elderflower as a source of wild yeast

[Microscopist]

It's that time of year again and after a couple of attempts I've got a good strong ferment going in a batch of elderflower 'champagne'.

A couple of questions -
firstly, anyone know what species are likely to crop up in such a brew?

secondly -
I'm wondering if the yeasts in it might make for an interesting wild fermented beer? - Not elderflower beer - I plan to subculture a couple of times to make sure the flavour of the flowers doesn't come through. Anyone tried?
Thought I might do a small ( 1gal ) batch using just 2row pale and goldings to investigate.

 

[Microscopist]

So it begins...

The elderflower brew tastes fine and has a respectable foam on the top.
That was 200g sugar in 2l water, juice of one lemon , 1tbsp vinegar boiled, cooled and 8 fully open flower clusters collected from different trees immersed and left for 2 days. Showed fermentation after 3 days and I'm now 7 days in. OG 1035


I've just boiled up half a kilo of pale spray malt with 8g goldings for 60mins 5l OG 1035

Split a little off into kilner jars and diluted one of these 50%. Innoculated with some of the foam and liquid from the elderflower - the surface was covered in stringy, slimy layer - no off taste to the slime.

Rest of the elderflower will be bottled in PET tomorrow to carbonate ready of drinking and as a back up.

Going through the literature the majority of nectar yeasts are Metschnikowia which I know nothing about other than it's a budding yeast and makes alcohol.

 

[Microscopist]

Good amount of foam on day 3, now settled into bottom fermentation. Smells of honey and toffee, no idea what that tells me.

 

[sweetcell]

nothing to add, other than "cool". keep up the good work.

 

[Microscopist]

I've taken pics as I went along, sooner or later I'll get them off the camera. It's not the best image as I'm fixing the 'scope at the moment but this is what's growing in there at 100x under DIC illumination.

 

[Microscopist]

Up until Friday this lot had been sitting in a stainless steel pot but I needed that back so I transferred the brew to a demijohn. The disturbance has kicked off a rapid jump in fermentation rate and the reappearance of the surface foam.

Smells and tastes almost exactly like the pale Leffe - more so that any of my attempts to actually brew leffe. The residue left in the testing jar ( I didn't tidy up ) has gone powerfully acid over the weekend.

Original elderflower batch is drinkable and has a light lactic tint to it.

 

[Microscopist]

I got round to doing the photos -
elderflower starter at 10 days-


Wort 5l inoculated with 100ml starter - 24h after pitching


Same wort at 5 days


High grav jar at 6 days

 

[Microscopist]

Lower gravity wort plated out on MEA - 3 days


and the higher gravity with some camera shake


I've picked 5 colonies from each plate and put them into 10ml of a basic malt broth ( pale spray 75g in 500ml plus 250mg yeast extract - OG 1020 ) filter sterilised, now comes a bit of waiting...

The lower gravity gives a higher cell count and a different odour but I can't see a great deal of variation in colonies - some are slightly whiter but that's about it. My streaking could have been tidier but I'm used to working under a hood - I don't have one at home so I try to keep things open for as little time as possible.

I have two plates under the time lapse rig, I'm going to let those overgrow a few more days.

 

[dantheman13]

Very cool!

 

[Microscopist]

The cultures in universals are nicely cloudy, just sampled the demijohn as I'm moving in a few days and it's still fermenting. Current SG is 1.004! I'm going to stop it now. As it's a small batch I'll use two PET bottles to allow it to carbonate and settle.

Had a taste - a little thin - but I'd expect that from such a basic wort. Extremely fruity, lightly tart and in every way drinkable, lingering fruit aftertaste too. Chilled and fizzy it could be great.

Maybe it's because I was drinking them all last night ( and this afternoon ) but I'd say what I have here is a saison.

I'll press on with testing my ten isolates and brew up a big batch when the dust has settled from the move.

 

[Microscopist]

Now there's interesting - Just been poking around in the fridge and the lower gravity wort culture ( og 1017 ) is still showing activity, fridge has been at 2c all week 'cos I'm clotting cream.

New plan after move - plate out and incubate in the fridge and see what crops up.