Red Star distillers yeast heat tolerance?

[DWelsh]

I started an uncooked sour mash and I'm on the second fermentation using Red Star Dady distillers yeast. I made a second yeast starter and rehydrated at 85F like Ive always done. The mash was around 79 F when I pitched the yeast and fermentation was doing great based on the airlock. On the second day the temp of the mash fell to around 75 so I put the carboy in a closet with a space heater for a while but then forgot about it for around 2 hours. The thermometer sticker on the carboy said 97F which is as high as it goes, and the sides of the bucket felt like they could have been slighly higher. I've never thought about it, but can this yeast handle temperatures around 100F if they are very gradually brought up to this temperature range? Should I throw away and start over? I am really hoping that someone who actually knows alot about this type of yeast can give me advice, thanks.

[shadylane]

It might be making unwanted flavors but bakers yeast can survive 100f easily.
One thing bakers yeast doesn't like, is high temp near the end, when it's swimming in 10% or more of alcohol.

[BoomTown]

yeast is temperature sincetive for sure. We try to maintain a 'warm room' reading of around 80F ambient temp during the entire fermenting cycle. A steady temperature allows for reproducing the same taste chracterisitics between batches.

TIP: Be sure to set your fermenting batches on an insulation if you are using flat bottom buckets. the Cold of the floor can draw the overall temp down pretty dramatically. This can even lead to a stall it ti drops below 70f.

Your yeast will survive up to about 110F, but the results may not be optimum for what ever you are trying to make.

So say I

[shadylane]

Dang, just realized he ask about Red Star ---Distillers ---yeast.

[still_stirrin]

According to Fermentis, the maximum ferment temperature should be 90*F, or less. Deviations will produce ferment by-products that may be undesirable.

DADY Distillers Active Dry Yeast (Saccharomyces cerevisiae)

A specially selected strain of Saccharomyces Cerevisae designed for distillers use in grain mash fermentations for ethanol. DADY will produce maximum alcohol yields under controlled temperatures (86-89*F / 30-32*C).
It has been the choice of many producers in North America for over 20 years. It has been used for the manufacture of light spirit and Whiskeys. It is also used on corn mash and syrup fermentations.

Re-hydrate in a stirred vessel prior to pitching. Sprinkle the dry yeast into 10 times its own weight of water or wort at 35C ± 3C (80F ± 6F). When the yeast is reconstituted into a cream (15 to 30 mins), continue to stir for another 30 minutes. The yeast cream is then ready to pitch into the fermentation vessel.

Please note that any change to a fermentation process may alter the final product quality. We therefore advise that fermentation trials are carried out prior to using our yeast commercially.