Yellow Galaxy, #2 of our OP Series

As we told you in the tasting of our first Oat Pale Ale, we loved it so much that we decided to begin a new series of beers, called OP Series. These beers would share some common characteristics, like being more or less clear in color, having a considerable amount of malted oats, with a good amount of hops both in the whirlpool and dry hop and with a low ABV percentage. For our second recipe of this series, the name of the beer could give you some clues about some of the changes we made from the original recipe. While for our OP Series #1 we used East Kent Goldings as bittering hops and Citra during whirlpool and for dry hopping, in this one we used another British hop for bitterness, Fuggles, and the combination of Galaxy and Amarillo for the additions for flavor and aroma… and in this case for the name of the beer also (Amarillo meaning yellow in Spanish). The rest of the recipe was almost the same. For the grist, half Pilsen, half naked malted oats and for the yeast, Vermont Ale. But in this case the producers were different, so there could be some small differences in the products this time compared with the ones we used previously. For OP Series #1 Pilsen malt was from Dingemans and in this case it was from Grannaria. Yeast was from Giga Yeast for #1 and it would be from The Yeast bay for #2.

Calcium chloride for water treatment

This time we also treated water for the mash, aiming for a suitable pH value. To do this, we collected the water we needed the day before brewing day, boiled it for a few minutes and we left it all the night to evaporate chlorine. On brewday, we added enough sulfuric acid and calcium chloride to achieve a mash pH value around 5.30. These additions would also give us a chloride:sulfate ratio of 1:1, the same we had with OP Series #1. You can see the amount of the different ingredients and details from the process below.


2.60 Kg (5.73 lbs) (50.0%) Pilsen base malt (Grannaria) (5.0 EBC)
2.60 Kg (5.73 lbs) (50.0%) naked malted oats (Crisp) (3.0 EBC)
60.00 g (2.12 oz) Fuggles (4.50% AA) pellets (boil 30 minutes, 27.6 IBUs)
50.00 g (1.76 oz) Amarillo (7.90% AA) pellets (whirpool 15 minutes at 80ºC (176ºF), 5,9 IBUs)
50.00 g (1.76 oz) Galaxy (15.60% AA) pellets (whirlpool 15 minutes at 80ºC (176ºF), 11.6 IBUs)
50.00 g (1.76 oz) Amarillo (15.60% AA) pellets (dry hop, 8 days after pitching yeast, for 3 days)
Vermont Ale (The Yeast Bay)  (1 vial, pitched directly without starter)
Volume: 21.00 L (5.5 gallons)    OG: 1.044   FG: 1.010     ABV: 4.4%     IBUs: 45,0     Color: 7.6 EBC     BU/GU: 1.034     Efficiency: 65.00%
Ca: 114 ppm; Mg: 3 ppm; Na: 7 ppm; SO4: 143 ppm; Cl: 147 ppm
69.0ºC (156.2ºF) for 60 minutes
60 minutes


During brewday, mashing went as expected, with a temperature of about 69ºC-70ºC (156.2ºF-158.0ºF) all the time, with some mixing in between. Pre-boil gravity, as it happened the last time, was less than expected (1.028 versus a theoretical value of 1.036). I had the theory that the problem was an insufficient crushing of malted oats, being that those grains are smaller than malted barley. And with the experience of subsequent elaborations with this ingredient, it turned out to be true. Nowadays we crush malted oats with a corona mill so we end with a finer crush for these grains.

No problems with boiling either. We added the bittering hop charge as we had planned and, after one hour, we cooled the wort to around 89ºC (192ºF). At that time we added 50 g (1.76 oz) of Galaxy pellets and 50 g (1.76 oz) of Amarillo pellets for a 15 minutes whirlpool, after which temperature dropped to 80ºC (176ºF). After that, we remove hops and we cooled the wort to 20ºC (68ºF) with a copper immersion chiller, then pitched yeast directly from the vial (Vermont Ale from The Yeast Bay). Probably it would have been better to make a starter, but due to a lack of time that wasn’t possible. We put the Brewbucket fermenter in the fermentation chamber, set at 18ºC (64.4ºF), aiming for a fermentation temperature of 19ºC-20ºC (66.2ºF-68.0ºF). Original gravity was 1.036 (theoretical value was 1.044).

Dry hopping with Amarillo hop pellets

It took a couple of days to show signs of active fermentation, with some bubbles in the airlock and a temperature rise 48 hours after pitching. The rise in temperature continued for one day more, reaching 20ºC (68ºF). Fermentation activity started to slow down four days after pitching. We raise the fermentation chamber temperature to 20ºC to force the yeast to eat the remaining sugars and we left it that way for two days. Then we set the fermentation chamber temperature at 15.5ºC (59.9ºF) before dry hopping with 50 g (1.76 oz) of Amarillo pellets in a hop spider. The next days we lowered the temperature progressively until the beer reached 10.5ºC (50.9ºF)

Vermont Ale, chosen yeast for our OP Series#2

We brewed this beer for a day with longtime friends, so we were going to keg most of it and, if there was something left, we would bottle it. Eleven days after brewday, we transferred 18 liters (4.76 gallons) of beer to a corny keg while purging with CO2. After that, we force carbonated it and kept the keg at 5ºC (41ºF) until it was time to take it to the reunion. We still had 1.8 liters of beer, so we bottled it in 5 33 cL (12 fl. oz) bottles. We bottled with enough sugar to get a carbonation level of 2.5 volumes of CO2. Final gravity was 1.014, somewhat higher than the one estimated by Beersmith, giving a final ABV of 3%, nothing that worried us.

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