Yeast Health

[dreamboat]

I have been feeling that my beers have been generally under attenuating lately, the latest case, an oatmeal stout that has stalled at 1.020 and refuses to budge.

There is a ton of info around, about how to better handle your yeasts to prevent this exact thing occurring.

The first on my list of things to get, has been a reliable system to aerate firstly my starters, and then my wort for the first 12 hours or so after pitching. Boots is getting in some stuff from St. Pats, including a caouple of s/s air stones for me, for this purpose.

The second thing which i am in the process of doing is getting organised with additions for the brew to aid in yeast health. Two things were identified on OCB (thanks to the Guru for his article here) as being important aside from the air, neither of which I have been doing.

Calcium in the mash.
Zinc at the end of the boil.

I have chased up chemical suppliers, and have 500g of Calcium Sulphate, and 500g of Zinc Sulphate on order, to collect mid next week. This stuff is not expensive at all, I am paying about $50 all up (you can probably get it cheaper from other sources) but overall it is not a lot of $$.

I estimate that the calcium will last me for for 1000 brews, and the Zinc 9000 brews. If anybody wants some of either of these, particularly if you are in brisbane, let me know, as i would imagine that in a few years time, I will have two little blocks of concrete, and will have to buy more.
Probably not too difficult to post, but sending white powder in the mail is not really advisable!



dreamboat

 

[JasonY]

Thats a lot of zinc and calcium! I just bought some Wyeast nutrient which I assume has all that stuff but with the advantage of being almost idiot proof

Are you mashing, could be worth checking your thermometers accuracy to make sure you aren't actually mashing at say 70 when you think it is 66? Just an idea.

Your challenge is to use your zink in one year of hard brewing

 

[Batz]

Without sounding like some sort of smart-arse ,
With good airation I can not see why any of this stuff is required?

Well it's not a problem for me at all


Batz h34r:

 

[Asher]

'word' up JasonY
Just what I've been thinking about for the last week
but I'm havint the opposite problem as dreamboat...
My new brewery (ss keg mash tun) seems to be producing extreemly dry beers at my nornal mash temps... prob due to heat losses in the tun.
I've got an American Ale bittered to ~30OBU thats so dry its undrinkably bitter...
Anyone in perth got a keg of underattenuated ale they want to blend?
otherwise its off to the sewer for this septic

Asher for now

 

[ant]

300 IBU? Sounds bitter enough...

 

[JasonY]

Anyone in perth got a keg of underattenuated ale they want to blend?
otherwise its off to the sewer for this septic

May have a Saison stuck at 1.020 ... mash got to 70deg early on hoping it comes down. If it drops enuf I may carb a bit up for next weeks WCB.

Would make an interesting blend. The American ******* Saison

 

[Jethro]

My understanding is that water chemistry varies from area to area so what works with mineral salt adds in brisbane may not in Dampier Melbourne or Perth. Just contact your water authority for analysis to get your starting blocks and work it from there. (Why work blind) I havent got my head around water chemistry myself but I added 1 teaspoon of Gypsum to my mash and ended up with about a 15% increase in mash efficiency.(Maybe thats a cooincidence) Time will tell if the ferment benifits Cheers Jethro B)

 

[Goat]

Is the 'plaster' you buy from Bunnings OK for gypsum ?

 

[Jovial_Monk]

Dunno, I use high quality ag. gypsum, nice and cheap.

Re aeration, it is easy to get totally focussed on initial aeration, but with any beer over say 1045 the second aeration, 14-18 hours afer pitching is just as important.

The yeast buds of madly while there is oxygen in the wort, causing crater marks to exist on all but the last generation of cells, and these cells cannot control what ions and compounds enter or leave the cell. Not healthy. With the second aeration the cells can generate sterols and fatty acids and repair their cell walls.

Think that is crap? I have seen lots of brewers posting to the HBD about how they aerated with pure O2 till the cows came home, then a few days later plaintively asking how to restart a stuck ferment. With a converted bottling tube and a 4 foot drop of the beer at the start, and a smaller drop the next morning the big beers I like to brew attenuate to target in 5 days.

If the ferment is stuck you may need to warm the beer back up to 20C, then rouse the yeast thoroughly to get it back into the beer. In extreme cases pitch champagne yeast

Jovial Monk

 

[THE DRUNK ARAB]

I am with Batz on this one, don't have probs in attenuation. All I do to aerate the beer is drop from a height and pitch a healthy starter.

Dreamboat, are you pitching a big enough starter? Are you brewing High Alcohol beers?

C&B
TDA

 

[Gulf Brewery]

JM says

1. but with any beer over say 1045 the second aeration, 14-18 hours afer pitching is just as important.

2. The yeast buds of madly while there is oxygen in the wort, causing crater marks to exist on all but the last generation of cells, and these cells cannot control what ions and compounds enter or leave the cell.

JM

On 1., Do you have any documented references about aerating at 14 to 18 hours as this subject comes up often and I can't find any decent info on this.

As for 2, the bud marks are reasonably small compared to the overall yeast cell size, so is the bud mark really important?

Yes, the yeast does bud madly while there is oxygen in the wort but all surviving generations of the yeast will convert the wort to alcohol after the oxygen is depleted, not just the last. The last generation of yeast will outnumber the rest (simple maths shows that), Again, is the there any scientific studies that show that "second aeration the cells can generate sterols and fatty acids and repair their cell wall"

Cheers
Pedro

 

[pint of lager]

Dreamboat, I think you are on the right track. There is no gaurantee what worked for me will work for you as of course your water and brewing techniques will vary greatly from mine.

I had the same problem a while back. Stuck ferments and slow ferments. They were 1.040-1.050 og lagers, with 3.5 litre starters. They had been aerated by dropping twice. To deal with these brews (rowsing didn't work), boiled a packet of kit yeast in 1/2 a litre of water for nutrient, cooled, stirred into brew and pitched a packet of saflager in each. They slowly finished fermenting out and were drinkable, but not outstanding.

Long term, I looked towards yeast health, better aeration and salts in the mash. Especially starter health, "healthy parents make healthy children".

All my starter wort has a scrape of a zinc tablet and some dried yeast added to it. Not much of each, as too much zinc is toxic to yeast. Make sure you check the guru's article and put the correct amount in.

All my brews are aerated on and off for at least 8 hours after pitching. All brews (45 litre batch size) have 1 zinc tab and one packet of dried yeast boiled, cooled and added to fermenter. This is done post chilling so that the nutrients avoid being lost in the break material.

Geologically speaking, Australia's soils are old, and many nutrients have been leached out, including zinc. Have heard people discussing zinc defficiencies in areas unrelated to brewing.

The filters that St Pats sell look really good, it looks like you get one with the aeration kit. G+G sell HEPA filters, similar to that as shown in Sosman's pictures somewhere else on this site.

Salts in the mash, use a water analysis from your local water authority and something like promash or beersmith to work out the correct amounts to add. Also, look towards using a combination of calcium sulphate, calcium chloride and calcium carbonate to provide calcium, not just one salt. The ratio of sulphates to chlorides should be I think 2:1 or the other way around. I don't have my brewtexts here.

Hope this helps

 

[Jovial_Monk]

pedro, you do read the HBD occasionally? Especially the Dr Cone posts?

Jovial Monk

 

[Jovial_Monk]

Nutrients, hmmmm

yup boil some yeast in the wort boil, but, really, wort has all the yeast needs for good health. don't trust the guru, do some reading

Jovial Monk

 

[Gulf Brewery]

pedro, you do read the HBD occasionally? Especially the Dr Cone posts?

Yep, read that every day. When Dr Cone last did a Q & A in 2003, there were a few questions about oxygen levels requried. I can't find any reference to addding oxygen later.

One of the interesting comments that he made in 1999 was "The
ideal time to add the oxygen for repitched yeast is at the very beginning.
The ideal time to add the oxygen for Active Dry Beer Yeast is after about
the 14th hour for Ale and 24th hour for Lager."

So I am still looking for some definitive info on adding oxygen some hours after the yeast is pitched.

Cheers
Pedro

 

[Jovial_Monk]

keep on looking!

Jovial Monk