Pitching yeast

[Notsob17]

What is the proper way to pitch yeast? I have always mixed a pack of yeast in about 8oz warm water. Let it sit for about half an hour and then pour it in. I saw a post on here recently where the user mentioned aerating the mash before pitching to avoid a slow fermentation? Obviously a newby here. Thanks

[still_stirrin]

Hey...its best to do both...rehydrate your yeast AND aerate the wash.

Dry yeast has had all the moisture removed in processing. To minimize damage to the cells, rehydration in warm water is the best thing to do. It allows the cells to fill and restore the moisture to the cell walls. Then, pitching in sweet wort/wash won't be as likely to cause the osmotic pressures to crush the cells.

The reproduction phase of yeast (budding) is aerobic, which requires oxygen. Aerating the wash will inject oxygen into it for the yeast. Good oxygen at this phase of their lifecycle will help growth of healthy yeast and your ferment will be quicker and finish cleaner.

Make sense?
ss

[Notsob17]

Thanks. Do i stir it in good when i pitch it? And then once daily im assuming?

Im working on a 1st gen Ujssm right now and its going slow it seems. Had to replace hydrometer and it wont be in until thursday for me to check.

[still_stirrin]

Don't need to stir the ferment once its started. Its OK to stir when you pitch the yeast (probably not really necessary, especially if you make a starter). But don't stir after that. Leave it closed with an airlock if that's how you ferment.
ss

[rad14701]

What is the proper way to pitch yeast? I have always mixed a pack of yeast in about 8oz warm water. Let it sit for about half an hour and then pour it in. I saw a post on here recently where the user mentioned aerating the mash before pitching to avoid a slow fermentation? Obviously a newby here. Thanks

Mixing yeast in water is just rehydrating it from its dry state but there would be very little colony growth...

If you want to make a starter so you are pitching a lot more mature yeast you also either need a tablespoon of sugar in a bit more warm water or use warm wash... You'll need a substantially larger container because it'll really take off and you may need to stir it down a few times to avoid overflow... I shoot for 30 minutes so I mix once I know the wash will be down to pitching temperature by the time the starter is ready... Then it gets aerated into the wash... I have yet to have it take longer than 15 minutes for the airlock to kick in and a krausen to start forming...

[MitchyBourbon]

Keep in mind, if you are using dry yeast it is a good idea to rehydrate with plain water.

Dry yeast cells are like sponges. When they are put into a liquid they can't help absorbing everything including dissolved sugar. Imagine if you absorbed a taco through your skin... it would probably kill you.

[jb-texshine]

Imagine if you absorbed a taco through your skin... it would probably kill you.

That's actually how we eat tacos in Texas...

[rager]

i always have used some of the mash that the yeast is going to be pitched into , but i dilute it down to about 1.02 or about 25% of the OG in a 2 quart mason jar. while the started gets going , my mash is cooling. by the time my mash is cool enough to pitch the yeast, the starter is really taken off. then ill pitch the yeast, hit it with the dry wall mixer for 1-2 minutes and get a good vortex in the bucket and let it go. never had a problem .

[waffletalk]

You want to add either compressed sterile air, or oxygen into the cool wort before you pitch yeast. If you have the equipment you are targeting somewhere between 7-12 ppm dissolved oxygen. It is possible to go as high as 30-40 with O2 from a tank, so be careful not to over airete. Compressed oil free sterile air will max out at about 8ppm so you eliminate that risk.

Secret. The amino acid that yeast use the oxygen to create can be given to them in the form of high oleic acid olive oil. If aeration sounds like too much of a pain, you are welcome to try a drop of olive oil per five gallons.

Once the fermentation has taken off, oxygen is the enemy. You want to keep as much oxygen out of the process as possible. Don't open up your fermenter to stir it. Yeast will use oxygen to create more mass instead of more alcohol. Bacteria will take the oxygen and make nasty tasting and smelling things. The wash will absorb the oxygen causing staleing and off flavors, premature aging, and by production of ethanol additional esters such as acetaldehyde will be produced in the presence of additional oxygen.

However, if you are making an exceptionally strong wort ie. 25+ plato/brix it will make sense to add additional oxygen to the ferment between the 6 hour and 12 hour mark of fermentation. Some extremely high alcohol beers, are made with additions of oxygen throughout the fermentation process though most would consider those beers to still be in the research phase.

~J~

[Aussiedownunder01]

I have got a bit slack
In an 80 litre fermenter 1/3 hot water out of the tap 62 deg putting that in I wash out the tom past jar
Then 16 kg sugar stir well then citric acid Epsom salts 1/2 tin of bakers yeast 1 tablespoon ec1118
Then hit it with the pressure hose to fill it and aerate it normally finishes at 30 deg
Starts bubbling in 1/2 hr takes 7 days to finish in summer longer in winter