Fixing diacetyl

Use the Krausen calculator from brewer's friend. Make a starter of that size and gravity, (you don't need the stir plate) when it reaches high krausen chuck it in your keg, purge it a bunch of times and seal it with anywhere from 20-30 PSI. You will not only be cleaning up diacetyl but employing a centuries old German technique to carbonate your beer. The CO2 from the headspace will get absorbed into the beer but by the time it gets close to 10 PSI the natural carbonation from your pitch will take over. It takes around 28-30 PSI to carbonate your keg at room temp. When you Krausen it in the keg in my opinion it doesn't take as long to get carbonated as if you were priming in bottles. I don't think you'll need more than a week. Hook a party tap up after a week and taste it, just be prepared for the explosion of 30 PSI beer coming at you. I would bet it will at least me much better than it was. After that cool it down and let it Lager some more. First pours might have some trub but most likely your beer should be good to go.

I've started doing this to every beer I make now, no more force carbing for me.

Only issue might be you severely underpitched so not 100% sure it will clean up everything but I'm pretty sure it will. I might recommend maybe 2.5-3 packets next time and after one week (ideally close to 1.020) start slowly ramping up to 60 or more.

 

Another German technique is to have a sounding valve on the keg after the Krausen is added, to carbonate at the appropriate pressure for the temperature the keg is at.

 

I have been fortunate to have never had or noticed diacetyl in my beers. I do a rest with every beer except one that I was on vacation at the proper time and still no problem. I am a firm believer that leaving your beer on the yeast three to four weeks is the best thing for your beer. I only pitch one pack of dry yeast when I make a lager never had a problem. Take care!

 

I kept the keg sealed to keep out oxygen. Presumably most of the fernentables were gone. Yeast activity will be limited. This is why the added yeast type makes little different. Anyhow, there won't be much pressure build up from the limited activity. The hope is that the freshly pitched yeast will be actively working on the starter sugars, but when that disappears, they'll begin reducing diacetyl levels. Anyhow, that is my interpretation of what happened when I have done this. It is more expense and waiting, but I ended up turning 5 gallons of something I didn't want into something drinkable.

 

If you use the priming calculator and do it correctly I've never needed the spunding valve. It'll hit the target PSI or sometimes slightly under, easy to adjust with a little head pressure. I personally only use it if I transfer to a keg before terminal. But yeah they are a handy piece of equipment.

 

I see the spell checker changed spunding.

I have a Pils I want to carbonate via Krausening, keeping it cold, and using the spunding valve.

Was going to look for a calculator, I will look that one up.

 

Until you no longer taste diacetyl, plus maybe a few more days so that any new diacetyl precursor made by the starter has had a chance to convert and be taken up by the new yeast.

 

Check it after 7 days. You will most likely be good to go.