style. The lactic acid in the beer is derived from lactic acid bacteria (LAB). The Lactobacillale (LAB) family include Lactobacillus, Pediococcus, Lactococcus, Leuconostoc as well as several other lesser-known varieties.
Lactobacillus is the most used and most known and understood of the LAB. Lactobacillus can be found throughout nature on fruits, plant material and grain husks, in human and animal mouths, and in digestive tracts and skin. The genus Lactobacillus contains around 180 known species. Lactobacillus is commonly used in the production of many foods including yogurt, cheese, cocoa, fermented vegetables like pickles, sauerkraut, and kimchi, sourdough bread, some aged meats, some sour beers, and some wines. When selecting a variety for souring your beer the main selection criteria should be flavor. Other considerations might be speed of production, hop tolerance, temperature range, and byproducts that may affect other bacteria or your yeast’s metabolism. Most species of Lactobacillus are not hop-tolerant. Some of the more common choices of Lactobacillus are:
L. delbrueckii: Often used in yogurt production, it is a clean, lactic sourness. Known for heat tolerance.
L. Acidophilus: Heterofermentive, micro aerophilic, used in soured dairy products like yogurt. Known to inhibit other organisms’ growth.
L. Plantarium: Aerotolerant, will grow at lower temperatures of about 60 °F (16 °C) and has some difficulty performing above 115 °F (45 °C). Heterofermentive, it can produce other byproducts (CO2, alcohol, acetic acid). Does not like hops. Very high tolerance to low pH (~3.0).
L. Sanfranciscensis: Important in sourdough production, it produces doughy notes.
L. buchneri: Heterofermentive, may produce acetic acid.
L. Casei: Has a wide pH and temperature range. Used in cheese production. Ferments lactose, maltose, and sucrose.
The source for your LAB can vary as well. Most people get their bacteria from a laboratory like White Labs or Wyeast. Some choose to pitch live active yogurt into their beer. Others use probiotics like Good Bellies. And a few use the LAB that exist on grains to sour their beer. This later is a tried-and-true method known in Germany as Sauergut. Whatever the source you decide to use for your bacteria, it is very important that you make a starter and grow up a proper amount to pitch into your wort. The amount should be similar to the proper yeast-pitching rate for a wort — approximately one million cells per milliliter per degree Plato of the beer. The optimal temperature range for LAB to grow is 95–120 °F (37–49 °C).
Souring the Beer
There are many methods for souring beer, some of them easier, others more complicated. I will discuss a general method, but keep in mind that one could improvise and there can be many variations on this theme. Originally, a thousand or so years ago, Gose was spontaneously fermented. Today a few brewers choose to sour the beer in a co-fermentation by pitching both bacteria and yeast during their cellar operations, but by far, most brewers produce Goses using a brewhouse souring process.
Brewhouse Souring
Brewhouse (or kettle) souring is usually done in the brew kettle. There are several methods and we will discuss the details a little bit later, but they all begin in the same way. The mash is completed as one would in normal brewhouse operations. The wort is then separated from the grain, it is run into the kettle and cooled to the proper temperature (between 95–120 °F/35–49 °C). Then, a source of Lactobacillus bacteria is pitched into the wort. The wort is held at a temperature of 95–120 °F (35–49 °C) and the Lactobacillus is allowed to produce lactic acid until the desired pH is achieved. At that point the wort can be boiled like a normal brew. The bacteria are killed by the heat of boiling, and the wort can then be transferred into a fermenter.
The advantages of kettle souring, as opposed to post-kettle souring, are several. First, the soured wort gets boiled before being transferred to fermentation, thus no live Lactobacillus bacteria is sent into the cellar. Second, it enables you to fix the level of acidity desired with a high degree of accuracy. Third, if desired you can add a little more hop bitterness to your beer. This can be done during the boil because the usually hop-intolerant Lactobacillus has already done the souring prior to your hop additions. It is important to remember that as little as 5 IBUs can retard Lactobacillus growth, and that Gose traditionally are not hoppy beers.
Oxygen Exclusion
The reason that kettle souring of the wort is superior to sour mashing is that the mash contains a lot of bacteria that can produce some pretty unpleasant aromas in beer. In order for these bacteria to produce these notes they need two things; a high pH (above pH 5), and oxygen. Without these two vital things these “bad” bacteria cannot carry out their life functions and produce unwanted aromas. To eliminate these two things a brewer needs to get the wort off of the grain (thereby greatly reducing the amount of oxygen and bad bacteria in contact with the wort), and begin the souring process as fast as possible so as to lower the pH below 5.
Removing the wort from an oxygen source is probably the more important of the two. The kettle dimensions provide less surface area to air (oxygen) ratio. Some brewers go a step further and either purge their kettle with a gas that will displace the air (like carbon dioxide, nitrogen, or argon) or put a “blanket” of those gases on top of the wort as the kettle fills and during the souring. Some brewers even do both. Getting the wort into the kettle, purging it with gas and/or blanketing the wort with gas will all help to exclude oxygen from your process.
Lowering the pH
There are several options to lowering the pH below 5 as soon as possible. The easiest is to add some food-grade lactic acid to the kettle as you run off your wort — just enough to adjust the pH down to 4.9. The other way to lower the pH quickly is to pitch the proper amount of LAB into the wort so it begins souring it fast. In either case you will need to lower the temperature of the wort from around 150 °F (65.5 °C) to the optimal range for LAB growth (95 –120 °F/37–49 °C). This can be done in several ways: You can create a wort with a higher gravity than is ultimately desired and add cooler water to the wort in the kettle to cool it down. Or you could run the wort through a heat exchanger to cool it to the proper temperature. What you should not do is wait for it to cool on its own.
Other options
For brewers who do not want, for whatever reason, to go through the process of a bacterial fermentation, there are other options.
Lactic Acid Addition
A brewer could simply add lactic acid to the wort or beer. The advantage of this method of souring is that it is simple. It can even be done post fermentation, thus leaving your yeast happy and healthy, and there is no danger of infecting any of your other beers with Lactobacillus. Unfortunately, there can be several problems associated with this method of souring your beer. The flavor is not the same as a bacterial fermentation; many people, myself included, assert that sour beers made this way are less complex and less interesting. They do not have the depth of flavor that one might hope to taste in a Gose. Also, concentrated lactic acid can be very syrupy and it can be hard to mix into wort or beer, especially in cold, finished beer. For these reasons, I recommend that you avoid simply mixing lactic acid into beer for your souring.
Acidulated Malts
Acidulated malts can be added to the grain bill to bring the pH down. The advantage to this souring method is that it is very easy, and since no live bacteria are involved, there is no greater risk of infecting other beers than you would have with a regular mash. The disadvantage to this method is that it does not bring the pH down as much as some brewers would like. That is unless you use a prodigious amount of acidulated malt, and this will have flavor impact that people would find undesirable. Acidulated malt is basically Pilsner malt with lactic acid added to the surface, so problems could arise with starch conversion if one used acid malt to drive pH lower than 4.8. Most recommendations for using acidulated malts is in the 1–10% range of the grist.
A brewer could always combine two or more of the above methods to create an acceptable souring process and add an acidity that fits your brewery and your beer. In the end it is all about finding the method or methods that work best for you and creating the beer you want.
If you are interested in more details about Gose and techniques for souring beer you can find them in the book Gose: Brewing a Traditional German Beer for the Modern Era.
Resource:
1 McGregor, Nacy, and McGregor Christopher. 2017. “So the Story Goes – The Story of Gose.” Brauwelt International.
Gold Hammer Gose
(5 gallons/19 L, all-grain)
OG = 1.040 FG = 1.006
IBU = 8 SRM = 3 ABV = 4.3%
This is a straightforward recipe for a classic, refreshing Gose.
Ingredients
5.25 lbs. (2.4 kg) pale barley malt
2.8 lbs. (1.3 kg) red wheat malt
~2 oz. (57 g) rice hulls
1.9 AAU Chinook hops (45 min.) (0.15 oz./4 g at 12.8% alpha acids)
0.02 oz. (0.4 g) Indian coriander (fine ground) (0 min.)
0.62 oz. (17.6 g) sea salt
Lactobacillus culture, such as Wyeast 5335, White Labs WLP672, or WildBrew™ Sour Pitch
White Labs WLP029 (German Ale/Kölsch) or Wyeast 1007 (German Ale) or SafAle K-97 yeast
3⁄4 cup corn sugar (if priming)
Step by step
Mash in at 154 °F (68 °C) with the grains and rice hulls. Rest 60 minutes and lauter. As the kettle fills, begin to introduce an inert gas (usually nitrogen, but CO2 works well too) into the top of the kettle. Stop runoff at 1.008. Once the wort is in the kettle, mix in cooled water to achieve a temperature of 118 °F (48 °C) — or recommended pitch temperature from the manufacturer — and a gravity of about 1.034. Add Lactobacillus propagation. Pitching rate is ~500 mL at 1 x 108 cells per mL (or approximately 5 x 1010 total). Hold at the recommended souring temperature. Allow to sour to desired pH (between 3.3–3.5). Once the pH is reached, boil the wort for 45 minutes, adding hops at beginning of the boil and the coriander at the end.
Pitch German ale yeast at 68–70 °F (20–21°C). At the end of fermentation add the fully hydrated salt solution at a rate of 0.124 oz. per gallon (0.92 g/L). Bottle and prime or keg and force carbonate as usual.
Extract only option: Rice hulls are not needed. Swap out the pale and wheat malts for 2.2 lbs. (1 kg) wheat dried malt extract and 2 lbs. (0.91 kg) extra light dried malt extract. Heat 23 qts. (22 L) to 180 °F (82 °C) and stir in the dried malt extract. Hold at this temperature for 15 minutes for pasteurization, then cool wort to Lacto pitching temperature. Follow all-grain instructions for the remainder of the steps.
Anderson Valley Brewing Co.’s Blood Orange Gose clone
(5 gallons/19 L, all-grain)
OG = 1.038 FG = 1.005
IBU = 12 SRM = 3 ABV = 4.4%
Anderson Valley has become well-known for their variety of fruited Goses. This example uses blood orange juice that imparts tangy citrus notes that complement the Champagne-like flavors.
Ingredients
5.5 lbs. (2.5 kg) 2-row pale malt
2.4 lbs. (1.1 kg) malted white wheat
~2 oz. (57 g) rice hulls
0.43 lb. (195 g) blood orange juice concentrate
3.3 AAU Nugget hops (60 min) (0.25 oz./7g at 13.1% alpha acids)
0.016 oz. (0.45 g) Indian coriander (fine ground) (5 min.)
0.61 oz. (17.2 g) sea salt
Lactobacillus culture, such as Wyeast 5335, White Labs WLP672, or WildBrew™ Sour Pitch
White Labs WLP029 (German Ale/Kölsch) or Wyeast 1007 (German Ale) or SafAle K-97 yeast
3⁄4 cup corn sugar (if priming)
Step by step
Mash in at 150 °F (66 °C) with the grains and rice hulls. Rest 60 minutes and lauter as normal. As the kettle fills, begin to introduce an inert gas (usually nitrogen, but CO2 works well too) into the top of the kettle. Stop runoff at 1.008. Once the wort is in the kettle, mix in cooled water to achieve a temperature of 118 °F (48 °C) — or recommended pitch temperature from the manufacturer — and a gravity of about 1.034. Add Lactobacillus propagation. Pitching rate is ~500 mL at 1 x 108 cells per mL (or approximately 5 x 1010 total). Allow to sour to desired pH (between 3.3–3.4). Hold at the recommended souring temperature. Once the pH is reached, boil the wort for 45 minutes, adding hops at beginning of the boil and the coriander at the end.
Pitch German ale yeast at 68–70 °F (20–21°C). Add the blood orange juice concentrate near the end of active fermentation. At the end of fermentation add the fully hydrated salt solution. Bottle and prime or keg and force carbonate as usual.
Extract only option: Rice hulls are not needed. Swap out the pale and wheat malts for 2.2 lbs. (1 kg) wheat dried malt extract and 2 lbs. (0.91 kg) extra light dried malt extract. Heat 23 qts. (22 L) to 180 °F (82 °C) and stir in the dried malt extract. Hold at this temperature for 15 minutes for pasteurization, then cool wort to Lacto pitching temperature. Follow all-grain instructions for the remainder of the steps.
