DJAllen
Apprentice
Hi all,
Having previously chalked up 30 or so full extract and partial mash BIAB brews without ever falling prey to the curse or oxidation, I've given an unwelcome home to this menace in all of the half dozen or so of my first ever batches of all grain. While I'm one to enjoy working my way through a problem, I'm drawing a blank on the cause and it's tempting me to return to extract and partial BIABs right now. I'd be hugely grateful for any opinions on the following (and most recent) process that's also given me a duff batch of bland wet cardboard flavoured IPA:
Brew - Nelson Sauvin Single Hop IPA. 23 litre/6 gal target fermentation volume, 6.6kg/14.6lb base malt, IBU 52, EBC 14, OG 1.064, FG 1.013, RO/DI water adjusted for mineral balance and pH according to Martin Brungard's Brew'n water spreadsheet.
Process:
1. Mill my own grain while producing DO/RI water
2. Heat required adjusted DO/RI water in 37 litre/10 gal stainless steel boil pot, begin mash using 50 litre/13 gal stainless steel insulated mash tun with drainage spigot. Stir a couple of times during mash.
3. Heat required volume of adjusted DO/RI sparge water while mashing.
4. Batch sparge using high-temp food grade silicon tubing to 30 litre/8 gal plastic carboy until 27 litres/7 gal of wort obtained.
5. Transfer from 30 litre/8 gal plastic carboy via spigot to 37 litre/10 gal stainless steel boil pot using same high-temp food grade silicon tubing.
6. Bring to boil and add copper hops.
7. Add flavour hops and protofloc for last 15 mins.
8. Add aroma hops at flame out and cool to pitching temp (22 degrees C) using copper coil immersion cooler over approx 15 min.
9. Transfer to 30 litre/8 gal plastic carboy via spigot and high-temp food grade silicon tubing and pitch yeast (Nottingham, dry).
9a. (addendum) Aerate wort using plasterer's whisk attached to electric drill.
10. Primary fermentation until max FG obtained (5 days at peak temp 22C/72F day 2, 20C/68F remaining period)
11. Transfer to second 30 litre/8 gal plastic carboy via spigot and high-temp food grade silicon tubing and mix in priming dextrose.
12. Rack to brown glass swing-top bottles using racking cane.
I gave up on transferring to a second 30 litre/8 gal plastic carboy for a 10 day secondary fermentation on the suspicion that O2 in the headspace or the extended period in an O2 permeable HDPE container may be the cause but this did not solve the issue. I also moved to the use of high-temp food grade silicon tubing but to no avail. I'm also very careful to avoid any unnecessary splashing during liquid transfer.
The result - when sampled up to bottling on day 5, it was all you'd expect. After four weeks in the bottle, there are no pronounced flavours, only the stale oxidation. The was equally noticeable but easier to monitor when I was using a secondary fermentation. After the primary, the green beer tasted as you'd expect but, after the secondary, there was a noticeable reduction in expected flavours at the expense of an increase in the stale oxidation taste. After a few weeks in the bottle, there was only the stale oxidation taste.
So here I am. At a loss but hoping you can help. All advice truly welcome.
D
Having previously chalked up 30 or so full extract and partial mash BIAB brews without ever falling prey to the curse or oxidation, I've given an unwelcome home to this menace in all of the half dozen or so of my first ever batches of all grain. While I'm one to enjoy working my way through a problem, I'm drawing a blank on the cause and it's tempting me to return to extract and partial BIABs right now. I'd be hugely grateful for any opinions on the following (and most recent) process that's also given me a duff batch of bland wet cardboard flavoured IPA:
Brew - Nelson Sauvin Single Hop IPA. 23 litre/6 gal target fermentation volume, 6.6kg/14.6lb base malt, IBU 52, EBC 14, OG 1.064, FG 1.013, RO/DI water adjusted for mineral balance and pH according to Martin Brungard's Brew'n water spreadsheet.
Process:
1. Mill my own grain while producing DO/RI water
2. Heat required adjusted DO/RI water in 37 litre/10 gal stainless steel boil pot, begin mash using 50 litre/13 gal stainless steel insulated mash tun with drainage spigot. Stir a couple of times during mash.
3. Heat required volume of adjusted DO/RI sparge water while mashing.
4. Batch sparge using high-temp food grade silicon tubing to 30 litre/8 gal plastic carboy until 27 litres/7 gal of wort obtained.
5. Transfer from 30 litre/8 gal plastic carboy via spigot to 37 litre/10 gal stainless steel boil pot using same high-temp food grade silicon tubing.
6. Bring to boil and add copper hops.
7. Add flavour hops and protofloc for last 15 mins.
8. Add aroma hops at flame out and cool to pitching temp (22 degrees C) using copper coil immersion cooler over approx 15 min.
9. Transfer to 30 litre/8 gal plastic carboy via spigot and high-temp food grade silicon tubing and pitch yeast (Nottingham, dry).
9a. (addendum) Aerate wort using plasterer's whisk attached to electric drill.
10. Primary fermentation until max FG obtained (5 days at peak temp 22C/72F day 2, 20C/68F remaining period)
11. Transfer to second 30 litre/8 gal plastic carboy via spigot and high-temp food grade silicon tubing and mix in priming dextrose.
12. Rack to brown glass swing-top bottles using racking cane.
I gave up on transferring to a second 30 litre/8 gal plastic carboy for a 10 day secondary fermentation on the suspicion that O2 in the headspace or the extended period in an O2 permeable HDPE container may be the cause but this did not solve the issue. I also moved to the use of high-temp food grade silicon tubing but to no avail. I'm also very careful to avoid any unnecessary splashing during liquid transfer.
The result - when sampled up to bottling on day 5, it was all you'd expect. After four weeks in the bottle, there are no pronounced flavours, only the stale oxidation. The was equally noticeable but easier to monitor when I was using a secondary fermentation. After the primary, the green beer tasted as you'd expect but, after the secondary, there was a noticeable reduction in expected flavours at the expense of an increase in the stale oxidation taste. After a few weeks in the bottle, there was only the stale oxidation taste.
So here I am. At a loss but hoping you can help. All advice truly welcome.
D