RO confusion... 4 stage, 5 stage, pumped...?

[AdeDunn]

I know some might disagree, but to me, if you are going to adjust water chemistry it's worth considering also getting a magnetic stir plate, Erlenmeyer flasks and giving liquid yeasts a go too. Gives you access to way more yeasts than just SO4 and the like.

 

[The-Engineer-That-Brews]

I know some might disagree, but to me, if you are going to adjust water chemistry it's worth considering also getting a magnetic stir plate, Erlenmeyer flasks and giving liquid yeasts a go too. Gives you access to way more yeasts than just SO4 and the like.

Funny you should mention! Look what just arrived... (and some white labs WL-023, which is now in the fridge) :-))

The things in the packet in the middle are the stir-bars. In the next day or two I'll stick a couple of rare-earth magnets to a PC fan, to stand in for a stir plate

 

[The-Engineer-That-Brews]

Incidentally the inoculation loop handle arrived without ni-chrome wire (grrr) but I have some stainless steel wire so that will have to do

 

[The-Engineer-That-Brews]

Heck, maybe I'll even pitch with a bit of my sourdough starter culture and see what happens

 

[AdeDunn]

There's a guide on here somewhere on building a stir plate. Personally I bought one on ebay. lol

 

[AdeDunn]

Heck, maybe I'll even pitch with a bit of my sourdough starter culture and see what happens

They beat you to it: Sourdough at Wild Beer Co lol

 

[The-Engineer-That-Brews]

That's quite interesting... I do a lot of SD baking, so I always have starter on hand...
SD starters are typically dominated by bacteria (lactobacilli) which kick out a fair amount of either lactic or (if they are stressed) acetic acid, and of course ethanol. They also produce enzymes that break down complex sugars into stuff the yeasts can more easily metabolise.
Generally with SD bread making you're juggling hydration, feeding rate and temperature to balance the lactic vs. acetic acid production to get the level of perceived sourness you want; but you'd have less options on how to do that in the context of a beer wort, I imagine...
I also wonder (because I don't have enough organic chemistry knowledge) whether there is a risk of methanol production?

 

[AdeDunn]

I'd wager that they mixed the sourdough with normal yeast, with the majority of the yeast been normal beer yeast. I used a seasonal old ale blend from Wyeast once that blended Brett with English ale yeast, and this did similar, mostly English ale yeast, with a tiny bit of Brett. The resulting beer was (and still is) delicious (it really is an old ale at this point, at just over 1 year in the bottle). Or they killed the SD after a brief stint, then pitched a normal beer yeast. No idea to be honest, you could try emailing them and asking. lol