Rehydrating & pitching dry yeast

[Ladd]

This is the first I have ever heard of re-hydrating dry yeast. Until the last couple of years I brewed nothing but Coopers or John Bull extract beers, had never once re-hydrated the yeast (I just used the yeast that came with them) and have never had any problems in the 15 years or so that I had been making them... I mainly use liquid yeast now but I wouldn't think twice about just pitching dry yeast right onto the wort, unless it was a high gravity beer. Then I would just pitch two packets.

[derek]

This is the first I have ever heard of re-hydrating dry yeast. Until the last couple of years I brewed nothing but Coopers or John Bull extract beers, had never once re-hydrated the yeast (I just used the yeast that came with them) and have never had any problems in the 15 years or so that I had been making them... I mainly use liquid yeast now but I wouldn't think twice about just pitching dry yeast right onto the wort, unless it was a high gravity beer. Then I would just pitch two packets.

Rehydrating has always been recommended, though I notice the Safale packs just say "sprinkle on wort". All Lallemand packs show you how to rehydrate. otoh, I've never boiled the water I use to rehydrate, and why on earth would you need to measure it?

Frankly, if you use the yeast that came with a Coopers or John Bull extract, I don't know how you'd tell if you had a problem.

[GuingesRock]

This is the first I have ever heard of re-hydrating dry yeast. Until the last couple of years I brewed nothing but Coopers or John Bull extract beers, had never once re-hydrated the yeast (I just used the yeast that came with them) and have never had any problems in the 15 years or so that I had been making them... I mainly use liquid yeast now but I wouldn't think twice about just pitching dry yeast right onto the wort, unless it was a high gravity beer. Then I would just pitch two packets.

Rehydrating has always been recommended, though I notice the Safale packs just say "sprinkle on wort". All Lallemand packs show you how to rehydrate. otoh, I've never boiled the water I use to rehydrate, and why on earth would you need to measure it?

Frankly, if you use the yeast that came with a Coopers or John Bull extract, I don't know how you'd tell if you had a problem.

This debate is heating up nicely

Was it Gulliver’s Travels or the sequel, where the “Big Endians” were always at war with the “Little Endians” over which end you should open your boiled eggs.

I'm betting the yeast was the best ingredient in those kits

[Ladd]

I don't think anyone is going to disagree that those kits are crap. I hope you picked up on the tense that I wrote that in! I didn't know any different until I discovered Festa Brew. A few batches of those later and I was into all grain and haven't looked back. Best choice I ever made!

The point I was trying to make was that I had never heard of re-hydrating dry yeast right up until this thread was posted and of the many, many extract kits I have made, I never had a problem with fermentation taking off. I had never done it and nowhere in the instructions of any kit I have ever had mentioned doing it either. It was always "sprinkle on top of the wort" so that's what I always did.

[CartoonCod]

Sure non rehydrated yeast will work fine and you can get good beer from it, but the real question is, does it make better beer if you rehydrate first? Rehydrating should increase the viability of yeast cells if done properly which means you are pitching less dead cells into your beer. If you've already got way more yeast than you need for a healthy fermentation and the beer is not left too long on the yeast cake then even if some proportion of them are dead it shouldn't matter because there are still enough to get the job done. I suspect in situations like this it does not matter one way or the other. It probably does matter if you need more healthy yeast and are looking for a specific fermentation character.

[GuingesRock]

Nice post Adam. I think there are answers to be found here, and the discussions are along the lines of your comment, final conclusion though…not really worth it:

I don't think anyone is going to disagree that those kits are crap. I hope you picked up on the tense that I wrote that in!

Was it really that bad? I never tried it, but it has to be better than Coors or Keiths? My brother-in-law said he used to make it (Coopers I think) and he said people loved it. Also the ingredients might be a bit better than American mega-swill which is 40% rice that's cereal mashed, and all the yeast flavours, and other flavours are probably filtered out.

[CartoonCod]

Thanks for the article, it was very interesting. I would have preferred a bit more a focus on taste as the qualifier, but apparent attenuation seems like a relevant quantitative measure. Another issue I had with the article is the lack of replication, but since most of the results were quite close together this is probably not a big problem. But, they did more than I have the energy to do. Maybe I'll try not rehydrating my yeast next time and see what happens.

[GuingesRock]

I should probably try rehydrating some time as well, and get some experience of that also. I like X’s idea of the erlenmeyer flask. I would boil the water in that on the stove. They have volume measures too. I wish there were such a thing as one of those flasks with an integral thermometer to make things simple. I wonder if those stick on thermometer strips withstand boiling temperatures? I know they don't measure that high but interested to know if they get damaged by high temperatures. Rob, do you cover the flask with anything?

Could you fill such a thing with boiling water from the kettle, let it sit for a while to sanitise and then pour out the excess water?

[mr x]

I use a small beaker to cover. I think the kettle method would work.

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[AllanMar]

I use an infrared thermometer for checking the temp (without placing anything in the flask). Its within a degree or two of a thermometer temp when I've checked it.

I got a really cheap one of ebay not long ago, not as good as the pricey ones we have at work, but defiantly good enough for me.

[GuingesRock]

Will it check temperature through the glass/of the glass?

[mr x]

Should.

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[LeafMan66_67]

Did an experiment one - one probe in carboy, one probe against the glass of the carboy. Both temps read within a 10th of a degree.

[GuingesRock]

Based on information from Adam and Rob, I came up with a contraption for re-hydrating dry yeast.

The stick on thermometer tape does survive boiling temperatures but they only go up to 30C which isn’t quite high enough. Both the stuck on digital thermometer and the tape correlated surprisingly well with my thermapen which was dipped into the water in the flask. The stuck on thermometer was within ½ F of the thermapen which I thought was pretty amazing. The green tape at the bottom is supposed to insulate the tip a little on the outside. Thermometer, was about $17 from home hardware.


I filled the flask to the brim with boiling and filtered water from the kettle and put the shot glass on top. I’ll leave it to cool and when I am ready to add the dried yeast I will pour out excess water down to the mark on the flask. Final temperature adjustments will be by water bath.

[adams81]

I rehydrate with unboiled tap water.

This thread is intense.

[GuingesRock]

I rehydrate with unboiled tap water.

This thread is intense.

Thanks for the reality check. Getting carried away I know…I blame it on the beer.

Maybe I’ll go back to sprinkling when I’ve sobered up a bit.

[AllanMar]

I'm a believer in rehydrating (without firm reason why), but I usually just use unboiled water as well.

The IR therm I used is this: http://www.hbfca.com/2013/08/non-contac ... r-cdn.html" onclick="window.open(this.href);return false;
The only problem Ive had with it is while on the stove (gas stove) as it often picks up the heat of the burner based on where I put it. I should run some more tests to see how accurate it is, but I did it once or twice and it was good enough that I dont worry about it anymore.

Its pretty ghetto, but as I said worked pretty good compared to the expensive fluke ones Ive used. I ordered it with a $9 digital Ph meter also mentioned on that site (haven't been able to compare that to my Hanna meter yet)

[GuingesRock]

I actually liked it (re-hydrating). I rehydrated for 20 mins at 34C > 32C, and at the end I had 400mls of milky liquid to pour in the wort. With my system of having a brew kettle with a built in immersion chiller that becomes the primary fermentor (with built in fermentation temperature control using the immersion chiller), I didn’t need to attemperate the rehydrated yeast at 5min intervals until it reached within 8C of the wort temperature to avoid cold shock…instead I pitched it directly when the wort was at 30C and let it slowly hitch a ride with the wort down to 20C.

[GuingesRock]

I got some Mangrove Jack M44 yeast and decided to give it some loving by re-hydrating it and putting a drop of olive oil and some wyeast nutrients into the end of the boil (10 mins before end of boil).

I found a cheap hotplate at home hardware and it actually has a thermostat on it rather than a heat output control. I've calibrated it to keep the water in the flask at 30C ready for when I need to rehydrate. I boil first on the hotplate to sanitize, then turn the thermostat down to my mark that I made. 1 - 2 hours later it is at the correct temp for re-hydrating. 10 mins or so after adding the dry yeast, I will turn the hot plate off to let it cool down a bit for 10 - 15 mins to approach the temp of the wort before pitching.

[GAM]

I rip open the packet with my teeth and show it to the wert. Hasen't failed me yet!!!!!!!!!

I have rehydrated but didn't find it ade a difference. I just rip and pour.

Sandy

[GuingesRock]

I usually just chuck it in too, but this is my special yeast It's supposed to be "dried Pacman"

[dean2k]

I rip open the packet with my teeth and show it to the wert.

I nominate this quote as post of the year

[mr x]

Lol

[GuingesRock]

I got some Mangrove Jack M44 yeast and decided to give it some loving by re-hydrating it and putting a drop of olive oil and some wyeast nutrients into the end of the boil (10 mins before end of boil).

I lifted the lid of my boiling/fermenting contraption and there is no froth on the top. It's been 20 hours since I pitched it. I haven't used this yeast before. I'm getting worried. Contemplating throwing in some 05 as per Sandy's instructions. Should I hold off a bit longer? Any yeast I have used so far has been well underway by now.

It has been heating up though and I've run the coiling coil a couple of times to bring it under 70F but I don't know if it's because the room is warm. I usually expect to see active krausen on the surface by now.

I'm stressed.

[jason.loxton]

Here's a graph that shows why rehydrating--and temperature--matter. Total cell count not only is relevant to ester production, etc., but also, perhaps more importantly, to lag time, which effects the ability of 'bad guys' to get a foothold in your beer.

yeast.jpg

From here: http://bkyeast.wordpress.com/2013/03/13 ... hydration/" onclick="window.open(this.href);return false;