A short lesson in Herding Yeasties
April 15, 2012 § Leave a comment
On Saturday the 14th June, I was Kindly invited down from Sunny South Cheshire to a Friends 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”
Which 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, I felt tired and a bit dozy due to the fact that I had struggled to get to sleep the night before. I was so looking forward to a day out with friends, and learning, that at midnight on the Friday I remember feeling like a six year old waiting for Santa to come. (a bit sad for a 41 year old I suppose, but at least I know I haven’t lost some of the child in me 🙂 ). The drive down was uneventful but pleasant, & the sun illuminated the green midlands fields as I traveled along the A50 towards Burton on Trent. ( I have done the Drive to Burton hundreds of times but it had been 6 months since the last time I had made a visit and the route to my destination was sending me straight through Burton) as I entered the old town, I felt a strange emotion, the sort you feel when coming back home after living away for a few years. Strange really as I only ever worked in the town, for four years, but Beertown holds a special place in my heart, its the sort of place you just have to go look see and spend some time in if your into beer. There are a few magical taverns with some excellent locally produced real ales if your prepared to go look, & I know more about the history of Burton on Trent, than I do about my hometown of Macclesfield, (strange how beer interests more than Silk.) I just had to pull up get out of the car and breathe in the air and take in the unique smell of the town. However it dawned on me that I needed to get a reality check, if I didn’t get a move on I would be late for the meet, therefore I set the controls for the heart of the sun and crossed the great stone bridge over the mighty River Trent and journeyed onto my destination just north of Market Bosworth.
Pulling up the Gravel Drive of a large bungalow, I was met by Allan G, (Allan is a member of the Midlands Craft Brewers, very passionate about Home Brewing, his local group of brewers, and I always look forward to spending a few hours with him, as he is a great character and just one of those people you just cannot help but like). 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, & 2o 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
- Yeast storage and management is well within the grasp of anyone
- 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 its not a draughty/environment.
- You must be a stickler for cleanliness and sanitation, (however if your 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.
Airbourne 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.
We had a brief discussion on Dried yeasts, their pros & cons and went through the tips and tricks to getting the best out of dried yeasts should you not have time to manage or prepare a liquid strain.
Why use Dried Yeast?
- cheap as chips
- easy to store (but you should store in a fridge at home
- time saving
- easy to use
The main thing to take from this is if you do nothing else, ALWAYS re-hydrate dried yeast with boiled water with a temperature of at least 26 deg Centigrade, (its surprising how many people that go to the trouble of making an all grain beer (5-8 hours of work), then they bugger up their chance of making the best beer possible, by sprinkling a pack of dried yeast on wort at 18-20 deg,) sprinkling kills a great chunk of the dried yeast, (so always re hydrate with boiled cooled (26-35 deg C) Water, you will get so much better fermentation and better beer as a result).
We then went to discuss the Liquid yeast strains available to everyone in the UK.
I will add here that if you want to really dial in a flavor in a beer you intend to make a bit of online research and prudent yeast choice, is going to pay dividends in your finished product, Dried Nottingham is not going to give you a decent hefeweizen, so if you want to add that extra dimension, take some time to experiment, it will pay dividends. I will also add if you learn to make slants, you will probably only ever need to buy one particular strain ever again, Liquid yeasts are not expensive if you know how to look after them.
Yeast strains are available from White Labs and Wyeast both american brands and available in many online Homebrew suppliers, But make sure they keep the vials in refrigeration, or you will be asking for trouble. Brewlab in Sunderland is also a very affordable and good source of liquid yeasts already supplied on slant. & if you want to pay the earth you could also try the national collection of yeast cultures
It was then time for lunch and a stretch of the legs, I had a good chat about what we had learnt and had the usual discussion on equipment etc with the other brewers (its amazing what home brewers get up to tinkering & making things in their sheds and garages, to make life easier brewing) & I dined on a diet of Leicestershire Cobs washed down with a spectacular Galaxy light Bitter, kindly given to me by Peter F. (over the years I have tried a number of hobbies, Fishing, Road Rallying, CB radio, etc etc, however I have never ever come across a more agreeable and friendly crowd as the lesser spotted home brewer, and long may it stay that way I have never gone to a meet and left empty handed, or not tried a new beer)
The method is to make a starter wort to a gravity of 1035og, then add agar flakes or powder, (plenty of places sell it, but asian shops are usually the cheapest source), pour into 30-50ml sample bottles, fill about 1/3rd full,place the sample jars in a pressure cooker and steam for between 15 and 30 minutes at full steam to sterilise the sample slants.
(note when doing this you need to a) ensure the the bottles are upright in the steamer b)the bottles are made from polyprop or glass, not plastic or they will melt in the heat C) you have cracked open the lids on the bottles, to allow gas equalization, failure to do this will result in a few small explosions in the pressure cooker and a mess for the wife to clean up 🙂
Once steamed tighten up the lids on the bottles so they are sealed, and place resting on an angle until they set, about 20-30mins waiting time. Once the agar/wort mixture has set you are ready to start the innoculation culturing process.
To Innoculate, is pretty straightforward you need to flame your wire, open your yeast vial, White labs, etc, dip the sterilized wire in the yeast.
Then streak the yeast on the wire over the surface of your prepared slant, ensuring you don’t leave the pots open for long in between operations, and also ensure you work close to the flame source at all times.
Once streaked you then put the slopes in a temperature stable warm environment (20 deg constant is ideal) with the lids slightly cracked to allow co2 release, for 3-4 days, (you will see the yeast culture growing on the surface of your agar slant during this time, great for keeping the kids amused). & once you have given it 3-4 days the slope can now be stored in a fridge for up to 6 months safely with no real detriment to the yeast strain. If you want to keep the strain going indefinitely, you repeat the process every 4-5 months and streak from your stored vial, onto a freshly made one, yet another hobby & I am introducing you all to “Culture” (I’ll get my coat).
By doing the above, you are able to over time, build up your own yeast bank, and if you can get your fellow home brewers interested in this practice, you will have yet another thing to swap on meet ups 🙂 Win Win for everyone.
Summing up I had a great day out, I would like to thank the Midland Craft Brewers for inviting me, I learnt a very simple but effective technique & its something I intend to do going forward. & I hope my ramblings have inspired you to go and have a go yourself.
For further information on Yeast & Brewing try the following resources
Yeast Culturing FAQ by Mike Sims clear guide to making slopes
Yeast By Chris White & Jamil Zanasheif This is an invaluable book for all homebrewers and it will unlock a lot of useful knowledge as well as help you understand yeast better.
If you want to learn and also meet plenty of like minded individuals who will be more than happy to help you make great beer then get in touch with the following groups.
Midland Craft Brewers Cover West and East Midlands area, plenty of meetings and lots of knowledge in the group
Northern Craft Brewers (cover northern england from south cheshire/north staffs, to Scottish Borders, and also lots of members & meetings in Yorkshire)