Using yeast dregs

[WestEnder]

Hi,

So I'm planning on brewing a few more batches before I even attempt this but I scored a bottle of this at the weekend and was looking at the yeast at the bottom and wondering about it given what I've read about Orval and the use of the dregs at the bottom of the bottle.

Before I even attempt this (probably not till the summer), I have a few questions...

How much dregs do you need? One bottle's worth? A few bottles worth? I brew 20 litre batches.

How long does it last? What's the best way to preserve it before use? How long can you preserve it for?

Are there any other pitfalls? I assume this being wild yeast etc there's a lot more that can go wrong? Anyone brewed with wild yeast or dregs that found anything unexpected?

Cheers!

 

[Spoon]

You'll need to make a starter. There's 2 options:

1) Single cell starter, this involves laboratory equipment, sterile conditions (not just sanitized) and lots and lots of steps. The good thing is the yeast in petri dishes or on slants can last a very long time as it only needs one viable cell, not thousands/millions/billions and it avoid any sort of selection (taking yeast from krausen, or the bottom of FV's can tend to favor those cells that do/don't floculate if you only use one method). The downside is you'l have to do many, many, steps to build up those few cells to a few billion needed for a batch. This is how the laboratories and breweries can be sure that every brew is using the same strain of yeast. In theory there might be enough yeast even in beers that don't have any visible sediment in them to work this way, you'll find out in the petri dish whether there was anything viable.

2) Chuck the dregs of the bottle into a conical flask with a pint of wort made from DME, stick it on a stir plate and give it 48 hours, allow to settle, decant off the 'beer' and repeat until the cell count is about right.

If you google yeast starters, and preparing yeast slants you should find a lot of information and instructions.

In terms of equipment for making starters you'll need a stir plate (and stir bar) and conical flask. For growing yeast from slants you need things like petri dishes, centrifuge tubes, pressure cookers (or an autoclave), etc.

 

[WestEnder]

Cheers. Having read a bit more it seems a lot of folk use dregs for secondary fermentation. This seems like a gentler way in, although I do wonder what the yeast would feed on there?

 

[MyQul]

I've bottle cultured a couple of time (but not lambic/wild yeast). Here's my wee guide on how I did it

http://www.thehomebrewforum.co.uk/showthread.php?t=53567

 

[WestEnder]

Interesting - and I never knew the name for those sciency looking glass beakers you see when people make starters. :)

The best thing is that you've answered the question about time. I sounds like I can spend a few weeks seeing if it works before I commit to buying the rest of the ingredients.

 

[markcc]

I've read that fantome has lacto in it and that if you culture the dregs, the lacto outgrows the sacc and brett and you'll end up with something super acidic. Fine if that's what you're looking for.

I'd use whatever saison yeast you're familiar with for primary and then pitch the dregs (cultured or direct from the bottle) to secondary.

 

[johnnyboy1965]

The trouble with re-using a wild yeast strain is the it will mutate over time. The "stronger" yeast strains will dominate. If your just "playing" for the time being you can use a couple of jam jars, until you get hold of a conical strainer. Have a practice with some cheap dried yeast. A stir plate is a good project to build yourself and very beneficial (there are loads of "How to" on goolge) and all the components are available online or at Maplins (approx£45.00).
When dealing with yeast culitivation everything must be sterile and not just sanitized.