Near-Beer-Engineer
Well-Known Member
I've taken all the steps. Tried all the techniques. Bought all the equipment... But I still get a slight (subtle, but noticeable), off-flavor from my yeast in pale/light beers.
I've been brewing all-grain for years and have made some great beers (including some medal winners) - but the issue of creating completely clean, neutral beers continues to elude me. The "yeast" flavor I'm referring to here is very subtle, and I can only describe it as a slightly cloying "fruitiness" (although fruitiness isn't entirely accurate, it is difficult to put a finger on) that I assume are some esters generated during fermentation. This ester hypothesis was confirmed when I did an experiment that split the wort into 2 batches: one batch was fermented in a SS keg pressurized to 15psi and held at room temperature, the other batch was fermented "normally" in a plastic brew bucket but held at proper fermentation temperatures. Pressurized fermentation is supposed to suppress ester and fusel alcohol production, even at elevated temps. The pressurized batch was completely clean and crisp, while the normal batch had the yeasty off-flavors.
This experiment was on a Blonde Ale. Both batches (pressure fermented vs normal) use the same wort from the same kettle. Below is the recipe and the steps I took:
Yeast Baby Blonde Ale (5.5gal):
Steps I Took To Make Clean Beer:
Nice to see that pressure fermentation has some good effects; however, how do I get that clean flavor without using pressure? Do I need to ferment even cooler? Or am I missing something completely?
Any thoughts are much appreciated!
I've been brewing all-grain for years and have made some great beers (including some medal winners) - but the issue of creating completely clean, neutral beers continues to elude me. The "yeast" flavor I'm referring to here is very subtle, and I can only describe it as a slightly cloying "fruitiness" (although fruitiness isn't entirely accurate, it is difficult to put a finger on) that I assume are some esters generated during fermentation. This ester hypothesis was confirmed when I did an experiment that split the wort into 2 batches: one batch was fermented in a SS keg pressurized to 15psi and held at room temperature, the other batch was fermented "normally" in a plastic brew bucket but held at proper fermentation temperatures. Pressurized fermentation is supposed to suppress ester and fusel alcohol production, even at elevated temps. The pressurized batch was completely clean and crisp, while the normal batch had the yeasty off-flavors.
This experiment was on a Blonde Ale. Both batches (pressure fermented vs normal) use the same wort from the same kettle. Below is the recipe and the steps I took:
Yeast Baby Blonde Ale (5.5gal):
- Malt:
- Pale 2-row - 11lbs (91%)
- Crystal 10 - 0.5lbs (4%)
- Acidulated Malt - 5.6oz (3%)
- Vienna Malt - 2.4oz (1%)
- Hops:
- East Kent Goldings 5%AA - 1oz - 60min
- Yeast
- Escarpment Labs American Ale (American Ale)
- Described as a clean, neutral yeast. I believe this is similar to Wyeast 1056.
- Specs:
- OG: 1.048
- FG: 1.003 (alarmingly low... but confirmed with multiple hydrometer readings on both the pressure and non-pressure ferments)
- IBU: 19
- SRM: 5
- General Process:
- Built ~9gal of soft water profile using distilled H20 (more details below). Mashed at 149F for 60min. Batch sparged with 170F water. Boiled for 60min. Cooled to 65F. Aerated and pitched yeast (from starter). Fermented at 64F for normal batch (room temp for pressurized batch) until FG was stable, about 7 days.
Steps I Took To Make Clean Beer:
- Yeast Starter - made an adequate starter (1.6L @ 1.038, on stir plate) based on the Brewer's Friend calculator. Cold crashed and decanted the starter liquid prior to pitching.
- Water Chemistry - built the water from scratch using about 9gal of distilled H20 and adding 2.7g CaSO4, 5.4g CaCl2, 1.05g MgSO4 and 0.9g NaCl. Also used acidulated malt to keep pH in check.
- Yeast Nutrient - added 1/2tsp to the kettle @ 5min
- Vigorous boil - very vigorous for 60min, no lid
- Cooled rapidly - cooled to 65F with an immersion chiller right after the boil
- Sanitized (obviously) - everything was cleaned with PBW and sanitized with starsan
- Aeration - transfer from the kettle to fermenter is "loud" i.e. it comes out of the spigot and drops about 4 feet through the air into the fermenter, creating lots of splashing and foam. Fermenter is then shook by hand afterwards.
- Controlled Temperature - fermentation of the "normal" batch was held steady on the cooler end of the recommended range at 64F (17.8C) in a temp controlled fridge. Note, the pressure fermented batch wasn't temp controlled at all and turned out much cleaner.
- Clean transfers - transfers to kegs were done via autosyphon into kegs thoroughly purged with CO2.
Nice to see that pressure fermentation has some good effects; however, how do I get that clean flavor without using pressure? Do I need to ferment even cooler? Or am I missing something completely?
Any thoughts are much appreciated!
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