Diacetyl rest spørgsmål

[Jens S]

Hej derude,

Jeg har pt mit første forsøg på en lager øl i gang. Det er en tjekkist pilsner og den gærer stille og roligt derudaf ved 11C (gæringen følges vha Tilt i Brewfather). Som det anbefales, har jeg tænkt mig at afslutte gæringen med et diacetyl rest. Jeg er dog blevet lidt i tvivl om det rent praktiske omkring dette.
1) Hvornår udføres diacetyl rest: når FG er nået eller et par point over?
2) Jeg gærer ved 11C. Ved diacetyl rest, sættes temperaturen så direkte op til 19C eller hæves den langsomt?

Jeg håber at kunne få lidt input fra mere erfarne lager bryggere.
Tak
VH
Jens

[clucking]

Jeg bruger normalt nogenlunde anbefalingen fra John Palmer i "How to Brew":

"Diacetyl rest. I like to ferment and lager in glass or plastic carboys, because I can see the activity
in the beer. During fermentation there are clumps of yeast and trub rising and falling in the beer—
it literally looks like it is being stirred with an invisible stick. When you see that kind of activity
slow down, and the bubbling in the airlock slows down, you know it’s time for the diacetyl rest.
To conduct the diacetyl rest, raise the fermentation temperature by 10–15°F (5–10°C) at a rate of
no more than 10°F (6°C) per day towards the end of fermentation when it is about three-quarters
complete. This will be 3-5 days after pitching the yeast, when the airlock activity has slowed from
rapid (~30 bubbles per minute) to a more sedate pace, such as 4-8 bubbles per minute. It can also be
done at the end of fermentation, after airlock activity stops, but works better when the yeast is still
active. Either way, give the yeast enough time to consume diacetyl and acetaldehyde before lagering;
at least four days, if not a week. It will not hurt the beer to wait a week or even two at warmer temperatures before lagering (assuming you have a good airlock)."

[Jens S]

Hej,
Tak for svar. Jeg vil prøve at bruge Palmers anbefaling.

Jens

[Dalmoseosebryg]

Vær opmærksom på at en Tjekkisk godt må have diacetyl