Yeast Oxygen Scavenging (YOS) advice needed

[Brooothru]

Gettin' ready to brew tomorrow and I'm going to incorporate Yeast Oxygen Scavenging into the process. Previously I've used a five minute boil followed by a rapid chill (with stainless steel immersion chiller) to strike temperature followed with 0.65 grams NaMeta added to 9½ gallons (36L) of strike water, then underletting into the grist with minimal gentle stirring and mashing with a mash cap. I think I've made strides in utilizing LoDO techniques and believe my beers have improved greatly because of it. Now I want to take it to the next level using YOS.

I reread the 2016 article on YOS but the only suggestion on dosing was "10 grams dextrose and 10 grams of bread yeast @ 80F". What's unclear to me are dosing rates; i.e., are 10 grams of dextrose and bread yeast the right amount for my 36L of strike water, and does the amount really matter since presumably the yeast will be budding and multiplying. Also curious to me is temperature. 80F seems a bit low, given that most packaged dry yeasts cite something between 95F-104F as the water temperature for reconstituting and proofing.

Additionally it seems to me that it would be a good idea to continue with dosing the strike water with NaMeta for additional O2 mitigation during the mash since yeast scavenging cells will be denatured at saccharin rest temperatures.

Sure would appreciate any and all input from the LoDO gurus on the forum. Cheers!

Brooo Brother

 

[popquizkid]

From my understanding the current recommended dosage rates (for all of the water) are roughly batch size (in gallons) x 2 in grams. So for a 6 gallon batch you would use 12g of yeast and 12g of dextrose in all the brewing water assuming a no sparge mash.

The best information can be found here:

http://www.********************/

This is the guidance from the site:

• Prepare a solution of dextrose and a dry bread yeast at a rate of twice your batch volume in grams (i.e. 5 * 2 = 10 grams each of dry bread yeast and dextrose)
• Ideal timing for dough-in following this treatment of strike water is between 2-3 hours

 

[Brooothru]

From my understanding the current recommended dosage rates (for all of the water) are roughly batch size (in gallons) x 2 in grams. So for a 6 gallon batch you would use 12g of yeast and 12g of dextrose in all the brewing water assuming a no sparge mash.

The best information can be found here:

http://www.********************/

This is the guidance from the site:

• Prepare a solution of dextrose and a dry bread yeast at a rate of twice your batch volume in grams (i.e. 5 * 2 = 10 grams each of dry bread yeast and dextrose)
• Ideal timing for dough-in following this treatment of strike water is between 2-3 hours

Excellent. Just the data I was looking for. I'm assuming "batch" size refers to initial strike water volume and not final beverage volume. I've also gone to no sparge process. Viewing the elapsed time values for D.O. it becomes clear that O2 levels do indeed rebound and begin increasing after 2 hours, so I guess I'll get up two hours early, pitch the dextrose and yeast, then catch an extra "40 winks" before getting down to business with the mash. Sure beats watching water boil, then chilling to pitch temperature, which takes about the same amount of time. Those yeasties can do their work unsupervised.

I did find a reference that confirmed my thoughts on dosing with NaMeta also during the mash, so I'll do that as well. With regards to temperature during YOS, I'll use the recommended water temperature on the manufacturer's label directions rather than an arbitrary 80F.

I don't have a D.O. meter to verify, but the test data certainly make a compelling case as to the efficacy of YOS processing. I'm looking forward to positive results and incorporating it into my brewing bag of tricks.

Brooo Brother

 

[Robert65]

Just to confirm, volume is the volume actually being deoxygenated, and an effective dose is 0.5g per liter of both dextrose and yeast, and so 2g per gallon is close enough for rock n roll. Use a number that's convenient whether you use metric or 'Murican units, it's forgiving. I heat to 90°-100°F, add the dextrose and yeast, cap, and leave either a couple of hours or overnight, whichever is convenient. The yeast will keep scavenging faster that you can pick up more O2 by atmospheric diffusion, and the cap is insurance.

 

[Brooothru]

Just to confirm, volume is the volume actually being deoxygenated, and an effective dose is 0.5g per liter of both dextrose and yeast, and so 2g per gallon is close enough for rock n roll. Use a number that's convenient whether you use metric or 'Murican units, it's forgiving. I heat to 90°-100°F, add the dextrose and yeast, cap, and leave either a couple of hours or overnight, whichever is convenient. The yeast will keep scavenging faster that you can pick up more O2 by atmospheric diffusion, and the cap is insurance.

From the test data I noticed that the DO amounts were still quite low after 7 hours, but had crept up slightly after the three hour mark. Depending on how my "day before" preparations go, I may just start the YOS later this afternoon. We have Friday night plans tonight, but I don't want tomorrow to turn into a lengthy all-day brew session.

Curious if the yeast debris creates any problems in the mash kettle. My setup is electric and the heating coils are at the bottom where the underletting strike water enters the kettle. I get a constant gentle recirculation of wort throughout the mash cycle which should eventually filter out any leftover denatured yeast material, but my concern is possible scorching on the hot coils during the early mash.

De-oxidizing the day before would mean getting a 2 hour head start on Brew Day. It seems like it's taking a whole lot longer to do what I used to accomplish in 4-5 hours, but the beer sure is a whole lot better! A fair trade-off I'd say.

Brooo Brother

 

[Robert65]

I've never seen any effects at all from the yeast. Your water looks cloudy, but it all filters our on recirc and doesn't affect clarity or flavor.

 

[RPh_Guy]

Additional testing revealed that while capped, the water stays de-oxygenated for at least a day, and possibly even up to a week.

I deoxygenate at 95-100°F for at least 90 minutes.

There's no need to add multiple doses of sulfite. Add the entirety of however much you need right before dough-in.

 

[Brooothru]

Additional testing revealed that while capped, the water stays de-oxygenated for at least a day, and possibly even up to a week.

I deoxygenate at 95-100°F for at least 90 minutes.

There's no need to add multiple doses of sulfite. Add the entirety of however much you need right before dough-in.

Sounds great, and good to know info. That's the plan now for this brew session. The next iteration will be whether or not to condition grains before milling. It looks like a worthwhile step but I'm not sure of the risk/reward benefit. That's a variable for the next brew day, however. One step at a time, working out what processes work best with my gear and provide measurable results. BTW, agree with the sulfites. I'm still trying to find the sweet spot of minimum addition and maximum improvement. As I said, it's a work in progress.

Brooo Brother

 

[RPh_Guy]

Hope it works out for you.

I'm still a newbie as well. I recently got an AO sulfite test kit to help track oxygen exposure and to make sure I'm using enough sulfite.

whether or not to condition grains before milling.

Anecdotally, conditioning made a huge improvement in my ease of lautering and I can run my pump at full speed while circulating. That alone makes the extra step worthwhile in my opinion. YMMV.

 

[ba-brewer]

Additional testing revealed that while capped, the water stays de-oxygenated for at least a day, and possibly even up to a week.

I deoxygenate at 95-100°F for at least 90 minutes.

There's no need to add multiple doses of sulfite. Add the entirety of however much you need right before dough-in.

Would you get a week if you de-oxygenated in one of those flexible jugs the no-chills folks use then squeeze out any gas in the head space?

Seem like just doing it in a vessel with a airlock should work too.

edit: Really don't need a week but doing it the night before would help shorten the brew day.

 

[Die_Beerery]

The night before has already been proved and backed up by readings to work.. not sure whys theres a question.

 

[Robert65]

The problem with doing it in any vessel other than the one it will occupy on brewday (MLT, HLT, what have you) is that you'll have to transfer it, which will re-oxygenate it through agitation, splashing, circulation, etc., and you've really gained nothing. But if you can do your YOS in the brew rig and cap it, as @RPh_Guy notes, you'll have plenty of leeway. I find doing it the night before saves all the time I need. I set up for my brew day the night before anyway. Then wake up, put on coffee, and start heating the strike while I go condition and mill the grain (weighed out ahead of time.)

 

[ba-brewer]

I brew outside and have a mobile brewing rig, setting up the night before does not work well for me. A couple hours delay is mostly only an issue during the low light part of the year. Also my schedule is not always under my control.

Thanks for the information.

 

[RPh_Guy]

Yeah I wouldn't really push it that far or use an untested process unless you have a DO meter to confirm it's still deoxygenated.

IMO 90 minutes is fine vs 120 minutes.

 

[Robert65]

Just did mine for tomorrow AM.