pH and yield improvements

[bt1]

Howdy,

while still sober on Chrissy day a few observations of late.

From previous posts you may be aware I'm a bit of a nutter for yeast nutrition, types, testing, conditions, reading. Don't get me wrong here I occasionally use Lowans especially when there's no quality issue to be gained like quick TPW neutral wash. If your not the type of brewer who likes to inquire and try things this is not a read for you.

Bought a proper new pH meter a few months back as old one was getting to need calibration every few days...didn't know they drift out of calibration with repeated use they sure as hell do.

These comments are based on approx. 12 brews over recent weeks and while I stand by them, results will vary by area due to issues like starting water pH so without testing your own location its just a guide to what's happening.

settled on using bicarb as it's available near every where , cheap and works. Other carbonates like chalk are very effective but dam hard to find as a food grade. Appreciate the variation between initial vs. perm alkalinity however.

Sugar/Grain UJSM variants and few Bundaberg food grade molasses washes and 4 x TPW's
Initial start temp: 29c-32 ...don't for get to re calc pH for temp correction.
Water: 7.1 ( Adelaide summer tap water, rested for 2 hours before use)
Initial starts: approx. UJSM's 6.8pH, molasses 6.5pH, TPW's approx. 5.5pH
2 hours fermenting ( after yeast stir in and growth stages) all seem to drop a full 1- 1.5 pts
Next day dropped by a good 2.5 - 4 pts.
The UJSM variants have a notable drop with typical 6.8 start with a running pH of as low as 3.7pH. The slow start molasses washes really do fire up with the addition of bi carb...it seems partly a solution to the typical lag these washes seem to have.

By gradually raising the pH over a couple of hours, avoiding yeast shock, with dissolved bi carb stirred in (1 heaped teaspoon in a warm pint of water x 3 doses) you'll recover .5 - .8pts no biggy,but does get them all around to mid to high 4's. Well and truly in the sour mash range, under any ammonia development that's commonly discussed on the greater than 5.5pH level. No bacterial infections in any. Btw did try to induce an ammonia wash once at about 6.2 pH...never happened.

Now here's the funky things
yeast activity makes a notable jump after adding bi carb and is sustained for a good day.
We're getting far better sugar use with hydrometers showing very low .90's or even flat .88's a drop of around .4 -6 pts on hydro at least. great result imho
ferment time is almost a 1/2 faster than expected.

The real bonus is the yield we're getting at least 20% - 25% better yield than unmeasured previous results. This may sound a little subjective and it is at this stage cos I've not recorded enough imho to be definitive, but I can say this is a notable result change and very happy with it.

This is a consistent result wether using the CM type still, old hybrid pot and unsure as yet too early on the 6 x perf plater. This view is also the same as previous posts made on starting pH and folk going way too low on pH scale especially for TPW's when citric is also added. These washes start low enough.

There's clearly a couple of schools of thinking on pH as a factor. Some see no value in measuring or adjusting and that's fine, no probs as they get a result they're happy with.
For me having invested the effort and time to build a new 6 perf plater in search of better spirit quality it's logical to invest some time and effort for the inputs to a wash as well. While a good still is a nice to have ...it's just one of several issues we need to come to grips with imho.

For inspiration and a further read if interested try John Palmers How to Brew site or Beersmith site

So ends my Xmas contribution for your post lunch snooze.

bt1

[bluess57]

Interesting experiments there bt1
BTW HBS sell calcium carbonate -Coppertun brand, usual inflated prices.

[bt1]

thanks blues,

will hit up local HBS next visit

bt1

[MattyC]

Interesting post :) :idea:

[Lupus]

Interesting reading BT1. I can see the benefit of optimizing the conditions so that the yeasts can perform to it's best potential.

A couple of questions though.
1) constant checking increases the potential of wash infection. Got a way around this? Using a wine thief?

2) is the increased alcohol produced of equivalent quality? There have been comments that the use of turboes increases yield but has a higher chance of producing off flavors. Does this occur here?

I was thinking of studying the fermentation process as well, checking wash temp and SG as the ferment occurs, seeing if there is s sweet spot for the washes. Will post more when I get my sensors.

[bt1]

Howdy,

On wash infection, unless using low sugar say 1kg, backset generators I've never had an issue. I've no issue with this either as all I want is a quick 2 day back set boil from it to speed up sour mash generations...3 per week is no drama.
While fermenting I don't use an air lock, only after the active ferment has finished. There's enough C02 coming out to fix just about anything.

No change in quality at all...just allowing yeasts to push up to 12-14% instead of 9 - 10%...on a Bakers yeast more with specialist yeasts and mid week feeds of Epsom and DAP...

bt1

[bt1]

ok,
a couple more to add to this..

2 x Bundaberg molasses 28lt rum washes std recipe nothing special, near finished minimal activity...likely <1 day left to go. pH 3.8 and hydro showing just on 1.000 piss poor imho there's sugar to be had in them there fermenters.

Same process as described above, 3 x shots of bi carb, minimal Epsom and DAP also added. Off they go again after 30 mins, hydro now in the getting close range .95 - .96 with approx. a day to go..extended ferment due to refix imho. pH pushed up to 4.4.

I'm fast becoming convinced that mid ferment adjustments for pH and feeding up, gets ALL the sugars presented in a wash and finishes around 1 on a hydro are just less than ideal wash management.

a near believer,
bt1

[MacStill]

Hydrometer readings in a molasses wash will never be anywhere near normal, if your getting 1.000 your doing better than the rest of the world can ;-)

Too many unfermentables in molasses to get it to 990, it's just not going to happen and is well documented.

Just putting my experiences out there so noobs dont get the wrong info mate, I've run finished molasses wash at 1040 and had fantastic yield ;-)

[bt1]

Yep,

your right Mac..I've fucked up the figures I provided...those figs in second post are for the Sugar/grain wash...Oops!

retested just now @26c rum wash is sitting at 1150.

The mid week feed up and pH fixes are still the go I reckon as it extends the ferment time by a good 2~ish days. process was the same for all 5 fermenters.

get a note pad in future
bt1

[bt1]

hold the phone

I'm having a real fuck up on this...that reading should be

1020 not 11~ish

it's going to be one of those days...
bt1

[Lupus]

Bt1
Out of curiosity, bicarbonate you are using, is that baking soda?

Any difference using potassium bicarbonate as used in wine making?

Just like using citric acid vs something like tartaric acid in wine making. Is there any difference? After all, we are just using these to balance pH rather than adding flavour. Although, the use of citric acid in wine making can add a citrus flavour in wine making?

Starting to look at adjuncts to fermentation now on the next step of my learning.


Sent from my iPad using Tapatalk HD

[ilanrl]

Hey BT1

Have you considered the possibility that its not the pH adjustments that are reinvigorating your yeast but just that you stirred up the wash?

From my beer brewing days I know that 'racking' the beer restarts the ferment. Just stirring and getting the settled yeast back in suspension is great for kick starting a sluggish ferment. You need to do the test double blind - that is doing the exact same test wth out actually adding in anything (other than water) to adjust pH. It may just be the placebo effect!

lou

[bt1]

I've always done a mid week rev up.

But it don't explain the yield gain.

Could do a series of un touched but frankly I'm rather enjoying getting .5 - .75 lt @90+ abv for free.

bt1

[B-Man]

I know this might be necroing a thread but its too good a thread to not continue.
If adding bicarb does wonders why do all recipes call for adding citric acid?

[Wellsy]

Bran the citric is usually added so the sugar can be inverted by using it.

[Todd]

Adding acid lowers the starting ph.

I've read somewhere that a lower starting ph (~5) helps prevent infections as other organisms can't handle it as well yeast can. So the yeast has a better opportunity to grow without competition. Later the yeast will influence the pH causing it to decrease further. This is when you would want to bring it back up or at least prevent it getting too low.

Also people seem to recommend calcium carbonate over sodium bicarb as evidently sodium salts will affect the flavour of the wash.