Question about statement Beechum's Everything Homebrewing Book

[bernardsmith]

Got a copy of the Beechum book and think that it is incredibly confusingly written- not least because if it assumes that the reader has never brewed a batch then his chapters and recipes and appendices assume a far more experienced brewer... but be that as it may.
On page 61 Beechum discusses dehydrating dried yeast. He recommends that you pitch dried yeast into water that you have boiled and allowed to cool to "around 100 F". If rehydrating temperatures are to be "around" 100F (suggesting that even a few degrees hotter is fine...) then why all the concern about getting the wort to get to way below 90 (Beechum never provides a temperature for pitching the yeast - only that you need to get the wort to about 90 and then add a quantity (several gallons of chilled water to get to the volume of your batch)... Why can rehydration be at around 100 while pitching yeast should take place at around 65 -70?

 

[unionrdr]

I like to rehydrate dry yeast at 80-90F. Sprinkle it on the water & cover with sanitized plastic or foil. Let sit 15 minutes. Then stir with something sanitized, recover & wait another 15 minutes or so. Stir & pitch yeast withing 10 degrees of current wort temp for a healthy pitch that doesn't shock the yeast.

 

[chickypad]

If the yeast starts fermenting the wort too hot you can get off flavors like fusel alcohols, inappropriate esters, etc. Also pitching hot then cooling may cause the yeast to stall or drop out. In general it's best to pitch at the low end of the yeast's temp range then let it rise a bit at the end - helps the yeast finish up and you won't get nasty off flavors that way.

 

[Peyope]

I don't know the scientific answer to this. What I do know is that rehydrating yeast is not the same as making beer in that you're not giving the yeast a source of food. It's my understanding that when yeast are pitched at higher temps they will still ferment but will create off flavors. When you rehydrate yeast you are not fermenting anything.

 

[flars]

You can rehydrate yeast at 100°F, but there is no sound reason to. Danstar and Fermentis recommend 95° to 77°.
Most ale yeasts ferment best in the low to mid 60°F range. When you pitch yeast into a wort that is 10° or greater in temperature, and then chill the wort to fermentation temperature, it is a shock to the yeast. The yeast that begins the fermentation at this high temperature may never recover from the shock or may throw off flavors into the wort.
It is also much harder to cool an active fermentation than it is to pitch the yeast below fermentation temperature, and let the wort warm to fermentation temperature.

You are right, it doesn't make sense. More of a case of repeating the old way of doing things.

There is one certain thing about books. Some of the data may be out of date as soon as the book is published.

 

[brick_haus]

I'm going to see him (Beechum) today. I'll ask him for his explaination.

 

[bernardsmith]

I'm going to see him (Beechum) today. I'll ask him for his explaination.

Thank you. I am sure that Beechum is a good bloke but for the record, I thought his book on cider making was written for the audience he seemed to be aiming at. I thought his book on brewing was not..It's kinda half baked... . You cannot expect a novice (IMO) to make sense of a recipe when all the key information other than ingredients is buried 200 odd pages away in an appendix and you cannot expect a complete novice to start with wheat beer recipes that uses two half ounce quantities of hops, and two quarter ounce measures of hops ... and quantities of LME that I don't think are sold as batches (with no word to the beginner as to how she or he may need to store excess liquid malt). What's the rationale for starting a novice with mildly complex recipes rather than with simple off the shelf ingredients

 

[Beernik]

Like said above, it's a difference between waking the yeast up and having the yeast reproduce and ferment.

You don't want to rehydrate above 100F because you risk killing your yeast. As long as you are below that, temperature is not too critical.

When you pitch your yeast, it goes into a phase of rapid reproduction as it begins to ferment your wort and most off flavor compounds are generated early in the fermentation. If the wort is too hot, the yeast will throw a lot of off flavors: phenols, esters, acetaldehyde, diacetyl, etc.

If you have good fermentation temperature control, you can pitch your yeast a little warmer than the desired fermentation and let your ferm chamber bring the temperature of the wort the rest of the way down (as long as it happens reasonably quickly) and not experience any ill effects.

If you don't have good fermentation temperature control, you want to cool your wort a little below the desired fermentation temperature and let the yeast's fermentation bring the wort temperature up to the desired fermentation temperature.

 

[progmac]

100f is fine. It's a fine recommendation. There is nothing to explain. There is some actual science to refer to that supports this.

 

[Beernik]

I looked at the LME numbers. The ones that aren't multiples of 3.3 are recipes that were made for AG and back calculated to LME equivalents.

The problem with LME is that you can't store an opened container very well. Once you open it, it starts to degrade and go stale. DME stores extremely well as long as it's dry. I like to double ziplock bag it and keep it in a freezer.

I would do one of two things:
1) convert all the LME to DME. 0.8lb DME = 1lb LME. So 12lb of LME = 9.6lb of DME.
2) use the 3.3lb multiple of LME and make up the rest with DME. So 12lbs of LME = 9.9lb of LME + 1.68lb of DME.

 

[brick_haus]

Spoke to Drew today at our club meeting. His take on this is that ~100*F is OK for water temp when rehydrating ( obviously, it's in his book).
And he adds that pitching(the yeast not the wort temp) at that same temp will not affect the performance of the yeast.
To paraphrase, yeast are hearty animals and they will be OK. No ill effects from the sudden drop in temp...

 

[TimmyWit]

From the Yeast book on page 147, they state to rehydrate in water between 95 and 105 with the following explanation:

"Warmth is critical to the cell during the first moments of reconstituting it's fragile cell membrane. Lower temperatures result in more cell material leaching out of the cell during rehydration, which permanently damages the cell. At the optimum temperature, it is possible to recover 100% of the cells. Too cold a temperature can result in the death of more than 50% of the population."

 

[chickypad]

From the Yeast book on page 147, they state to rehydrate in water between 95 and 105 with the following explanation:

"Warmth is critical to the cell during the first moments of reconstituting it's fragile cell membrane. Lower temperatures result in more cell material leaching out of the cell during rehydration, which permanently damages the cell. At the optimum temperature, it is possible to recover 100% of the cells. Too cold a temperature can result in the death of more than 50% of the population."

Also mentions on that same page as well as in the Danstar instructions that temp shock in the 8-10*C range (15-18*F) can lead to formation of petite mutants. They both recommend you attemperate wtih small amounts of wort before pitching.

 

[brick_haus]

Dont know what a petite mutant is, but regardless of what Grand Hydrometer Drew says (not saying that he is wrong) , I always attemperate. It takes about 20 seconds and its free!
On the other hand, if you introduce your dry yeast to 100* water, by the time the rehydration is complete, ~ 20-30 minutes, it is normally within the 15-18*F tolerance range to prevent the formations of petite mutants. Weather dependent!!!

 

[bernardsmith]

I looked at the LME numbers. The ones that aren't multiples of 3.3 are recipes that were made for AG and back calculated to LME equivalents.

The problem with LME is that you can't store an opened container very well. Once you open it, it starts to degrade and go stale. DME stores extremely well as long as it's dry. I like to double ziplock bag it and keep it in a freezer.

I would do one of two things:
1) convert all the LME to DME. 0.8lb DME = 1lb LME. So 12lb of LME = 9.6lb of DME.
2) use the 3.3lb multiple of LME and make up the rest with DME. So 12lbs of LME = 9.9lb of LME + 1.68lb of DME.

Thanks Beernik. I actually brew all grain. My point was not how one might convert the recipes Beechum uses but that his recipes - supposedly written for the rank beginner are far less "simple" than they might appear and he (or his editor) seem to ignore the very (to me) obvious questions that anyone trying to brew for the first time and using his book must have...