Yeast Day 14th April 2012
The event was organised so that MCB members could learn the intricacies of yeast cultivation under the guidance of our two experts, Alan Q and Peter F. Also present was Shane S from the Northern Craft Brewers, who kindly put together the following account of the day.
A Short lesson in Herding Yeasties
On Saturday the 14th April, I was kindly invited down from sunny South Cheshire to a friend’s house in rural Leicestershire. Several members of the Midlands Craft Brewers had gathered to learn how to herd and nurture yeast & I was going to be one of the lucky ones who was going to be learning the dark art of yeast management.
Now I have pretty much used liquid yeast for the whole time I have dabbled in home brewing, and there have been a number of reasons for this, the main one being that due to a few contacts I could pretty much get hold of very viable brewery yeast that made great beer, free anytime I wanted, and there is nothing quite like getting something for nothing.
The other reason was that by using a secret liquid strain, I felt I could make beers that would differ from my peers, who were all using Nottingham, SO4 or US05 Dried yeast. Now don’t get me wrong dried yeast is used by plenty of award winning home and commercial brewers the world over, but I personally think that the commercial dried strains tend to be very very neutral, and feel that the brewers that stick to dried yeasts are missing an extra dimension in their beers, after all “Brewers make wort & YEAST MAKE BEER”
This brings me to the reason I had jumped at the chance to learn how to become a member of the “Secret order of Yeastie Shepherds”. I had a career change last year, and as such my supply of my main ingredient dried up. I knew how to pitch yeast into my beers at the optimum quantities and could keep the same batch of yeast going no worries for about 8 brews or gyles, before I needed to get some fresh. But I didn’t have the knowledge of how to store yeast in a stable manner for use at a later date, or how to keep a strain healthy and to hand indefinitely.
I set off down to Newbold Verdon early on the Saturday. On arrival I was met by Allan G, (Allan is a member of the Midlands Craft Brewers and very passionate about Home Brewing). I hadn’t been in the house more than 2 minutes and I had a cup of tea, a warm welcome, and we were well into discussing manufacturing new brewing equipment. Twenty minutes later 10 Amateur Brewers were waiting expectantly in the kitchen, ready to learn how to become better brewers and learn yeast management.
The Agenda for the day was to be full & we were to learn plenty.
1. Welcome and Introductions (AG) 10.00-10.15.
2. Aseptic Technique (AQ) 10.15-11.00 (to include practical)
3. Sources of yeast (PF) 11.00-11.15
4. Reusing Yeasts (PF) 11.15-11.30
5. Storage including viability of stored yeast (PF) 11.30-11.45
6. Propagating yeasts (PF and AQ) 11.45-13.00 (to include practical1 and 2)
7. Lunch 13.00-13.45
8. Strain Maintenance (PF) 13.45-14.00
9. Splitting vials (PF) 14.00-14.45 (to include practical3)
10. Temperature control (PF) 14.45-15.00
11. Problem areas (AQ) 15.00-15.15
12. Use of Microscope (AQ) 15.15-15.30
13. Summary and Conclusions (AG) 15.30-15.45
14. Feedback (ALL) 15.45-16.00
Alan Q, opened the proceedings and we learnt a few key things
You don’t need hundreds of pounds worth of equipment. A pressure cooker, a couple of pans, some sample pots a glass measuring jug, a wire inoculation needle, a blowtorch and a spare fridge (freecycle) is all you need for success. You can do all the work (should read enjoyable pastime) in a well prepared kitchen as long as it’s not a draughty/environment.
You must be a stickler for cleanliness and sanitation, (however if you are already making decent all grain beer, this should be second nature)
If you want to be successful propagating and storing yeast you also need to understand where you can go wrong. The biggest issue is contamination, from unwanted organisms, i.e. wild yeasts and bacteria.
Contamination of a slant and your yeast culture can occur in 3 ways.
Airborne contamination: (To avoid this, ensure all windows and doors are closed, ensure people are not coming in and out of the room you are working in, and only open and close the storage media when required to, for as short a time as possible and work in close proximity to a flame, such as a camping gas single burner or blow torch)
From the equipment being used: (To avoid this ensure you clean everything spotlessly and then sanitise all the equipment that will come into contact with yeast)
From yourself: (To avoid this, roll up your sleeves, take your watch off, scrub up, use an alcohol wash, and cover your hair if practicable)
We then went onto practice flaming a wire innoculator, flaming a glass pipette and transferring 1ml of liquid from one pot to another, extremely nerve racking when done with an audience (my turn came and I relived the terror of my first science class aged 11). Opening jars and keeping things clean and ordered is also a lot harder than it looks, but a doddle once you know the secret handshakes
Following the terror of a practical, Peter F, a very active member of The Midlands and also The Cambridge Craft Brewers continued the talk.