Spunding - don't forget your diacetyl rest

[admin]

I have taken to fermenting down to 1.020 and then transferring to sealed corny to finish off fermentation under pressure. Upside is beer comes out carbonated.

But a diacetyl rest is still needed. Turns out you can do this by finishing out at 22 degrees from 1.020, rather than just letting fermentation finish at room temperature.

Fermenting under pressure produces a better flavour profile for lagers in particular where esters aren't desirable,

[Bazza]

Hmmm... interesting idea.

So you just dispense from this corny as normal when fermentation is complete?

I can see a couple of issues:
- Sediment in the first pint or so, that you wouldn't have gotten by force carbonation of fully fermented beer. No biggie.
- With most yeast types and with most regular beer types the gravity will have dropped to 1020 after only a couple of days in the fv, so where would dry-hopping fit into the equation? I'm not sold on dry hopping into the corny as you run the risk of the beer developing a 'grassy' taste over time.
- Unless your batch is 19L or less, you'll still have leftover beer in the fermenter after racking to the corny. Can you bottle the remainder at this stage? Sediment-wise it'll not be much different from priming with sugar, but do you have as much control or idea of how much CO2 will build up in the bottle?

All the above are solve-able. Have you done side-by-side taste comparisons of this technique vs the 'normal' way?


-Barry

[Dr Jacoby]

Fermenting under pressure produces a better flavour profile for lagers in particular where esters aren't desirable,

Does pressure inhibit the production of esters? I didn't realise this. I thought pitching rate and temperature were the key factors.

The German lager brewers usually ferment under pressure to avoid breaking the purity laws (by avoiding the need to introduce artificial carbonation). Maybe inhibiting esters is a fortunate consequence of the same procedure?