Koelsch about to knockout

[brewcrew7]

It's nice to see the numbers, something I wish that the group's paper had included but I'm not going to harp on it to the extent others have...I take it your sparge water was not preboiled as well like the initial strike water? Overall, where would you like to see, or where do you think you can get your O2 levels with your system?

[mchrispen]

Good question. The Brew-Magic is partially hard plumbed and the rest are hoses. I have ordered a full new set of gaskets and o-rings for all of the fittings. I am planning to do a few water runs isolating certain sections to see if I can eliminate most of the O2 ingress. My system is about to hit its 6th service year and there are parts that I have not touched.

The circulation (RIMS) and the lauter processes are where I am most concerned. If I moved to a 20 gallon liquor tank, I could preboil and prep all of the liquor at once. That would remove one step through the cold side pumps. The MLT welded input at the top is not threaded, just a pipe to slip a silicon hose onto. This needs fixing, it leaks, and I am looking at a compression fitting or even a john guest fitting that will seal that up more tightly. The hose is convenient as I can bury it under the mash and fully underlet. I can swap that out for locline for more control on inlet liquor position.

Cold side is a concern as well, I have a few leaks that need to be fixed up. It seems like enough sulfite remains to scavenge a little free O2 in the transfer, but I need to take a lot more measurements and run this a few times. I am definitely rebuilding that side, so I can tighten it all up considerably.

[Owenbräu]

My last lodo kolsch turned out with a lot of sulfur. I pitched at 57F and didn't let it rise above 60F. Same thing happened to me with a hefe too. In hindsight, I'm wondering if ale yeast are going to need to finish with warmer temps to drive off the sulfur. On the next batch, I may let if it hit EVG warm, then transfer to the keg with a bit of krausen instead of transferring cold with 1% extract remaining.

[wobdee]

Do you have a mash cap for your system or were these DO readings from an open system?

[mchrispen]

Measurements were with a lid on the system, but there was a good amount of headspace in the keggle and fermenter.

[wobdee]

OK, thanks. I haven't taken any O2 readings yet on my system (Braumeister) and there's really no way to have a good mash cap for it so I just have a lid with a lot of head space. Maybe not ideal but it seems to be working out alright so far.

[Owenbräu]

Can you float anything in there to reduce the surface area? Maybe glue some foam to the lid to fill headspace?

[wobdee]

[mchrispen]

The Braumeister pumps liquor bottom up and lets the wort flow over the edges of the malt basket (if I recall). I would think with enough steam pressure you would see some reduction in air exposure. That's a pretty cool system btw.

I would guess that a quick CO2 or pure steam sparge before circulation might help a bit, but Henry's laws are hard to overcome. The steam pressure should offset the atmosphere exposure a bit.

[Owenbräu]

What hops did you try in your Kolsch? My last one used Spalt, and I don't think I like them despite the fact they are traditional. It came out very herbal and earthy. I like the fresh flowers and nobles spices of the Hallertaur varieties and Tettnanger much better. Maybe next time I'll skip the FWH and just try them in the boil.