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Temperature of wort for pitching yeast

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The instructions that Mr Beer provides for perparing a wort don't suggest (as far as I can see) that you may need to cool the wort or otherwise wait before pitching the yeast. I just started a batch of the limited edition 2013 saison that was offered recently for a discount. The temperature in the keg is about 100F and I think that that is a little too high for the yeast but there is no advice or warning in the instructions that suggest that you might need to chill or cool the wort prior to pitching the yeast...

  1. Using the measuring cup, pour 4 cups of water into your clean 3-quart or larger pot. Bring water to a boil, and then remove from heat. Open the can of HMEb and pour it into the hot water. Stir until thoroughly mixed. This mixture of unfermented beer is called wort.
  2. Fill keg with cold tap water to the 4-quart mark on the back.c
  3. Pour the wort into the keg, and then bring the volume of the keg to the 8.5-quart mark by adding more cold water. Stir vigorously with the spoon or whisk. d
  4. Sprinkle the yeast packet into the keg, and screw on the lid. Do not stir.
  5. Put your keg in a location with a consistent temperature between 63°and 75° F (17°-24° C) and out of direct sunlight.e Ferment for 14 days.f

 

True, I may have been a little more generous in boiling closer to 4 qts of water than the 1 qt (4 cups) in the instructions... but shouldn't the instructuions make clear that pitching the yeast when the temperature of the wort is higher than about 70 degrees is not good for the yeast... ? Just askin'

Thoughts?

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There is no reason to boil 4 quarts of water, that's your issue. If you do 1 quart as the instructions tell you to, mixed with a gallon of cold water per the directions, then topped off with cold water, you would have no temperature issues.

If you boil a gallon, you would need to lower it to 100 BEFORE adding it to a gallon of refrigerated water in the LBK, to end in the 60s. Then add refrigerated water to top off.

 

Since people don't have thermometers, by specifying temps Mr. Beer would just complicate things.

 

I regularly make 5 gallon batches split between 2 LBKs.  I put 2.5 gallons of water in the pot, and add LME and hops, boiling for an hour.  I end up with 2.5 gallons or so of liquid left.  I cool this liquid to 100 degrees.  I split it between two LBKs with a gallon of refrigerated water in each, then top off with refrigerated water.  The end result is around 60 - 62 degrees.  As I said, this isn't necessary to do if you brew a Mr. Beer batch and follow the directions.
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MrB is designed for beginners who will follow the instructions to the letter scared they'll screw up the brew.  When you go out side the box we try to help.

 

Fwiw it's not just the heat. it's the environment as well. When you re-hydrate yeast the temps, which vary from strain to strain, range from as low as 96f to as high as 105f, but it's water, nothing to feed on. Weird as it sounds and as near as I could understand it. It's the sugar and heat that's stresses the yeasts, they're trying to feed too soon.

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Following the  recipe (4 cups water), my wort for Saison came in correct range for pitching - I have the Saison now fermenting happily. :-D

If you overdo the water it will be too hot but np if you wait for it to cool a bit. This is a good reason to have a stick-on temp indicator on the vessel. (even the "low-check_mark-high" version works.)

 

This could also be an concern for very strong beers where the malt content is very heavy, that will increase heat energy transferred to the wort also.

 

Also note that cold fermenting lager yeast (e.g. Fermentis) recommend (on the packet) pitching at 70 deg+ and waiting until the yeast gets going before you take it to the 50's.

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I guess my question was whether it might not be a good idea for the instructions to advise folk that the temperature for pitching the yeast is fairly critical but if the idea is that custormers always follow the instructions to a "T" and they never make a mistake and their pitching temperature is always within specs for good rehydration of the yeast then adding that piece of information may make brewing seem more complicated and confusing and so it is better to avoid information than provide it... ;) ...

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A few comments here:  

 

Yeast is very temperature sensitive.  If you don't properly pitch at the proper temp, you risk off flavors.  In my opinion, this is one of the most common screw ups with new brewers.  Mr. Beer doesn't get specific here simply to keep it simple.  However, if you are branching out into different yeast strains or advanced recipes, you absolutely must have a calibrated thermometer to ensure proper pitching temps.  If you pitch too hot, you will get off flavors.  If you pitch too low, the yeast may not reproduce enough to properly attenuate the wort.  

 

I always advise pitching at the recommended fermentation range or lower.  I prefer to use a pitching calc to determine the proper pitching rate, either do a starter or rehydrate the dry yeast, and pitch about 2-3 degrees below the ferment temp.  The yeast will naturally warm up the wort when they are working, and this ensure a slower spike in temp.  If you pitch too hot, and the wort cools down, you risk a stalled fermentation with some yeasts that don't like to start warm and cool off.  

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I guess my question was whether it might not be a good idea for the instructions to advise folk that the temperature for pitching the yeast is fairly critical but if the idea is that custormers always follow the instructions to a "T" and they never make a mistake and their pitching temperature is always within specs for good rehydration of the yeast then adding that piece of information may make brewing seem more complicated and confusing and so it is better to avoid information than provide it... ;) ...

 

I think they are just trying to keep it simple.  I do agree there will be some that don't follow the instructions perfectly that are set up for issues with temps.  

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To my knowledge, pitching temperature has more to do with the initial hydration of the yeast and how many actually survive, rather than creating off flavors. The "off" flavors arise from too high a fermentation temperature. Rehydrating into plain warm water, creates less osmotic "stress" for the yeast. Somewhere between 90-105 deg f is typical. Mr Beer has the brewer just sprinkle the yeast into the cooled wart - probably not the best osmotic conditions fro the yeast to regain water. However, enough yeast survive to ferment the wort and that is all that matters to a novice. 

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Brewer, on 15 Feb 2015 - 12:03 PM, said:

I guess my question was whether it might not be a good idea for the instructions to advise folk that the temperature for pitching the yeast is fairly critical but if the idea is that custormers always follow the instructions to a "T" and they never make a mistake and their pitching temperature is always within specs for good rehydration of the yeast then adding that piece of information may make brewing seem more complicated and confusing and so it is better to avoid information than provide it... ;) ...

 Well not that they never make mistakes, but you got to admit 4 cups/4 quarts...that's a pretty big boo boo. Not one you'd expect a noob , who are (believe me) if anything overly attentive to details, to make. They are usually like: Oh gosh my wife looked at my lbk, is it ruined?  You want to explore brewing, great, read first prevents a lot of mistakes. Here's a good place to start and it's free. (big + for me)  http://howtobrew.com/

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I guess my question was whether it might not be a good idea for the instructions to advise folk that the temperature for pitching the yeast is fairly critical but if the idea is that custormers always follow the instructions to a "T" and they never make a mistake and their pitching temperature is always within specs for good rehydration of the yeast then adding that piece of information may make brewing seem more complicated and confusing and so it is better to avoid information than provide it... ;) ...

Don't need to include added steps if you follow the directions.

 

I understand you might want to know why you do each step.  But if you follow them precisely, you don't NEED to know.  But you can ask later on.

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Well, they could make the basic instructions so overly complicated that it is even worse for a beginner.  However, if one actually follows the direction and only boils 4 cups of water, and uses cold water to absorb the impact and to top it off, it will be in the correct pitching temperature.  I think for the intended audience, the instructions are perfect.

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To my knowledge, pitching temperature has more to do with the initial hydration of the yeast and how many actually survive, rather than creating off flavors. The "off" flavors arise from too high a fermentation temperature. Rehydrating into plain warm water, creates less osmotic "stress" for the yeast. Somewhere between 90-105 deg f is typical. Mr Beer has the brewer just sprinkle the yeast into the cooled wart - probably not the best osmotic conditions fro the yeast to regain water. However, enough yeast survive to ferment the wort and that is all that matters to a novice. 

 

I guarantee that off flavors will be generated if you pitch into wort that is too warm.  The yeast will be stressed, and the generation of fusel alcohols will ensue.  The large volume of wort will not cool to proper temp for at least a few hours, in which time the yeast has been propagating.  If the environment for propagation is too warm, off flavors happen.  Re hydrating is totally different than pitching into wort that is too warm.  

 

For more information, I recommend the Yeast book in the brewing elements series.  

 

Long story short, pitch at proper temps.  

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I guess my question was whether it might not be a good idea for the instructions to advise folk that the temperature for pitching the yeast is fairly critical but if the idea is that custormers always follow the instructions to a "T" and they never make a mistake and their pitching temperature is always within specs for good rehydration of the yeast then adding that piece of information may make brewing seem more complicated and confusing and so it is better to avoid information than provide it... ;) ...

Yes, that's a bit of a catch 22. I see the the conflict between trying to avoid making it too complicated for a beginner and providing more details. Phrases like "need to know basis" and "milk before meat" come to mind. All that aside, Brewer, I think you have hit on an excellent suggestion for Mr Beer to amend, or should I say improve, or even perfect, the instructions. I think the little insertion at that point to include the expected or even critical temp of wort to pitch yeast into would be a very wise move. Nothing to lose and all to gain. I refer to Murphy's law. I give your suggestion two thumbs up.
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It's already been said more than once in this thread, but I'm going to go ahead and say it again: If you follow the instructions, there is no need to worry about pitching temps.

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I make a lot of frozen food for lunch and such.  Almost all of them have microwave instructions.  They say to cook on high/medium/etc for X amount of time.  Could it say on there that cooking longer than recommended result in burnt food?  Sure.  But does it? Nope.  Why?  Because they told you how to do it without burning your food.  And if you burn the food, then you weren't following the instructions.

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