Harvesting Yeast

Are you sure you're using that much, sir?

Are you sure you're using that much, sir?

I don’t check my postbox at home very often – it’s usually filled with junk, and save for one or two bills, all my important mails come to work. So I was a little late finding this “Hey, do you realise your water consumption has shot up? Is there something wrong?” mail from the water board.

Looks like moving to smaller batches for partial mash and all grain has actually increased my water consumption! When I was going 14L boils and topping up to 21L, I was adding ice and a lot of water so – but when I moved to 14L boils for 12L batches, I then had to run gallons of water through the sink or (when I borrowed it) the IC.

I wonder what my water bill was before march, when I wasn’t homebrewing at all?

Unrelated to water costs, I’m thinking that I’m going to switch back from all grain/partial mash to DME+steeping for a while, and from 12L batches to 21L batches. All grain and PM are all well and good, but it just pushes me over the limit for making beer comfortably in the evenings. I need a few “easy” brews which don’t take 4-5 hours and leave me going to bed at 2am.

Saturday I went out and bought coconut to add to my Wheat Porter. Unsweetened from Tokyu Hands, this is what 5 x 45g packs looks like toasted on Sunday:

Lightly toasted coconut

Lightly toasted coconut

And with the beer racked on top:

Coconut in the secondary

Coconut in the secondary

This was after about 5 minutes in the secondary and I can already see the coconut going mushy. Smells delicious. In the hope of being able to keg this without the coconut following though, I’ve put a little plastic mesh thing into the tap hole. Hope it works.

I also partially bottled and kegged America v Britain Superpower IPA. The mix of British and American hops plays well together, but it’s still a bit sweeter than I’d like and I’d prefer the alcohol kick to be smoother. This is quite an unusual IPA with three different crystals, flaked rye, and wheat in addition to munich, 2-row, and extra light DME – and it will be very interesting to see how this conditions over the next few weeks. It attenuated better than the other IPAs I’ve made, going down from 1.072 to 1.016.

I was very tempted to keg Don’t Mention The War Pilsner also – it tastes amazing at the moment. I mean, really amazing – I’m not a huge pislner fan, but I could down this in one. I used all my willpower to resist though – it has only been fermenting for 2 weeks and is still at around 1.018 (if I remember correctly). It’s currently still quite cloudy, so hopefully a week or two more will clear it.

Finally, I decided to taste some of the fermented beer from the harvested yeast samples. I did the harvest in May. After fermenting out, I put it into the fridge for the yeast to settle, then when making the Wheat Porter I discarded the beer from the first fermentation and added new wort. With the second fermentation finished, it was time to taste. While the samples I took from the Baird tasted good and I could probably use them for starters – the sample from the German tasted very fruity and sour. Either this is because I forgot to sanitise the rim of the German bottle or because that yeast is old and funky or… who knows, but I just threw it away! Not sure whether I’ll use the Baird samples or not. What I wish I had done is cultivate from some Leffe, because I’d like to make a Belgian now.

More things thrown away to make space for beer yesterday. The casualty list continues!

Clothes or beer. The beer won.

Clothes or beer. The beer won.


Don’t make beer with a hangover, kids. It’s not big, and it’s not clever. You just end up making mistakes.


  1. Mixed up the grain bill for the recipe with my inventory of grain and only realised when I found the recipe supposedly called for 1kg of chocolate – way too much for a half batch. I’d already mixed Crystal by this stage and had to try to scoop some of it out!
  2. Added a full bag of DME before remembering that I’d upped the grain bill so I wouldn’t need to use DME.
  3. Started the mash at 68 degrees when I was supposed to be doing a stepped mask at 40.
  4. Added water to bring the temperature down, which is pointless because the grain had already been mashing at 68 – and you can’t go back. Advice from a homebrewing friend:

    When you really overshoot a temperature, there is really no return. The reason is that the different temperatures correspond to the peak activity of a particular enzyme or enzymes. Once you go above that temperature they tend to denature quite rapidly. So by the time you add your water and go back, you might have already lost the enzymes that you wanted.  So your best bet in those situations is to just take the temp you have and live with it.

  5. Let the lead from my new Ikea thermometer fall into the gas. It may claim to be resistant to heat upto 230 degrees celsius, but apparently not if that heat is from flames. Result? Calibration is screwed, taking my mash temperatures with it at the same time.

Despite all this, after recalculating the recipe to take account of the extra water and DME, I hit within 0.002 of the predicted OG – given that the recipe was all malted wheat, flaked barley, flaked oats, chocolate, and crystal – ie, no 2-row – there was a danger there wouldn’t be enough diastic power to convert the starch in the flaked barley and oats. So I’m pretty happy I got close.

Screw-ups didn’t stop when the beer was finished though – guess who made a special trip from Tokyo to Yokohama to go to Thrash Zone (for some serious IPA on draft) only to find out that the place is closed on Sundays? Yip. Me.

Second choice of Yokohama Cheers was also closed. Don’t people drink in Yokohama on Sundays?!

Yokohama Brewery

Yokohama Brewery

I ended up at Yokohama Brewery and I finally got my IPA fix there, not only with their “standard” IPA, but also from their new Green Fresh IPA (nice!)

It wasn’t easy though – Yokohama Brewery has two levels: Pivovar downstairs and the restaurant upstairs.. and they sell different beers! They refused to let me order a downstairs beer upstairs and I had to talk with the manager before they would nurse my IPA fetish with Green Fresh. And by the time I got my hands on Green Fresh, it was last orders.

Finally I got them to bring me Pivovar's menu

Finally I got them to bring me Pivovar's menu

Still, in the time I was attempting to get Pivovar’s menu, I did work through one or two other beers – everything on the upstairs menu actually, except the half and half:

The upstairs beer menu

The upstairs beer menu

Favourites were: White Ale (like Hitachino Nest White Ale but less strong), Pale Ale (very nice caramel taste – best of the standard beers), Amber Ale (though the pale ale was better), IPA (could have been hoppier, but nice bitterness – second best of the standard beers)

Middling: Pilsner (was a bit flat), Weizen (pretty standard), Alt (a little heavy)

Didn’t think much of: Fruit Ale

From the Pivovar menu I tried the Pixie Orange Ale, which I personally found a bit boring – the orange taste was too subtle to be refreshing, and the Green Fresh IPA. The Green Fresh was the star of the night, though some may find it a little too bitter.

Yokohama Brewery is here - Exit 5 of Bashamichi Station, walk straight and the turn right at the Richmond Hotel

Yokohama Brewery is here - Exit 5 of Bashamichi Station, walk straight and then turn right at the Richmond Hotel

I returned home to try Dogfish 60 minute, 90 minute, and 120 minute IPA – the 60 minute was passible, but the 90 and 120 minute were awful, tasting thick and gloopy. The 120m especially tasted almost like Scottish Ale – possibly not surprising since I’ve just found out the 120m is 21% ABV (though no actual ABV was written on the bottle; I found that figure by searching on Google).

They should have made me oh-so-hoppy

They should have made me oh-so-hoppy

I was expecting bursts of hop flavour from those beers. That’s no what I got. I actually couldn’t even finish the 90m and 120m IPAs. It was heart-wrenching throwing away half a bottle of 120m – it costs the same as Westvletern 12, ie. 1900 yen / 10 quid a bottle.

Finished off with Lagunitas Maximus IPA which tasted awful at first because the 120 minutes taste was still in my mouth, but better towards the end – not the hop monster I hoped for though.

Wheat Porter

Intended to be all grain, ended up with some DME in it (see story above)

Boil volume: 16L
Batch size: 14L (actually came out about 13.5L)

Predicted OG: 1.056
Actual OG: 1.054

Predicted IBU: 26 (though I FWH’d so may be up to 10% more)

Mash schedule (see story above):
11L at 59degrees for 15m, then should have been 68degrees for 60m but varied between 58 and 70
7L at 75 degrees for 25m
Cooling – In the sink (IC has been returned!) A little ice added at the end to make up batch volume and cool.

1.6kg Wheat malt
90g Crystal 150L (with a touch of 40L and 15L due to measuring cock-up)
300g Chocolate
100g Black patent
300g Flaked barley
300g Flaked oats
500g Extra-light DME

9g Nugget 14.6% – FWH + 60m. FWH from 87degrees, taking 10m to get to boil – so 70m total.
8g Nugget 5m

Yeast: S-04
I boiled 1L of water with 100g of DME to use for feeding the yeast I cultivated in May. I had 250ml of this left so rehydrated the S-04 in it. VERY active.
Pitched too high at 30degrees, but I had to go out and I didn’t want to leave the yeast unpitched.

I’ll ferment this in the chamber at 19degrees. I may get some coconut and rack some or all onto coconut.

Update: Almost forgot! I dry hopped Beer seventeen (America v Britain Superpower IPA) with 4.1g each of Fuggles and Cascade. FG is 1.016, which is a bit better than I achieved with S-04 and no fermentation chamber (this time I used US-05 and the fermentation chamber – I suspect the US-05 is a bit better at attenuating down than the S-04).

The yeast is active

The yeast is active

This photo was (rather badly) taken last night. On the left, the krausen has risen on the Baird Beer Rising Sun Pale Ale. This morning the krausen had fallen on that beer and risen on the Baird Beer Shimaguni Stout (right). There was about two hours time difference between bottling the Pale Ale and the Stout, hence the different fermentation times. These two beers actually use the same yeast but because I’ve harvested them from different beers, they will taste different.

In the middle is the German beer – as of this morning, nothing much is happening. It could be that the yeast was too old – or it could be just taken longer because I had less source to work with.

A couple of homebrewers have given me feedback on cultivating yeast.

From homebrewtalk, spage wrote:

I’ve always wanted to try this, however I have been hesitant because many breweries will brew with one yeast, and then bottle condition with an alternative yeast.

He also provided this link: Breweries that do and do not bottle with their primary strain

Another friend sent me this message:

My harvesting technique is often to rack the beer off the yeast I plan to re-use on brew day, during the mash or boil when I have some down time, leaving just enough beer on it to keep it liquid so I can pour it into a flask or jar.  Several hours later when the new batch of wort is in the better bottle at the right temp, I just toss it in.

Occasionally I put it in the fridge and save for use a week or two later.  Of course, if I do not re-use it the same day I usually make a starter.  I try to re-use for a similar style, or maybe one that is darker, so I don’t usually even bother to wash it. 

Before I started this experiment, I thought it would harvesting yeast would be difficult. Turns out it’s pretty easy.

Bubble bubble...

Bubble bubble...

...toil and trouble!

...toil and trouble...

The first batch

...but I got there in the end!

My first yeast harvest wasn’t entirely uneventful. I made too little wort the first time and had to make more; then the jug exploded in the sink (little tip: don’t run a boiling hot glass jug under cold water!); then I forgot to sanitise the bottle rim of the German beer before pouring the yeast into the wort; then I shook the stout too much between after adding bottle 1 of stout and had to spray inside with sanitiser before adding bottle 2 – but I got there in the end!

I made the pale ale with two source bottles; the German with one; and the stout with two. I may end up discarding the German yeast because of the sanitisation slip – on the other hand, I may use it for a small mash just to see what happens. This is my first time to harvest so I’m probably worrying too much – it really reminds me of homebrewing for the first time again, where you worry about everything! 

Method was the same as I detailed yesterday except that I used glass bottles instead of plastic. I sanitised them by boiling for 15 minutes rather than using spray or starsan. Hmm, now I realise I only boil sanitised.. did I sanitise enough? Oh gawd, there I go again. Just like a brewing virgin! This is fun..

I’ve not experimented much with yeast; with the exception of the kits I used when starting homebrewing and the Orange Wheat I made, I’ve pretty much used Fermentis S-04 English Ale yeast.

In my most recent grain order I ordered a variety of different yeasts. I now have: 

  • Safale S-04: A well known English ale strain noted for its fast fermentation and rapid settling.
  • Safale US-05: Ready-to-pitch American ale yeast for well balanced beers with low diacetyl and a very crisp end palate.
  • Safbrew S-33: Robust ale yeast able to tolerate high alcohol conditions, up to 11.5%. Used to produce a wide range of beer styles including Belgian wheat and Trappist beers.
  • Safbrew WB-06: The yeast produces subtle ester and phenol flavor notes typical of wheat beers.
  • Saflager S-23: Originating from the famous VLB institute in Germany, true lager yeast capable of producing continental lagers with a fruity, estery note.

This will give me some yeasts to experiment with – but what I’d like to do is grab some yeast from commercial beers, such as Hoegaarden and Baird Rising Sun Pale Ale. Rather than using a general yeast, those commercial yeasts are matched to the beer styles that I want to make – IPA, pale ale, and wheat. Using commercial yeasts will also give me more variety to play with. Hopefully I’ll find a yeast I like better than S-04 (which I have no particular attachment to).

Turns out it’s surprisingly easy to get yeast from a bottle of beer – as long as it is bottle conditioned and relatively young. From Homebrewtalk:

This is a Pacman yeast starter I harvested from a bottle of Rogues Brutal Bitter. I poured 3/4 of the bottle into a glass and drank it of course. I then made a starter of 16oz of water and 1/2 cup of DME and boiled. I then cooled the wort and sanitized the neck and mouth of the bottle and poured the rest of the Brutal Bitter into the starter and started spinning it. Super easy to do.

Homebrew Korea also has an excellent post on culturing commercial yeasts – though note that DME should be used instead of sugar, and personally I’d pour the 2/3rds of the bottle out before sanitizing.  How to Brew also has a page on using yeast from commercial beers.

Based on those sources, some others I’ve read, and discussions with homebrewers who harvest yeast, this is how to harvest yeast from commercial beers:

Harvesting yeast from commercial beers

  1. Sanitise a plastic 500ml bottle, then cap it.
  2. Boil 200ml of water with about 20g of DME for 15 minutes (10g for 100ml)  in a sanitised pot. This should give a 1.035-1.040 solution. (This amount was recommended to me by homebrewers who regularly harvest, saying that higher gravity worts could “stress out” the yeast.)
  3. Pour into the plastic bottle using a sanitised funnel, cap tightly, and cool to pitching temp.
  4. Pour about two-thirds to three-quarters of a bottle of the source beer into a glass, taking care not to disturb the yeast at the bottom. If you have two bottles of the source beer use both, because you’ll have more yeast to work from.
  5. Sanitise the neck and top of the source beer bottle(s) with spray sanitiser.
  6. Swirl the beer bottle(s) to ensure all the yeast is unstuck.
  7. Pour into the plastic bottle using a sanitised funnel, cap tightly, and shake to aerate. 
  8. Unscrew the cap slightly to ensure CO2 can escape. Label the bottle.
  9. Let it ferment for 3-4 days (longer if necessary – until fermentation stops), swirling a few times a day.
  10. This yeast can be used now with a starter. Alternatively you can make the yeast more healthy by culturing more. To do that, place in the fridge for the yeast to settle to the bottom. Once the yeast has settled to the bottom, prepare some more wort as per step 2, then take the yeast out of the fridge, discard some of the fermented wort (leaving the yeast at the bottom), and top up with new wort. Repeat step 9.
  11. Once fermentation is done, use within about 2 weeks. A yeast starter is recommended (see below).

There’s also a video on You Tube entitled Culturing Yeast from a Bottle Conditioned Beer – method is slightly different but principle is the same.

I also found two excellent sources on reusing yeast after fermentation: Mikebeer.net and a PDF from Point Brew Supply. The difference between these is that the second link covers washing the yeast. Combining these, this is the method to wash and reuse yeast from a fermentation:

Harvesting yeast from the fermenter

  1. Sanitise three 500ml bottles and a large container (about 3-4L, or two 2L bottles). Keep them capped/sealed.
  2. Bottle/keg the beer from the primary.
  3. Pour some preboiled and cooled water into the primary – about 1L.
  4. Swirl (not splash) until everything is in suspension.
  5. Pour the entire contents into the large container and cover with cling film.
  6. Let stand for 15-45 minutes until there’s a well formed layer on the bottom – the yeast will be in suspension above the gunk layer.
  7. Fill each bottle using a sanitised funnel – 1/3rd full first, then top them to 2/3rds, then fully fill – this is because the liquid at the top of the big container is less “yeast rich”. Leave behind the layer of gunk on the bottom.
  8. Label and date the bottles and store in the fridge. The yeast will settle to the bottom once in the fridge. Use within 2 weeks – a yeast starter is recommended if you exceed one week.

Reusing saved yeast

One bottle of the yeast should be enough for a 19L batch upto, say, 1.060. For yeast harvested from a previous fermentation and less than a week old, you can probably just add straight to the new wort – discard some of the top liquid first (because the yeast will have settled to the bottom) then warm it to pitching temp and shake before pitching. For everything else, or if you want to make your yeast really genki, a 1-2L starter is recommended.

To make a yeast starter, use 10g of DME per 100ml of water. Pour out some of the top liquid from the bottle of yeast, warm to pitching temp (by leaving out of the fridge) then swirl and add to the starter.

This video on You Tube covers making a yeast starter.