Mangrove Jack yeasts

[PeeBee]

With dried yeasts I tend to be a bit blazé - If it's in date, chuck it in, if it's out of date by just a few months, well just chuck it in too though I may put an extra half packet of the same yeast in if I've got it (that's a pain 'cos I end up throwing away the split pack a few days later). Works okay, but I'm getting reminders that this is a dodgy philosophy:

I'd been using Mangrove Jack's M44 yeast ("West Coast") for a particular recipe and knew it could be slower than I'm used to. Recently I tried MJ's M36 "Liberty Bell" (their old "Burton Union" yeast) and it's being really s-l-o-w! Going by its old name I was assuming it was British in origin and would speed through the fermentation. Not so it seems.

Warning: I define a fermentation of three days or more to be unacceptably slow (and this is also another excuse to show off the pretty graphs created by a Tilt PRO!).

Capture-FOUR.JPG (24.49 KiB) Viewed 2816 times

It's still going but should be done by the end of the day (over four days!). Dead steady (I normally expect some acceleration in rate), but it's showing all the signs of being significantly under-pitched. The "bump" near the end of the plot is accumulated yeast falling off the Tilt as it "tilts" more upright; I'm getting used to this predictable quirk.

So ...

I want a better policy with dried yeasts.

Most yeast packs contain 11.5 grams. That supplies a surplus of viable yeast cells when new, but at BBE date there might be less than 50% viable. But Mangrove Jack packs are 10 grams, just enough if the packs are new, but at BBE date there will not be enough viable yeast to ferment the volume stated. An if the packs aren't kept cool, expect it to be much worse. And what is BBE date anyway? Some say 36 months from manufacture, some say 30. The MJ yeast graphed above was a few days short of BBE date.

With more free "next day" delivery vendors available I'm beginning to think of zero yeast stock at home. Just avoid year old packs whatever the BBE date says (it's BS).

[bitter_dave]

Could this not just be the case of different types of yeasts behaving differently? Some yeasts are marketed on the basis of being fast. I've used liberty bell loads for 23 litre brews, of varying ages, rarely stored at fridge temp. Always been fast at fermenting. Not saying quantity or age of yeast is unimportant. However is the graph you show really a problem if that's how the yeast behaves?

[clarets7]

I found the same thing with my last brew, very slow start to the point I was getting worried. Didn't realise they were only 10g, wish I had rehydrated it first. First few pints seem to confirm that I have under pitched

[MashBag]

Personally I am with Dave. So we need more graphs!

[clarets7]

Maybe a batch thing? I've thrown the packet away which is unusual for me.

[bitter_dave]

I found the same thing with my last brew, very slow start to the point I was getting worried. Didn't realise they were only 10g, wish I had rehydrated it first. First few pints seem to confirm that I have under pitched

What would be a sign of under pitching (aside, obviously, from high fg which I'm assuming was fine)?

[PeeBee]

... However is the graph you show really a problem if that's how the yeast behaves?

Let me post up another graph, this time of S-33 fermenting:

Boddingtons Stout 1901 trace.JPG (25.33 KiB) Viewed 2795 times

Very similar to the previous post. Similar gravities, similar temperatures ... but the timeframe (horizontal axis): a third as long, the fermentation is three times faster and you can see the Tilt being buffeted by the evolution of CO2 gas (spiky trace). By comparison, the M36 is limping.

But you might be right? It is as that yeast behaves. I'd never used it before and probably mislead myself into thinking it was "British" style. They changed its original name for some reason, perhaps because it misrepresented the yeast. People describe it as "fast", but MJ don't ("fast" is a very subjective term). But MJ do describe it as "Suitable for both English and American Pale Ales, Extra Special Bitters, ... ", another very subjective term.

But if that was a yeast I was used to, it would be behaving as under-pitched. And as it was a 10g packet almost three years old, it was under-pitched!

[clarets7]

It just didn't taste right from the fermenter, a bit harsh. Went into a barrel at 1013 to finish off, should have left it longer. I'd fermented the initial hydrometer sample out with the same yeast and that was absolutely fine. Tried it from the barrel every few days over the last few weeks and the harshness gradually went, it is perfectly drinkable now but nothing to write home about. I've used MJ Burton Union and Liberty Bell before and not had these problems, but that was with 19L brews, just checked and this was 25L so definitely under pitched, I will know next time.

[bitter_dave]

It just didn't taste right from the fermenter, a bit harsh. Went into a barrel at 1013 to finish off, should have left it longer. I'd fermented the initial hydrometer sample out with the same yeast and that was absolutely fine. Tried it from the barrel every few days over the last few weeks and the harshness gradually went, it is perfectly drinkable now but nothing to write home about. I've used MJ Burton Union and Liberty Bell before and not had these problems, but that was with 19L brews, just checked and this was 25L so definitely under pitched, I will know next time.

Out interest what was the OG?

[clarets7]

Sorry, thought I'd put that. I was aiming for an ordinary English bitter at 1036, but ended up at 1039. Was expecting it to go down to 1010 but just checked and it's 1008 now - BUT, I seemed to have not saved the notes, and I know that I liquored back to get the volume I needed so it may have been 1036 . Must try harder...

[MashBag]

What would be a sign of under pitching (aside, obviously, from high fg which I'm assuming was fine)?

Underpitch is not necessarily a problem but it will cause a extended yeast lag. This is the period when dried yeast gets used to it's surroundings.

One of the key stages is it goes from aerobic (mulitplying up) to anaerobic (making hooch).

This very subtle, bar two signs. Extended lag (aerobic) is often accompanied by what I can only describe as a carpet glue smell. This will be hard to detect on small batches.
The anaerobic phase is normally signalled by the start of the co2 being produced.

Nutrition and avaliable fatty acids will also affect. But that is another whole box of bicycles.

[clarets7]

You're right Mashbag, an odd smell which could be carpet glue , it was very faint on my last brew but it does go in time. Just annoying when you've run out of beer and have to wait...

[PeeBee]

Well, I never got what I started this thread for: An improved policy for dealing with dried yeasts. Especially from cheap-skate manufacturers like Mangrove Jack. But working the subject through this thread has been useful in creating my own idea of a policy. And I have attracted comment doubting my ability to recognise an under-pitched yeast: I'll update that graph ...

Capture-FIVE.JPG (24.76 KiB) Viewed 2754 times

Throwing a bit of technology at it! Would have preferred it to lose another couple of "gravity-points" but I'll live with 1.011. I can't trust my ability to detect "carpet glue", and anyway, if you can it's already too late. Okay, forget the time it takes (five days, seems that is still "fast" by some people's ideas), but that trace looks like it has been drawn with a ruler. There's no "life" in it! And pitching an inadequately size (10g) pack of yeast at end of its BBE date is just confirmation of under-pitching if I need it.

So, the policy:

Ignore the BBE date on dried yeast packs. Never buy more than you're sure of using in the next six months. Chuck away any you've had for over a year (or within two years of the pack's "BBE" date). Keep the packs in a fridge (as if you don't already?).

Using any packs outside these specifications may backfire, and waste the time and money spent on the entire brew. It's just not worth it.



Next thread: Seems I've been keeping my base malts a bit too long as well?

[MashBag]

Using any packs outside these specifications may backfire, and waste the time and money spent on the entire brew. It's just not worth it.

Please don't take offence but, in the interest of balance for future readers.....

The whole brew is not lost. Repitch.
Perhaps consider having a backup yeast to hand.
If in doubt do a proper rehydration.
If in doubt double pitch.
Storage conditions make a HUGE DIFFERENCE. A vac packer is your friend.
Yeast is not and never will be black and white. It is a living thing.

I have perfectly stored dried yeasts that I use (with confidence) out of date with no issue. I have also had suppliers send stuff sent to me in a cooler bag with an ice pack.

I like your idea of a policy, but just not sure one dude fits all.

[PeeBee]

... I have perfectly stored dried yeasts that I use (with confidence) out of date with no issue. ...

My approach entirely ... until it all turned to rat poo.