Correct Yeast Pitch Temp

[djschererjr]

I know I am not the first to ask this question or to ask for some nuances regarding it, but general question: what is the "proper" yeast pitching temperature?

I brewed my 4th batch on Saturday (Oatmeal Stout) from a MWS LME kit. The instructions called for the wort to be cooled below 80 degF before pitching yeast. The kit came with Safale S-04 Whitbred Strain Dry Yeast (59 degF - 72 degF).

I rehydrated the yeast in 1 cup of 90 degF preboiled water and let sit for at least 30 mins. At flame out, I started running water through the wort chiller and got down to below 80 degF. However, after aerating, I checked the temp again (1st time in 4 batches doing this) and it was at 100 degF. I had not (and have not) been stirring the wort during the chill. Learning experience I presume.

Anyway, I placed the wort in my primary (bucket) and set in my freezer with external temp control. I place the RTD underneath a thawed ice pack bag which is strapped to the side of the bucket. When the temp at the sensor hit 78 degF, I pitched my hydrated yeast.

I'll take another gravity reading in a few days, but what mistakes did I make?

Also, despite the "below 80 degF", should I generally have pitched this yeast at 75 or less?

Lastly, given my learning on the "thought to be chilled wort temp", i.e. stirring the wort during chill, the fact that I've done three other batches (different styles) the same way and the fact that all seemed to have the same "hot" aftertaste, I am hoping for an improvement here in this one.

Thanks

 

[jekeane]

In general pitching the yeast as close to fermenting temperature as possible is good practice. I like to pitch 2°F colder than the temp I set for fermentation and let the yeast bring the wort up to temperature. I also tend to ferment on the cold side of a yeast range. There are exceptions to this of course but in general I think it is a practice that has worked well for me.

The yeast are working and producing almost immediately after being place into your wort. If the yeast starts working at a temp outside of its range or outside of the range you want you may / will likely see flavors change based on the starting temperatures. Instructions for pitching below 80° if using temperature control is probably fine. But for people who can't get their wort down to temperature soon after pitching those directions set them up for bad beer imo.

 

[Showdown]

If I'm reading this right, your first pitch was in 90* water to rehydrate. This might kill your yeast before you even pitched it in the fermenter.

 

[1977Brewer]

If I'm reading this right, your first pitch was in 90* water to rehydrate. This might kill your yeast before you even pitched it in the fermenter.

90* water will not kill yeast. In fact they'll love it so much they have an ester party.

 

[pablosbrewing]

If I'm reading this right, your first pitch was in 90* water to rehydrate. This might kill your yeast before you even pitched it in the fermenter.

Not too hot, in fact may be slightly cooler than optimal for some. Read the manufacturer's instructions.

If those don't give a rehydration temperature, I'd follow Chris White and Jamil Zainasheff's advice from their book Yeast:

Every yeast strain has its own optimum rehydration process, but the basic process is as follows:
1. Warm the dry yeast to room temperature.
2. In a sanitized container, prepare an amount of sterile tap water at 105° F (41° C) equal to 10 times the weight of the yeast (10 ml/g of yeast).
3. Sprinkle the dry yeast on top of the water, trying to avoid setting up large, dry clumps. Let sit 15 minutes, then gently stir.
4. Once the yeast has reconstituted, gently stir once again to form a cream, and let sit another 5 minutes.
5. Carefully and slowly, adjust the temperature of the yeast to within 15° F (8° C) of the wort temperature.
6. Pitch the resultant cream into the fermentation vessel, ideally as soon as possible.

Chris White (2010-01-03T08:00:00+00:00). Yeast (Kindle Locations 2421-2429). Brewers Association. Kindle Edition.

 

[Natdavis777]

I, too, ferment on the cooler side so I like to pitch around 60F and slowly increase the temp as fermentation progresses.

 

[djschererjr]

Thanks for the replies.

Got the very basics of the process down. Beer has been drinkable, but not something I'd want to show off. Being more particular about temp will be something I need to stress moving forward. I'll certainly have to take more care on the rehydration. At some point, I want to move to liquid yeast/starters, but I am not there yet.

Palmer instructs to pitch the rehydrated yeast into the fermenter and then pour in the wort aggressively to aerate. Other instructions (the one with this kit, Brewer's Friend) instruct to aerate into the fermenter and then pitch. Which is correct? Both?

Lastly, where in the process do you begin the rehydration with respect to the boil, wort chill, etc.? Just looking for what others do to see how I might coordinate these steps better in the future.

 

[chewse]

Just my opinion.....After you rehydrate your yeast based on the dry yeast instructions and let is sit for at least 15 minutes, check the temp of the yeast. If that temp let's say is 80 degrees and your wort temp has cooled down to approximately the same temp, then pitch it. You can then slowly cool down to wort with the pitched yeast in it to the optimal temp; i.e., 67 degrees. Generally, you try not to shock the yeast too much.

 

[BigFloyd]

Correct pitch temp is at or a few degrees cooler than your initial target fermentation temp. For most commonly used ale yeasts, that's in the 60-62*F range. For lagers, I'll take it down to 45*F. IMO, pitching into 80*F wort is asking for off-flavors.

When rehydrating dry yeast, I boil some tap water in a measuring cup in the microwave, cover with sanitized foil and let it sit on the counter while boiling the wort, shooting for 100*F +/-5*F water in which to sprinkle the yeast. After the yeast has had a chance to rehydrate, "attemperate" it by adding a small amount of chilled wort, stirring and letting it it a few minutes. After a few times of doing this, the yeast slurry should be within 10*F of the wort and is OK to pitch.

 

[stpug]

After years of "pitching a little cooler and letting it warm up" I've taken the opposite approach of "pitching a little warmer and cooling it down", and I have personally been enjoying the results. Caveat: I use a temperature controlled fermentation chamber so adjusting to a specific temperature after chiller is easy.

I'd be hard-pressed to say there's been any noticeable taste/aroma difference in the beers I've been producing this way. If I was forced to say one way or another, I would say they have been better in that regard.

Other benefits have been:
-Less time cooling wort to pitching temp
-Wasting less water during cooling process
-Shorter lag time (the initial, warmer environment helps the yeast get moving a little quicker)
-Shorter brewday overall
-Less attemperating rehydrated yeast because delta is much smaller

With my tapwater, I would say the savings on cooling is significant because for ales I can pretty quickly get to ~70F from boiling (~12 minutes), but for me to go from 70 to 60F with my chiller it can take an additional 10 or more minutes depending on how cold my groundwater is.

Worse yet are lagers where I'm aiming for ~50F - I can't even get there in the summer time using my chiller. I've ended up going the route of: cool to 70F (10minutes); into chamber set to 50F; pitch when I hit 50F. The 20F drop in the chamber only takes a couple hours and saves a HUGE amount of water and time. Plus it's a "set it / forget it" situation while I carry on with my other duties (work, cleaning, etc).

At least, that's my take on it!