Can out of whack pH prevent fermentation from finishing?

[Yankeehillbrewer]

A few months ago I decided to pull the trigger on brewing an extreme beer. My goal was to make a 20% or better ABV beer, somewhat in the realm of Utopias. Not very original, but I wanted to see if I could do it. Well, apparantly my brewing prowess is not what I think it is. Fermentation has stopped dead and I can't figure out why. I suspect that the pH may have gotten to a point that the yeast just can't handle it, but IDFK.

This brew consisted of about 80% Malt, with the remaining 20% being Maple Syrup,Brown Sugar & Corn Sugar. My first pitch of yeast was a 3500mL starter of WLP001 with an appropriate amount of yeast nutrient. OG was 1.154, this was just from the Grains & Corn Sugar. The Maple Syrup and Brown Sugar would be added in stages later on. After 15 days, I added the first dose of Maple Sugar(1qt) and a 1800mL starter of WLP099, super high gravity yeast plus more nutrient. Gravity was at 1.073, and this addition took it up to 1.090. After another 15 days, I repeated this, but used a 3000mL starter of WLP099. Gravity at this point was 1.060 and this addition took it up to 1.075.

Unfortuntely I forgot to hold back some WLP099 after the second pitch and couldn't make another starter. I also seemed to forget to keep taking notes. I did add the Brown Sugar in, but at this point the thing won't ferment anymore and is sitting at 1.080. I did pitch a pack of turbo distillers yeast that is supposed to be good to 23% ABV, but it didn't budge.

It seems like yeast is dying the minute it hits the fermenter. I mashed at 146 and with all the simple sugars in there it should have fermented like crazy. One thing that I haven't done, and can't do is hit it with oxygen. I don't have an O2 stone. Could it be as simple as just racking it to another fermenter and letting it splash real vigorous so it gets some aeration?(I didn't even consider it until I was typing this out) Also, I don't have a pH meter, I tried strips but that seems pointless.

I apologize for the short story, but I'm not ready to give up on this thing yet.

Thanks for reading

 

[ajdelange]

There are many things which need to be considered in high gravity brewing. pH is one of them but pH needs to be considered at any level of OG. I'm guessing that pH is probably not your problem but rather yeast stress and perhaps the sugar spectrum (i.e. higher long sugar/maltose/glucose ratio than desired. Do control for pH however. I have no reason to believe that the 5.4-5.5 mash pH and below 5 in the fermenter working down to 4.3 - 4.6 as the fermentation completes shouldn't work for high gravity brews as well as they do for more normal ones. But I've done precious few high gravity brews so hope that some people with more experience with this will respond here.

 

[SpeedYellow]

Wow, at an OG of 1.154 you are waaaaaaaaaaaaay outside the norm. There's a whole new realm of stuff to worry about with an extreme beer like that, and pH would probably be at the bottom of the list.

 

[Wynne-R]

Mostly off-topic, a guy in my homebrew club described his brew as having OG 1.300. He said he couldn’t be sure, because the hydrometer was laying on it’s side.

The bigger the beer, the weirder the problems. I'm with you, SpeedYellow. Maybe you should sneak up on your target with progressively stronger batches.

 

[Yankeehillbrewer]

I think I'm just going to try and get a couple more viles of WLP099, make a giant starter and then just rack the beer to a fresh fermenter. The more I think about it, lack of O2 in solution seems to make more sense than whacked out pH. Hopefully I can take a stab at it next weekend if I can get some yeast this weekend.

 

[indianaroller]

In my experience, mash Ph has an effect in attenuation. This would be more of a problem with such a high starting gravity. Just a thought.