Lowering & raising pH - No Chill & Botulism

[ArcLight]

Any suggestions on the best way to raise the pH of wort, after it's been mashed and boiled and cooled. (i.e. ready for fermentation)

I would like to experiment with storing boiling wort in No Chill Containers for a few months before using. I am concerned about the slight risk of Botulism though. One idea is to acidify the wort with Phosphoric acid, down to a pH of 4.5, which would prevent Botulism from growing.
The problem then is this may (would) impact the enjoyment of the beer. The solution seems to be to raise the pH, but how?

[Note - I use NYC tap water which is quite soft. I also have a jewelers scale that lets me measure small fractions of a gram]

In reading this article:
http://braukaiser.com/wiki/index.php?title=Mash_pH_control#Salt_and_acid_additions_to_the_mash

It seems that Calcium Hydroxide and Sodium Hydroxide, while effective, are hazardous to handle. And Calcium Carbonate would need at least 3-4 ounces and may not dissolve well.

Any suggestions?


[I want to make 10 gallons of Beer at a time, but only drink 5 gallons, and not have the other 5 losing hops flavor and staling]

 

[mabrungard]

So you are looking to obtain the benefit of low pH protection from bacterial infection and you will raise the pH when ready to use the wort as a starter?

In many cases, yeast are tolerant of low pH and would likely ferment that 4.5 pH wort. For a Berliner I made last year, the wort was soured to 3.1 and the US-05 yeast still fermented the wort well. It was not very vigorous, but it worked through it. Raising the wort pH would have been counterproductive in that beer. But there shouldn't really be a problem with neutralizing the acid in the preserved wort with any of the minerals you mention. I don't find that solid NaOH or CaOH are hazardous to handle, but I do use great care. Either would be fine. While chalk is not suitable for adding alkalinity to typical brewing water, the acidity of this preserved wort should react fairly rapidly with chalk. It is a possibility in your case.

 

[ArcLight]

Thank you Martin.
I plan on making an entire batch (5 gallons) not just a starter.
Is it possible to add too much chalk to beer?
If I add 4 ounces, will it settle out in 2 weeks?

 

[g-star]

So you want to stale wort instead of stale beer? This seems misguided to me...if you only want 5 gallons at a time, how about brewing 5 gallons?

 

[RTL]

If food borne botulism is your concern you could simply reboil the second 5G for about 10 minutes, then no-chill again, then pitch as soon as it is at temp. Having said that I think if you are transferring to your no-chill jugs while the wort is still at near boiling temps you shouldn't have any issues. I have been no-chill brewing 20G batches for some time now and I ferment anywhere from 5 to 10G at a time with the other jugs sitting for months sometimes.

 

[ArcLight]

So you want to stale wort instead of stale beer? This seems misguided to me...if you only want 5 gallons at a time, how about brewing 5 gallons?

Becaus ethen I have to spend 5 hours doing that. I'd like to save a brew day if I can.
And what makes you think that 2 month old wort would taste bad?
I've read of brewers who have done this and no one complained about the beer tasting bad.

 

[ArcLight]

If food borne botulism is your concern you could simply reboil the second 5G for about 10 minutes, then no-chill again, then pitch as soon as it is at temp. Having said that I think if you are transferring to your no-chill jugs while the wort is still at near boiling temps you shouldn't have any issues. I have been no-chill brewing 20G batches for some time now and I ferment anywhere from 5 to 10G at a time with the other jugs sitting for months sometimes.

Why would I want to spend over an hour to reboil and chill the beer again?
Then spend more time cleaning up and carrying stuff around. I want to save time, and this would take at least 90 minutes.

As for letting the wort sit for months, unacidified, you are running a small risk of botulism, which can kill not just you, but anyone you share your bee with.

 

[RTL]

I did some more reading on this and it sounds like they do this with some beer kits where the wort they sell is not concentrated like liquid malt extract. They acidify the wort with phosphoric acid then include a small amount of baking soda to add prefermentation to raise the pH back up to regular beer levels.

Also it looks like another alternative would be to raise the temperature of the wort to 80C to denature any botulinum toxin that may have been produced during storage. You don't have to kill the spores just denature the toxin. This could be done via a bucket heater directly in the jug itself. Then recap and put it in your fermentation chamber to cool back down rapidly to pitching temp.

Let us know if you try these, especially the acidification route. Sounds like some people have concerns with flavor stability when using that method.

 

[JonM]

Isn't this the third thread on this very subject?

https://www.homebrewtalk.com/showthread.php?t=562354

https://www.homebrewtalk.com/showthread.php?t=559460

Maybe the mods can merge.

 

[ArcLight]

Let us know if you try these, especially the acidification route. Sounds like some people have concerns with flavor stability when using that method.

That would be a bummer. Where did you read that flavor stability is affected by lowering the pH? Its n't being lowered an insane amount, just from 5.2 to 4.5.

I wouldn't use baking soda. If I try this, it will be with pickling lime.

 

[RTL]

Sorry for the off the cuff replies, that was from my phone. I was mixing what I read with my own conjecture. I was thinking originally that you were being paranoid, and after reading it does appear that this is a realizable concern, even though the probability of occurrence is low. I have been doing no chill for many years now and obviously have never contracted botulism. However one of the articles quoted a food safety expert as saying that this is an accident waiting to happen.

I did see a thread where someone thought that phosphoric acid was causing an off flavor but they didn't really have definitive evidence, they were just spitballing possible causes of a problem.

With regard to flavor stability my concern is that a water profile was targeted and brewed; then an acid is added which needs to be neutralized with something like NaOH, or CaOH. The problem now is that you have added a bunch of calcium or sodium to your existing water profile. Maybe this can be accounted for in the initial recipe design but it might also make targeting mash pH difficult, or may have other unknown affects. I have heard of off flavors from using large amounts of lactic acid so personally I am concerned about adding large amounts of weak acid to enact a significant pH change.

You mention that solubility would be a factor in neutralizing the acid, but I don't think so. LeChateliers principle says that as the base is reacted out by the acid the reaction would be shifted in the forward direction increasing solubility. We would have to worry about common ion effects though since we already have ions in solution from having set a target water profile.

Other considerations with regard to changing pH are the buffer capacity of the wort. If it is high then adding weak acid or base is only going to help in extreme quantity (which could cause flavor change), and can only be verified with a pH meter, which I do not own (not sure about you). The alternative is using strong acid, and strong base, but still may require considerable amount. I think that KOH would probably be the best base. A lot of us use campden tablets and K-meta to treat water for chlorine and there seems to be no concern for how this affects final ion concentrations. I don't know what acid would be best though, HCl would affect our final Cl- concentration and I don't think Br- and I- are good for you in significant doses. Also I'm not sure how to get it since lab supply stores won't ship to residential addresses.

So to summarize I think there are really three options if the wort is going to be stored for long periods of time.

A. Acidify and neutralize while accounting for the overall affect on final ion concentrations in the resulting beer. This would be best tested on two 1G batches. One no-chilled, the other ice bath chilled in the sink. Then fermented side by side and compared with a triple blind study and a decent sample size.

B. Bring the already no-chilled wort back up to 80C for at least 10 minutes to neutralize any toxin formed by the CB, then cool and pitch as soon as possible.

C. Keep the wort refrigerated until ready to use (based on the recommendation for baked potatoes).

The articles I read didn't say not to no-chill beer but did say that it should be pitched as soon as the wort is at or close to pitching temperature, and not to delay. It would be nice to get some data on the effect of hops and alpha acids on C. Botulism bacteria and whether or not high alpha beers would affect there ability to reproduce.

I have to admit I am still skeptical about how concerned we should be. Beer, mead, and wine has been brewed for centuries before wort chilling was invented. I would imagine they just waited until the wort was a reasonable temperature then stirred it with a stick inoculated with yeast. Granted they would presumably be doing this soon after brewing, but also were probably severely under pitching, and didn't have their wort in sealed containers while it was waiting to ferment.

I'm not going to worry about this too much since right now since it is winter and my stored wort is going to be sitting at near freezing in my garage until ready to ferment. However if I get bored I may try option A. above with two 1G batches. I think if I make a significant change to my brewing in the future it would either be to try to get the wort fermenting sooner, and if that failed to buy a heatstick form Bobby to use as a bucket heat and heat the wort in the jugs the day I plan to pitch.

Sorry for the novel.

 

[RTL]

I posted that and re-read it then had a couple more thoughts. I forgot about the other three strong acids, there is HCO3 which would affect final carbonate concentration, HS04 which would affect final sulfate concentration, and finally HNO3. I'm not sure what extra nitrate would do to the beer/wort or the drinker but on the surface it seems like it could be an option if it can be sourced.

Another thought I had is that StarSan is a low pH sanitizer, and they claim that it breaks down into yeast nutrient as it degrades. Adding StarSan to the wort may be a viable option then use KOH to neutralize to whatever extent is desired before pitching. It would be interesting to contact Five Star and see what they think about that idea, and to see what extent the yeast would uptake any sanitizer that wasn't neutralized. I wonder if the 1oz. per 5G that is used normally to make sanitizer could be used directly in wort without resulting in dead bacteria and dead home brewers.

Great, now I'm afraid of my beer, thanks ArcLight!

 

[ArcLight]

Thank you for the detailed reply.
You raise good points. If the buffering capacity is high, I may have to add more Phosphoric acid than I'd like, and maybe that requires more CaOH to neutralize.

I think it would probably be ok to hold back the Ca from the mash and add it to the fermenter, so in the case of adding CaOH I wouldn't add the CaCl.

This may impact the taste.
Hmm.
Maybe it's not as clear cut as i first thought.
I suppose I could experiment with small batches, but I'm not that wedded to storing the extra wort for a few months.

Probably it's easier to make my usual IPAs and use more hops, so even if it degraded it will still be ok.

snip ..
With regard to flavor stability my concern is that a water profile was targeted and brewed; then an acid is added which needs to be neutralized with something like NaOH, or CaOH. The problem now is that you have added a bunch of calcium or sodium to your existing water profile. Maybe this can be accounted for in the initial recipe design but it might also make targeting mash pH difficult, or may have other unknown affects.


Other considerations with regard to changing pH are the buffer capacity of the wort.