Over Oxygenating Wort

[loikar]

Morning all.

When topping up my fermenter I will squeeze the end of the hose to spray it in so to maximise the oxygen.
I think this might me excessive and leaving a twang on the back of the pallet of the final product.

The beer tastes great, but just leaves that lingering twang....not really a kit twang but more like the taste in your mouth 5min after eating one of those sour lollies you get form the Deli.

Just wondering what effects over-oxygenating your wort, prior to pitching has and how much is too much.
My next brew (today or tomorrow) i will just be holding the hose (attached to the pura-tap) above the fermenter and let it splash in. Just as an experiment.

Cheers,

BF

 

[kirem]

As far as I am aware it is almost impossible to over oxygen wort using air. It is possible using pure oxygen. Are you using liquid or activated dried yeast?

There was an 'experiment' done using air versus oxygen. I think by Wyeast, I'll see if I can find the link for you.

http://www.wyeastlab.com/faqs.cfm?website=2#r43

29. What are optimal levels of O2 in wort?

10-15ppm

Back to top >>


30. What is the max level of O2 you can get in a carboy using air?

8 ppm.
Back to top >>


31. Approximately how long do you have to shake a 5 gallon carboy to get oxygen saturation (8ppm)?

45 seconds of vigorous shaking.

Back to top >>


32. How long do you have to run a stone with an aquarium pump to achieve O2 saturation (8ppm) in 5 gallons of wort?

5 minutes.
Back to top >>


33. How do you achieve higher than 8 ppm O2 levels in your wort? .

By injecting pure oxygen into your wort through a stone (1 min for 12 ppm). Or, by flowing pure oxygen into the carboy's head space and shaking for 20 seconds, twice.

 

[rclemmett]

I doubt you could over oxygenate your wort without using pure oxygen.... Whats you method? AG, extract or kit? Sounds like an astringency problem to me. Possibly steeping grains to hot.

 

[hockadays]

is the taste slightly metalic?

 

[Jye]

The beer tastes great, but just leaves that lingering twang....not really a kit twang but more like the taste in your mouth 5min after eating one of those sour lollies you get form the Deli.

Possible lactobacillus infection?

If you are aerating near your grain then some of the dust may be getting in and the lacto starts to ferment before the yeast kicks in. The lacto then stops when the alc gets to high for them.

 

[loikar]

I doubt you could over oxygenate your wort without using pure oxygen.... Whats you method? AG, extract or kit? Sounds like an astringency problem to me. Possibly steeping grains to hot.

It's happened on K&B as well as all K&K. I have an all Extract that I'm waiting on tasting to see if that has it.
It hasn't happened to all my beers, just a few, and some are worse than others.

cheers,

 

[loikar]

is the taste slightly metalic?

Not really, if it was, it would be very very faint.

 

[Adamt]

What sanitiser do you use? Is is sour, acidic or sourly acidic?

 

[loikar]

What sanitiser do you use? Is is sour, acidic or sourly acidic?

Errrrr....never tasted the stuff :icon_vomit:

It's the Brewcraft "no-rinse" Powder, I had a friend give me about 20 pkts of the stuff.
Looks like Napisan (obviously it's not) and fizzing effect in warm water.

My bottles, fermenter are left on the bottle tree for at least 15min to drain\dry before bottling

Cheers,

BF

 

[loikar]

Possible lactobacillus infection?

If you are aerating near your grain then some of the dust may be getting in and the lacto starts to ferment before the yeast kicks in. The lacto then stops when the alc gets to high for them.

Nah, i don't reckon it's an infection. I'm pretty paranoid about my sanitizing.

cheers,

BF

 

[Adamt]

How well are you rinsing your sanitiser after cleaning? By the sounds of it, it is not a no-rinse sanitiser.

 

[rclemmett]

If it is happening to all your brews then it has to be a common element.... Water, fermenter, sanitiser or method. I'd say Adam is right about the rinsing of the sanitiser.

 

[brendanos]

For the sake of your peace of mind, you can bubble air through wort (fish pump, sterile filter, air stone) for 20-30 minutes and you still won't over oxygenate. Simply not possible without pure oxygen.

 

[manticle]

I don't trust no-rinse and I don't see the need if you sanitise right before you brew/bottle.

When I first started kk, the little Coopers packs of sodium met claimed to be no rinse but my brews improved tenfold when I started rinsing.

Try it and see if it makes a difference.

 

[brendanos]

Don't trust no-rinse?! The scientists and scientific evidence are lying to us!!!

If you choose to rinse, make sure it's with sterile water (pre-boiled or otherwise sterile).

 

[mika]

.....
Looks like Napisan (obviously it's not) and fizzing effect in warm water.
.....

You'd be suprised

....
When I first started kk, the little Coopers packs of sodium met claimed to be no rinse but my brews improved tenfold when I started rinsing.
.....

Don't know how they can claim Sod Met as a sanitiser, or as no-rinse. Try a true no-rinse sanitiser and you'll see what no rinse is really all about.

 

[loikar]

I don't trust no-rinse and I don't see the need if you sanitise right before you brew/bottle.

When I first started kk, the little Coopers packs of sodium met claimed to be no rinse but my brews improved tenfold when I started rinsing.

Try it and see if it makes a difference.

Will do,

SWMBO as advised that brewday will not be today as the impending temporary occupation of the inlaws is about to take place.
Will brew tomorrow and feedback in 2 weeks time.

Cheers all,

BF

 

[manticle]

I'm not suggesting my distrust is based on anything other than the crappy k-mart anecdote I outlined above. While I'm aware that it's regarded as the least preferable sanitiser, sodium met works for me and I rinse with tap water. Never had an issue although I have just started playing around with bleach/vinegar solution (still using sod. met to remove the chlorine though as I'm paranoid about my brews tasting like a swimming pool).

If I had a big stainless steel AG set-up type thing I would not be relying on sodium metabisulphite but my current set-up (4 plastic fermenters and a couple of eskies) copes fine with my current practice.

 

[kirem]

Don't know how they can claim Sod Met as a sanitiser, or as no-rinse. Try a true no-rinse sanitiser and you'll see what no rinse is really all about.

A little off-topic, but still useful info.

My knowledge and experience is based around wine, but this information is good for brewing as well.

SO2 is an effective sanitiser, especially for bacteria.

In brewing circles, its' use as a yeast inhibitor is not really appropriate. It's anti-microbial activity is dependent on pH and beer/brewing doesn't have the correct pH range.

If you want to use it as a surface santiser, then you are best to add an acid to push the equilbrium, so you have the required molecular sulphur levels. A spray bottle with SO2 and an acid to bring the pH right down would be a good thing to have on hand.

I know there are other santisers that are better suited to surface sanitisation, but SO2 can be pretty powerful stuff when used correctly. It is always quite dangerous to asthmatics when it has significant molecular SO2.

I wonder why when they supply the PMS or SMS as a surface sanitiser for homebrewers, they don't either advice on the packaging the correct pH range or supply it as PMS+acid mix to add to a certain volume of water, so it is effective. Straight PMS and water is pretty much useless as anti microbial.

We don't normally use SO2 as a surface santiser in a commercial wine environment, per-acetic acid is currently the best practice and I know some breweries use this as well.

I have used SO2 in barrels that are staying empty for a period of time, but always with enough acid (usually tartaric) to get the molecular SO2 up into the right range.

It's use in wine (not winemaking surfaces) is suitable given the pH that wine normally sits at, dependent on variety and style anything from 3.0- 3.6, add enough SO2 and the wine is protected, both microbially and from oxidation. A fermentation that produces acetaldyhe will bind up some of the SO2 and different strains have varying sensitivities.

In beer these pH's don't normally exist, thus the amount of SO2 required to get 0.8ppm molecular would be enormous and you just wouldn't do it.

BUT as a surface sanitiser SO2 can be very effective once pH corrected.

To give 0.8ppm MSO2
pH 3.00 3.10 3.20 3.30 3.40 3.50 3.60 3.70 3.80 3.90 4.00
FSO2(ppm)13.6 17.1 21.5 27.1 34.1 43.0 54.1 68.1 85.7 108.0 135.9

edit: I can't get this to format properly


I would still recommend a different surface santiser other than SO2, but if you have a fair bit of it, add some acid to it to get the pH down and it will do the job. if you need to purchase a santiser go for peracetic acid. http://en.wikipedia.org/wiki/Peracetic_acid

 

[brendanos]

Cheers Kirem that was lovely!