Double pitching dry yeast? Overpitching problems?

I am gearing up for a couple of 1.050 range brews this weekend and will not be making starters for the dry yeast (safale-05)
Has anyone here had problems pitching two packs in a 6 gallon batch? If so, what were they?
MrMalty has a 6 gallon batch at 1.050 as requiring exactly one 11.5 gram pack of yeast.
I am considering pitching more out of pure curiosity and to see what kind of results i get out of using the additional yeast, but would like to hear your results if you have tried it.
Thanks

I haven't specifically tried pitching two packets at once (at least not in beers that didn't need it), but here are some things to keep in mind. Yeast growth is sensitive to inoculation rate. If the inoculation rate goes up, the yield factor goes down. Beer flavors are affected by yeast growth factor.

My biggest concern would be that more yeast will generate more heat, which will bump up your fermentation temps. With proper fermentation control, that's not an issue, but that could push your beer too hot and give you some harsh/solvent flavors if unchecked.

I think, off the top of my head, overpitching gets you decreased ester and increased acetylaldehyde formation.

And can also result in a thinner, more highly attenuated beer.

Lando said:

I am gearing up for a couple of 1.050 range brews this weekend and will not be making starters for the dry yeast (safale-05)
Has anyone here had problems pitching two packs in a 6 gallon batch? If so, what were they?
MrMalty has a 6 gallon batch at 1.050 as requiring exactly one 11.5 gram pack of yeast.
I am considering pitching more out of pure curiosity and to see what kind of results i get out of using the additional yeast, but would like to hear your results if you have tried it.
Thanks

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Unless you are paying too much for dry yeast, making a starter costs more than pitching a second pack. That said, I have used single packs of S-04, US-05, Nottingham and Windsor for beers up to an OG of 1.065 with great results. The only beer I have pitched 2 packs (US-05) was a Barley Wine (4.5 gal. @ OG - 1.092.

Lag times have ranged from 8 to 24 hours for the most part, Nottingham being the exception when they were having their problems, and fermentation has always been vigorous.

Proper re-hydration is a must for good results when using dry yeast. Go to the web site of the manufacturer and follow their directions exactly.

As far as over pitching, the only time I have over pitched, according to Mr. Malty, was racking onto a yeast cake, I found no problem with the beer, but the fermentation was so wild that I learned why many brewers use a blow off rather than an air lock.

If Mr. Malty errs at all, it is likely on the side of over pitching. For a 1.050 beer, I would definitely go with 1 packet.

Bob

Not too worried about the temps since I plan to use a temp controlled keezer as soon as my controller arrives.
The acetylaldehyde is a big concern though. Not too worried about the lack or esters.

It's a waste of yeast. Only time I did it I wound up with a heavy alcohol taste which did fade over time, it was a 1.060 ish beer. Mr. M is conservative on the dry yeast numbers in my experience.

When Mr. Malty says 11.5g, he is assuming that you are properly rehydrating those 11.5g. Pitching dry into 60/70F wort cuts the rate of viability by almost 50%, so if you don't rehydrate first, you are kind of throwing the pitching rate stuff out the window.

BBR did a good dry yeast experiement (I think with the help of Sean Terrill), comparing different handling methods of dry yeast into a typical wort. IIRC, Sean used two scenarios that might interest the OP. The first was pitching 1 pack of rehydrated yeast, the second was 2 packs pitched dry. Even though the number of viable cells was almost the exact same, Sean found the flavor of the 2 pack dry pitch to be less stellar, and I believe it was attributed to the huge quanity of dead yeast in the beer.

(It has been a while since I listened, but I am pretty sure that was how things shook out).

OP, are you concerned that you have under-pitched with your techniques with only one yeast pack?

Or are you just curious about the effects on your beer if you were to over-pitch?

I brew 10 gallon batches.

At the 1.050 range, I'll typically use two dry packs [sometimes 3]. When the gravity gets much above that (1.060 or above), I'll usually up it to three packs. If I'm making a high-grav beer (like 1.080 or above), only then will I hit a pitch rate of 4 packs in 10 gallons.

I have been accused of overpitching. But I typically try to pitch cold (a few degrees below target fermentation temp, so often in the high 50's), which I believe can somewhat retard the growth phase of the yeast. So a higher pitch rate doesn't bother me there.

I haven't had any issues from my high pitch rates, and in many cases (a 1.050 blonde ale w/ 3 packs Notty) I've had good results (2nd place in light hybrid category at OC Fair homebrew comp, 22 entries in category).

First off, starters are not recommended for dry yeast. One rehydrated pack of yeast is more than sufficient for a 6 gallon .050 batch, anymore is a waste of money.


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bobbailey said:

if mr. Malty errs at all, it is likely on the side of over pitching. For a 1.050 beer, i would definitely go with 1 packet.

Bob

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+1

+1 on the single packet, properly rehydrated.

I start thinking about double pitching at around 1.070, but I also feel there is a large amount of fudge factor in pitching rate. Surely there is an optimum, but it likely depends on the particular recipe and brewer's methods.

Overall I was just curious about the results, good and bad.
Thanks everyone for the info. I will likely just hydrate one pack and pitch.

Homercidal said:

+1 on the single packet, properly rehydrated.

I start thinking about double pitching at around 1.070, but I also feel there is a large amount of fudge factor in pitching rate. Surely there is an optimum, but it likely depends on the particular recipe and brewer's methods.

Click to expand...

I agree. Pitching rate is such a WAG anyway unless you have the tools and ability to both count, test for viability, and measure vitality.

I do my yeast estimates (I wouldn't call them calculations) by hand now, since the Mr. Malty calculator doesn't take into account the effects of inoculation rate on growth factor in stepped starters. If I ever figure out how to use excel I'll make a little spreadsheet.