Smell of off-gassing? ( Bochet -- smells like banana )

[mediaguru]

Mead newbee here (newbie to fermenting anything in general, for that matter); already on my first batch, I have made many rookie mistakes, despite reading multiple forums (this one plus home-brew and winemaking ones) and books on winemaking (Compleat Meadmaker, and From Vines to Wines since the house I bought came with sangiovese vines...)

My mistakes included:
a) Rehydrating yeast too soon (I didn't realize I had to wait until my must had cooled significantly)
b) Not cooling must before pitching
c) Breaking a hydrometer on its first use (slid out of the container and hit the floor -- I used it anyway, because the glass that chipped off was under the weighted/sealed end, and nothing leaked out and it was still watertight/airtight inside. But it was now reading 1.01 in plain water, where it had been correct at 1.0, so I figured that was due to the missing glass weight and I just adjusted down my measurements accordingly)


I had decided to go for the gusto and charge right into making a bochet as my first excursion. Why? It sounded interesting and different, and I've had multiple types of meads but never one like that.

Boiled 15 lbs of light-amber honey for a little over an hour (not "scorched" or burnt per se, but pretty darn dark) and added to 4 gallons of water and 10g of Lalvin D47 dry yeast (rehydrated as a starter in a bowl of hot water, but I rehydrated it for over 40 minutes probably, that's why I got impatient to pitch)


My question is this: does it matter what the blow-off CO2 from the airlock smells like as it comes out? Does that indicate anything? Mine has a somewhat banana-like smell, and my biggest concern has been off flavors from pitching the yeast too hot. My must was probably 100-110 degrees in the bucket when I pitched the yeast. I have it stored in a temp-controlled refrigerated wine cellar (set at 65 degrees, but initially set at 55 for a few hours to try to drop the temperature quicker), so I hope the hour or two of exposure to hot must didn't stress the yeast and produce fusel alcohols and esters, etc. At first I thought I may have even killed them due to the hot temperature of the must, so I saved some of the yeast from the rehydration bowl and tried to preserve them as another starter for the next day (which I then pitched 12 hours later when must had cooled -- but it already appeared the yeast had multiplied and began fermentation, judging from airlock activity and the layer of foam on top)

Any way to tell, judging from the smell of the off-gassing (bubbling occurring about once per second right now, 3 days later)?

 

[fatbloke]

Mead newbee here (newbie to fermenting anything in general, for that matter); already on my first batch, I have made many rookie mistakes, despite reading multiple forums (this one plus home-brew and winemaking ones) and books on winemaking (Compleat Meadmaker, and From Vines to Wines since the house I bought came with sangiovese vines...)

My mistakes included:
a) Rehydrating yeast too soon (I didn't realize I had to wait until my must had cooled significantly)
b) Not cooling must before pitching
c) Breaking a hydrometer on its first use (slid out of the container and hit the floor -- I used it anyway, because the glass that chipped off was under the weighted/sealed end, and nothing leaked out and it was still watertight/airtight inside. But it was now reading 1.01 in plain water, where it had been correct at 1.0, so I figured that was due to the missing glass weight and I just adjusted down my measurements accordingly)


I had decided to go for the gusto and charge right into making a bochet as my first excursion. Why? It sounded interesting and different, and I've had multiple types of meads but never one like that.

Boiled 15 lbs of light-amber honey for a little over an hour (not "scorched" or burnt per se, but pretty darn dark) and added to 4 gallons of water and 10g of Lalvin D47 dry yeast (rehydrated as a starter in a bowl of hot water, but I rehydrated it for over 40 minutes probably, that's why I got impatient to pitch)


My question is this: does it matter what the blow-off CO2 from the airlock smells like as it comes out? Does that indicate anything? Mine has a somewhat banana-like smell, and my biggest concern has been off flavors from pitching the yeast too hot. My must was probably 100-110 degrees in the bucket when I pitched the yeast. I have it stored in a temp-controlled refrigerated wine cellar (set at 65 degrees, but initially set at 55 for a few hours to try to drop the temperature quicker), so I hope the hour or two of exposure to hot must didn't stress the yeast and produce fusel alcohols and esters, etc. At first I thought I may have even killed them due to the hot temperature of the must, so I saved some of the yeast from the rehydration bowl and tried to preserve them as another starter for the next day (which I then pitched 12 hours later when must had cooled -- but it already appeared the yeast had multiplied and began fermentation, judging from airlock activity and the layer of foam on top)

Any way to tell, judging from the smell of the off-gassing (bubbling occurring about once per second right now, 3 days later)?

The only smells to worry about are bad ones i.e. sulphur, rotten egg, etc.

Banana, toffee and similar are esters being produced by the yeast.

Oh, and making a bochet is the only reason to heat honey.....

10 grammes of yeast a.k.a. 2 packs ? any reason why ? as 1 pack is fine for batches up to 5 gallons.

D47 ? I do hope you've kept the ferment below 70F. As it's known to produce fusels above that......

 

[mediaguru]

Thanks

Well, as noted, the initial temp was much higher than 70. But I set the thermostat to 55 at that time, and then steadied it at 65 after a few hours, so yeah I am hoping I didn't ruin it. But this is my first batch of anything, ever, so I'm willing to bet it won't be perfect.

So, to answer the question: the pitched must was hot for potentially up to 3-4 hours, but has been a steady <70 degrees since then. Is that short of a time enough to ruin the batch? I wonder how much fermentation had occurred (it seemed to start up right away, no lag time. It was fully going in less than 12 hours...)


Why 10g of yeast? Because that's what I've seen recommended several places, such as the Compleat Meadmaker book. I've read that generally 5g is good for up to 2-3 gallons or so, so it can be a good idea to pitch 2 packs just to be safe (what I should have done is maybe pitched one though, and saved the 2nd in case that didn't work)

 

[akueck]

I wouldn't worry that much about the banana smell, it's in the realm of normal for yeast.

 

[Khan]

c) Breaking a hydrometer on its first use (slid out of the container and hit the floor -- I used it anyway, because the glass that chipped off was under the weighted/sealed end, and nothing leaked out and it was still watertight/airtight inside. But it was now reading 1.01 in plain water, where it had been correct at 1.0, so I figured that was due to the missing glass weight and I just adjusted down my measurements accordingly)

This concerns me. Alot of these hydrometers are made with lead as the weight, because of it's low melting temperature and the small amount needed to create a good counter-weight... at least I know that mine has lead in it (as well as all the ones that my LHBS sell).
.. SO... if you have exposed metal/lead in your mead, you might be about to poison yourself.. and that could explain some of the off-odors that you have experienced (if you left it in long enough to leach odors).

 

[mediaguru]

This concerns me. Alot of these hydrometers are made with lead as the weight, because of it's low melting temperature and the small amount needed to create a good counter-weight... at least I know that mine has lead in it (as well as all the ones that my LHBS sell).
.. SO... if you have exposed metal/lead in your mead, you might be about to poison yourself.. and that could explain some of the off-odors that you have experienced (if you left it in long enough to leach odors).

Well, I'm not entirely worried about it for a couple of reasons (I did debate it and go online to do some research before sticking it in):

1) The metal pellets to weigh it down were sealed inside a wax/plastic compound, thus no contact would have been made with the metal.

2) I doubt a quick dip touching a couple dots of lead would really be so bad even if it had made contact; after all, there is lead in my nicest wine glasses I own (see "leaded crystal", some of the finest stemware around; granted, there's no way I would want to store wine or brandy in a crystal decanter or anywhere it would sit for an extended period of time...)

3) Many people have said it is highly unlikely to have lead in your hydrometer, because it is illegal to put lead into food-use instruments (but then, how do my wine-glasses have lead in them? Makes me wonder...)


I need to be extra careful with my new hydrometer though, because the metal pellets are loose, not suspended in wax/plastic like the last one, so if this one breaks, they could all fall out (and I'm not sure what they're made out of)

 

[mediaguru]

No lead!

Okay, so I was smart enough to hang onto the little paper insert that came with my hydrometer even though I threw it away. It came with my wine kit from Northern Brewer and is "Alla - France - Wine & Beer Hydrometer ... LEAD FREE"

So, that answers that (it didn't look like lead... more like steel or maybe tin, but I doubt tin would be heavy enough?)

My new one, however, from the LHBS... is very generic, just says "Made in Japan", and the metal pellets are NOT suspended in wax or anything, and they sure as heck do look like lead (they have that beautiful shimmery dark pewter color...)

Looks like I might be getting my hydrometers from Northern Brewer from now on (they're only $5 there anyway, and my LHBS sold this one for $8, but I was in a pinch and couldn't wait -- nor wanted to pay -- for shipping)