Acidulated malt to be separate from the rest of the bill. Cool to 20°C, pitch yeast in primary fermenter. Primary for 5-7 days, then secondary. Add lime, calamansi, and lemongrass in secondary.
For the Gose style, the typical carbonation level is between 2.6 and 3.3 volumes of CO2. At 4°C (39°F), you can aim for around 2.8 to 3.0 volumes of CO2, which will provide a pleasant level of carbonation that complements the style's tartness and enhances its drinkability.
For a Gose, the mash pH before adding the acidulated malt should be around 5.2 to 5.4. This is a typical range for most beer styles, ensuring proper enzymatic activity during the mash for efficient conversion of starches to sugars.
After adding the acidulated malt, the mash pH should be slightly lower, in the range of 4.5 to 4.8. This lower pH will help accentuate the tartness and brightness of the Gose style. Note that the final beer pH for a Gose is usually around 3.2 to 3.6, which is achieved through the combination of acidulated malt and lactic acid-producing bacteria, such as Lactobacillus.
For the recipe provided, we used OYL-200 Tropical IPA yeast. This yeast strain typically works well at fermentation temperatures between 70°F (21°C) and 85°F (29°C), with the ideal temperature being around 72°F (22°C) to 75°F (24°C) for optimal fermentation and flavor development.
After fermentation is complete, you can keg your Gose. The ideal temperature for kegging and serving most beer styles, including Gose, is between 38°F (3°C) and 45°F (7°C). This temperature range ensures that the beer is properly carbonated and the flavors are well balanced.
You should add the ingredients to the fermenter during the secondary fermentation stage. This is typically 7-10 days after the initial fermentation begins, or when the primary fermentation has slowed down significantly. This ensures that the initial fermentation has completed most of its work, and the added ingredients will not interfere with the yeast's activity.
To add the ingredients to the fermenter:
Prepare the ingredients: For citrus zest and lemongrass, wash the fruits thoroughly and remove the zest using a zester or peeler, being careful to avoid the white pith. For lemongrass, cut off the bottom part and remove the outer leaves. Cut the lemongrass stalk into smaller pieces.
Sanitize the ingredients: To avoid introducing any unwanted microorganisms, you can briefly soak the ingredients in a no-rinse sanitizer solution (like Star San) before adding them to the fermenter. Alternatively, you can use a technique called "dry hopping" by putting the sanitized ingredients in a sanitized mesh bag or hop sock, which will allow the flavors to infuse while keeping the ingredients contained.
Add the ingredients to the fermenter: Open the fermenter, carefully add the ingredients (either loose or in the mesh bag), and close the fermenter. It's essential to minimize exposure to air during this process to reduce the risk of oxidation.
Allow the secondary fermentation to proceed: The ingredients should remain in the fermenter for 5-7 days to extract their flavors fully. You can taste the beer periodically to check if the desired flavor intensity has been reached.
Remove the ingredients (if using a mesh bag) and proceed to the next step in your brewing process, which is typically cold crashing, fining, and packaging (kegging or bottling).
Boiling the juice and lemongrass before adding them to the secondary fermentation can indeed affect the flavor. The heat can cause some of the volatile aroma compounds in the citrus juice and lemongrass to be lost or altered, which could result in less fresh, vibrant flavors.
However, boiling can also help to sanitize the ingredients, reducing the risk of introducing unwanted microorganisms into the beer. If you choose to boil the juice and lemongrass, you can do so for a short period, such as 5-10 minutes, to minimize flavor loss while still benefiting from the sanitizing effect.
Another option is to pasteurize the juice and lemongrass at a lower temperature (around 160°F/71°C) for a longer period (about 10-15 minutes). This method can help maintain more of the fresh flavors while still providing some degree of sanitization.
In either case, make sure to cool the boiled or pasteurized mixture to fermentation temperature before adding it to the fermenter to avoid shocking the yeast or causing temperature fluctuations that could affect the fermentation process.