Monday, 24 September 2012

Blow-off Cap


Woke up this morning to find the yeast (pitched 12 hours ago) crawling out of the top of the jerry-fermentor and making a mess of the fridge:
... so I figured it was time to make a 'proper' blow-off cap.

All it takes is the cap from cube or jerry, plus a 13mm barb to 15mm BSP poly elbow or director:

Drill a very-slightly too small hole in the middle of the cap, the 20mm hole saw is ideal, but a step-bit will work too.
Cut a thread with a 1/2 inch stainless nipple (or similar):

Screw in the elbow/barb:

Hole in the lid of the blow-off-vessel:

... and it's done:


It is in action less than 5 mins later:

It took longer to clean up the mess in the fridge than to make the blow-off-cap.

Sunday, 23 September 2012

Brew Day: Old 'n Brewed

The second of three "traditional English Ales" being brewed for my sister's wedding next month.

A fresh/newly brewed Old Ale in returnable bottles seems to fit each each line of the old wedding tradition/poem (if we modify the last one) which gave this beer it's name:
Something old,
something new.
Something borrowed,
something brewed.
The recipe is Theakston Old Peculier from the Brew Your Own British Real Ale book, with a very slight increase in gravity and Magnum hops used in place of Challenger.
Old 'n Brewed
Style: Old Ale
Batch Size: 24.00 L  
Boil Size: 33.10 L
Estimated OG: 1.059 SG
Estimated IBU: 29.4 IBU
Estimated Color: 24.1 SRM
Brewhouse Expected 75.0 %, Achieved 80%
Boil Time: 90 Minutes

5.50 kg  Pale Malt, Maris Otter (Thomas Fawcett)
0.30 kg  Crystal Malt - (Simpsons) (57.0 SRM)
0.21 kg  Chocolate (Simpsons) (630.0 SRM)

14.00 gm  Magnum (11) [12.20%]  (90 min)  21.3 IBU
14.00 gm  Fuggles [5.60%]  (90 min)  9.0 IBU
15.00 gm  Goldings (HG 12) [4.50%]  (10 min)  1.5 IBU
5.00 gm  Goldings (HG 12) [4.50%]  (Dry Hop 3 days)

1.00 gm  Epsom Salt (MgSO4) (Mash)
1.00 gm  Sodium Bicarbonate (Baking Soda) (Boil)
1.50 gm  Calcium Carbonate (Chalk) (Boil)
5.00 gm  Calcium Sulfate (Gypsum) (Mash)
10.00 gm  Calcium Chloride (Mash)

1.00 gm  Yeast Nutrient (Boil 10.0 min)
3.60 gm  Brewbrite (Polyclar) (Boil 10.0 min)

F40 (BrewLab #F40) (2.2L Starter)

Mash Schedule: Medium-Full Body, HERMS Step Mash
Mash In  Add 16L of water, rest @ 55.0 C  5 min
Maltase Rest  63.0 C  15 min
Dextrinization Rest  72.0 C  60 min
Mash Out  78.0 C  10 min
Grain bill in the new grain hopper:
The new hopper holds the 6kg of grain with ample-room to spare, so it will be big enough to hold all the grain for most-any single batch of beer.

Water adjustment salt additions added to the mash (more were added to the boil):

The new Kaixian pump and new HERMS vessel:

Having recently reduced the roller-spacing to produce a finer grain crush (and increase efficiency) there is more fine flour in the mash.  While this was fine, last batch, with the less powerful little brown solar pump, with the new Kaixian pump (used here for the first time) the grain bed compacted and severely restricted the mash recirculation rate.  I resolved the problem with two 200g additions of Rice Hulls, giving the grain bed time to settle before turning on the pump, and then only opening the valve (on the pump outlet) slowly, however the mash-in step took much longer while it was all sorted out.

Before I build my brew-stand I wanted to brew with a single-level configuration (easier to see, maintain and manage than the HLT on a higher level), but since I prefer to fly-sparge, a second pump was used:
To achieve the required slow fly-sparge flow rate (0.5 to 1L per min) the outlet valve on each pump was mostly-closed, but - hopefully - being magnetic drive pumps this should not hurt them ... but time will tell.

With the addition of the Rice Hulls - and some stirring and 'chopping' of the top of the grain bed, there was no noticeable channeling, even at the end of the sparge:

A much more homogeneous grain-bed than last time:

The pre-boil gravity reading indicated that the efficiency would be a little higher than expected, so I added slightly more bittering hops to a total of about 31.5 IBU.

10 min additions of Brewbrite, Yeast Nutrient and Golding Hops:

These Kaixian pumps are only rated for use up to 80degC, and when tested slowed dramatically when pumping boiling cleaning water.  When emptying the kettle it might be better to put the pump on the cold-side of the plate chiller, but I wanted to see if/how the pump would work on the hot-side.  At the end of teh boil, the pump worked fine to recirculate hot water (95C) to sanitize the plate-chiller and then it worked without issue to drain the kettle (immediately after boiling):
The pump provided for a much higher flow-rate than gravity or the little brown solar pump, and the fermentor was filled in just a few minutes, however, even when the cooling tap water flow was as high as possible (something I have never needed to do before) the 30-plate plate chiller did not quite chill the wort as effectively as usual.  At this time of year, when the tap water is about 15degC, wort into the fermentor is usually only a couple of degrees warmer, but was about 21.5degC.  Next time I'll need to throttle the pump just a little so the plate chiller has enough time better cool the wort.

It's only the second time I've used Brewbrite (Polyclar) - a  mix of purified food grade Carrageenan and specially modified PVPP - which is intended to be both kettle and fermentor finnings.  So far I've not noticed as much break material forming in the kettle, but will see how clear the beer turns out - it looked OK going into the fermentor:

I used a stronger aquarium air-pump to aerate the wort this time - it still didn't like the stainless air-stone, but it did produce significant surface-disturbance and even over-flow bubbling:
The fermentor opening (and bubbles) are protected under a sheet of cling-wrap, but it still made a bit of a mess.

Since it's a higher gravity Old Ale, I was planning to re-aerate the wort 12 and then 24 hours after pitching the yeast, especially since the volume of east in the starter flask appeared to be slightly less than expected.  So I left the air-line in the fermentor when it was put in the fridge:

However, the next morning (12 hours after pitching) the yeast was crawling out of the top of the fermentor, and there was no way I'd be able to re-aerate without making significantly more mess:

To prevent any additional over-flow mess, I made a blow-off cap and ran the blow-off tube into a glass bottle.  Even thought it was pitched less than a day ago, the yeast is very active and was climbing up the blow-off tube just 5 mins after it was attached:

Friday, 21 September 2012

Top Cropping Yeast

Top cropping is a useful way to harvest clean, fresh and healthy yeast, it's done while the yeast is actively fermenting and it's best pitched immediately into a new batch of beer.

When working with yeast, it's best to be as sanitary/sterile as possible.  Chemical sanitizers (like Starsan) are useful, but using heat to sanitize should be better again.
The only equipment needed to top crop yeast is a suitable spoon and container for the yeast.  An all-stainless ($2 Asian soup-serving) spoon and pyrex jug work well, and can be heat-sanitized (in boiling water for 15mins).

While the actual top cropping procedure is deceptively simple, it does require a few things to 'go right' before it can be attempted.

Firstly you need to be working with a yeast that allows top cropping; during the active fermentation phase, the yeast will float on-top of the wort with a sizable, active, 'rocky' type head.  The yeast (most often top-fermenting Ale strains), wort, temperature and other factors will determine if top cropping is possible (sometimes it may even be possible to top-crop a bottom-fermenting lager strain).
(Krasuen started forming within a few hours of the yeast being pitched, after about 16 hours, the fermentor was shaken in order to better aerate the wort, this likely made the yeast 'cleaner' than it would have been otherwise.)

The trick to successful top cropping is getting the timing right, you want to top crop the yeast when it's most active, when there is a large amount of healthy fresh yeast floating on-top of the wort, usually this time is called 'high krausen'.  In some situations this might be over a 2 or 3 day period, in other cases it might be a matter only just hours, attempting to top crop to early or too late will not work if there is not sufficient yeast to harvest.

Wyeast suggest that yeast can be harvested after the OG has dropped by 50%, however this might involve more constant gravity measurement than most home brewers perform.

As can be seen in both the photos above, two days after pitching, the yeast (Wyeast London Ale III, Wy1318) is forming a raft 70-100mm in height above the wort with a nice rocky/solid/yeasty head, making it the ideal time to harvest the yeast by top cropping.  However, the exact time when yeast can be top-cropped depends on many individual factors and there is no generic rule that can be followed, the fermenting beer must be checked periodically and top cropped when the yeast is ready.

Top cropping is only possible when using a fermenting vessel that allows access to the surface-yeast, top cropping with enclosed fermentors is not usually possible.

Using the sanitized spoon, first skim-off (and discard) any trub/break/protein or hop debris that sometimes floats on top of the yeast:

Then scoop up the fresh, clean yeast:

Continue the process to harvest enough yeast as required:

Since we have harvested only clean, fresh and 'pure' yeast, somewhere about 50-150ml should be adequate for pitching into a standard sized batch of fresh wort:

Depending on the conditions and time the yeast is harvested, it's possible that the yeast can be top-cropped again later (sometimes it will take only hours for the yeast to be ready for additional harvesting):
Photo taken a short time after the top cropping shown above.

Top cropped yeast, harvested at high krausen is fresh, healthy and active, so it's best to pitched immediately into a new batch of fresh similar composition wort, where it will likely 'kick off' very quickly.  If you are not able to use freshly top cropped yeast, it might be better to wait and harvest the yeast after fermentation has completed and the yeast has settled.

Wednesday, 19 September 2012

Brew Day: Brewlywed Bitter

The first of three "traditional English Ales" that I'll be brewing for my sister's wedding next month.

The recipe is a slightly adapted version of the Boddingtons Bitter found in the Brew Your Own British Real Ale book.  Gravity slightly increased (aiming for 1.038 but got 1.040), adjusted the hops to retain the balance (and for what was in stock) and used malted wheat in place of the white sugar (which should help with the expected 'creaminess').
Brewlywed Bitter
Style: English Bitter
Batch Size: 24.00 L
Boil Size: 32.93 L
Estimated OG: 1.038 SG
Estimated IBU: 32.9 IBU
Estimated Color: 6.6 SRM
Boil Time: 90 Minutes
Brewhouse Efficiency: Expected 75.0 %, Achieved 80%

3.50 kg       Pale Malt, Maris Otter (Thomas Fawcett)
0.25 kg       Crystal Malt - (Simpsons)
0.15 kg       Wheat Malt, Pale (Best Malz)

30.00 gm  Goldings (HG 12) [4.50%]  (90 min)  15.1 IBU
8.00 gm  Magnum (11) [12.20%]  (90 min)  12.2 IBU
6.00 gm  Fuggles [5.60%]  (90 min)  3.9 IBU
14.00 gm  Fuggles [5.60%]  (10 min)  1.8 IBU

5.50 gm       Calcium Chloride (Mash)            
10.00 gm      Calcium Sulfate (Mash)
1.00 gm       Yeast Nutrient (Boil 10 min)
3.60 gm       Brewbrite (Polyclar) (Boil 10 min)
                 
London Ale III (Wyeast Labs #1318) (1.5L Starter)

Mash Schedule: Medium-Light Body, HERMS Step Mash
Total Grain Weight: 3.90 kg
Mash In, Protien Rest  Add 15.00L, rest @ 55.0 C  5 min
Maltase Rest  63.0 C  45 min
Dextrinization Rest  71.0 C  35 min
Mash Out  78.0 C  10 min
Fly sparge, 21L water @ 80C

Yeast for this beer was the 1.5L starter from the 'split' yeast pack as outlined in my Splitting Liquid Yeast Packs guide.

The obligatory weighing-the-grains photo:

In an effort to refine the efficiency from my new system, I adjusted the roller-gap on my mill from 1mm to 0.8mm.

As expected, there was noticeably more fine flour.

But the DIY Perforated Stainless false bottom had no problem filtering the mash (could likely grind the grain finer if required).
The grain bed appears uniform and there was no noticeable internal-channeling, however (as can been seen in the photograph above) the fine-flower did form a bit of a solid layer on top of the grain bed possibly causing some channeling down the sides of the mash tun.  In the future I'll stir the mash some more to 'cut up' the top layer of the mash-bed to help ensure that the recirculated wort washes all of the grain.

Overall brew house efficiency was 80% which is an increase from about 70-75% from the last few brews on the new equipment, so the adjustment should be worthwhile.

The New HERMS Vessel in action:

First runnings from the mash into the kettle:
When fly sparging the flow should not be too quick, so the jug measures the flow so it can be adjusted to between 0.5 and 1L per min.

The last runnings from the mash (approx 3L) were collected to be used as the basis of the starter for the next yeast (Brewlab F40) that I'm growing up:

Due to the low gravity of the last runnings, additional malt-sugar (from an old tin-of-goo) will be needed to get the gravity of the starter to about 1.035 - 1.040.

Lots of home grown Golding, some Magnum pellets and specifically purhased for the wedding beers, some UK Fuggle plugs:

Hops into the kettle at the start of a 90min boil:

It was only the first (or second) time that I recall using UK grown hop plugs, and when cleaning the kettle after the boil, I was surprised to find hop seeds all over the place:

Given that there is no bitterness in the seeds, there was really quite a lot of them from the smallish amount of Fuggle hop plugs used, there are no male plants to pollinate my home grown hops and no seeds in hop pellets so no seeds in those.

I'm finding it's a good habit to clean-as-I-brew, so here is the mash tun clean, empty and recirculating cleaning solution through the HERMS coil ... still with about 45mins of boil time to go:

Collected almost the exact amount of wort in the fermentor (24.5L) with the adjusted efficiency resulting in 1.040 rather than the planned 1.038OG (1.036 in the recipe).

Using an aquarium air-pump, DIY cotton-wool and sample-vial filter to aerate the wort:

The air-pump was not really strong enough to work well with the stainless air-stone I have, so I just put the end of the air-line in the wort and relied on the surface-exchange of oxygen to help aerate the word - and still shook it around a fair bit when the yeast was pitched.

After pitching the yeast, and shaking the fermentor, cling wrap replaces the lid:

Held on with the lid's rubber gasket:

The next day the yeast had started to form a krasuen:
To ensure the wort was well oxygenated, I shook the fermentor up some more at this time.

The fermenting fridge is still full of lagering lagers, so I'll have to remove and keg them before the fridge can be used to ferment this beer.  Luckily the temperature inside the house for the last few days has been very stable between 18-20degC so I've not had to empty the fridge yet, but the beer is fermenting happily.

A couple of days after pitching, the yeast had formed a large solid krasuen, that was ideal for top cropping.
So this beer was used to take the pictures in my Top Cropping Yeast guide.

Saturday, 15 September 2012

Splitting liquid yeast packs


Splitting liquid yeast packs is an easy and cost-effective way to split, share and save yeast, saving money and making more yeast-strains available to try.  The information here is my take on the technique made popular by AHB forum member Tony some years ago, (see here and here).

This technique is something I've wanted to explain and photograph, but it's taken me a while (years) - since I have many yeast strains stored on slants or frozen - I don't often purchase liquid yeast.  However, since I'm about to brew some English Ales for my sister's wedding I wanted to ensure they were as close to the original as possible, so that was a good excuse to buy some liquid yeast.

The process here works for either Wyeast smack-packs or White Labs vials, but unfortunately, there are no local shops that sell White Labs vials so (unless White Labs or someone sends me a sample vial to take photos of) it's not likely to be something that I'll do in a hurry and hence why the photos below feature a Wyeast pack.

Advantages of splitting yeast packs (this way):

  • Simple and easy.
  • Minimal cost or equipment outlay.
  • Saved yeast is 'virgin' or 'generation 0' (hence should not be contaminated or contain mutations).
  • A store-purchased packet of yeast can be used for multiple batches of beer.
  • Stored 'splits' take up very little room.
  • 'Splits' are easily swapped and shared with others.

Disadvantages of splitting yeast packs (this way):

  • Minimal cost for equipment (vials, test-tubes or sample-jars).
  • Starters are required since the yeast-pack is split multiple times.

Equipment required:
The only specialty equipment required (compared to using a full yeast-pack) are some vials to store the 'split' yeast in (see note below for more details).

Step 0: (optional)
If using a Wyeast pack (as per the pictures here), smack the pack and wait for it to swell, this provides more liquid to split and 'revives' the yeast which should mean it will be viable for a longer period when stored.

Step 1:
Sterilize the sample containers, if they are supplied sterile ensure that the caps are not opened until you are about to use them.  If re-using vials, an autoclave/pressure cooker is the best way to sterilize them, otherwise try the Tyndallization process or simply boiling them for 10-15mins.

Step 2:
Working in your draught-free, clean and sterile as possible yeast 'laboratory', wipe the yeast-pack and scissors with alcohol and carefully snip the top-corner of the pack.


Step 3:
Pinch the snipped-corner to form a funnel and carefully decant the yeast-liquid into the sterile vials.


Step 4:
The size and number of 'splits' you make depends on the package size (see note below), how fresh the pack is, how many samples you want to save/swap, and the size of your vials.  Here I am making 4x 12ml 'splits'.

Step 5:
Label the vials (and optionally seal the caps using parafilm/tape).

Step 6:
Store 'split' samples of yeast as cold as possible in the fridge (but do not freeze it), after a short time the yeast will settle.

Step 7:
Swapping yeast 'splits' with other brewers allows you to obtain and use other yeast-strains to use without additional expense.
('Splits' stored in 10, 12 and 30ml vials)

This technique works equally well for any yeast supplied in liquid form.
WhiteLabs vials should contain about 35ml of liquid and 100billion cells, so it might be useful to add some sterile distilled (or at least boiled) water depending on the size vials that are being used.
Wyeast Activator packs (shown in pictures here) should have about 100billion cells in 125ml of liquid.
Wyeast Propegator packs should have about 50ml of liquid and 25billion cells.
In theory small samples of dry-yeast can be split, saved and propagated, however most people do not consider such a technique cost or effort effective and so it's generally suggested that the 'correct' amount of dry yeast is used.

Note about vials, sample-jars or test-tubes
Most people use laboratory-type sample containers, vials or test-tubes but most any container of suitable size and material can be used.  Vials made from autoclavable polypropylene means that they can be heat re-steralized and re-used.  I like to use the 15ml test-tube type containers shown above, but any vial/test-tube/sample-container from about 7ml up to 30 or even 50ml can be used.

To determine the number of yeast-cells in the split and remaining in the pack
First estimate calculate the number of viable yeast cells based on manufacture date (via MrMalty calculator).
Divide this number according to the volume of your splits and yeast-pack type.
Eg: My 1 month old Activator pack should have about 75billion viable yeast cells in 125ml of liquid, hence the 12ml 'splits' should have about 7.5billion cells each, and the remaining 80ml should contain about 48billion cells.  The 48billion cells remaining in the pack is more than enough to pitch directly into a 'full size' starter.

Storing 'splits'
Yeast 'splits' should be stored in the fridge at as cold temperature as possible (but not frozen) and should be viable for at least 6 and up to 12 months.  In theory it should be possible to replace some/most of the wort/nutrient liquid with sterile-glycerin and freeze the 'split', which should (in theory) greatly prolong the storage time (by years) - however I've not tested this theory yet.

Using 'splits' and split-packs
Due to the smaller number of yeast cells, a starter will always ]be required to grow enough yeast to ferment a (standard volume, standard gravity) full batch of beer.  In the example shown in the photos here, I guessed/estimated that (after taking the 4x 12ml splits) I have about 80ml liquid and 48billion cells remaining in the pack.  This is enough to pitch directly into a 'full size' 1.5L starter to produce somewhere around 150billion cells, which will then be pitched into 24L of 1.038 English Ale:

When using the yeast from the saved 'splits', the only time it would be recommended to pitch the 'split' directly into a full volume starter is if they are are larger-volume (30-50ml) and very fresh.

If the saved 'splits' are smaller in volume (like my 12ml 'splits' shown here) or older (more than 1 month old) a stepped-starter would be recommended in order to grow pitchable quantities of yeast.  The size and number of steps required will depend on how much viable yeast is estimated to remain, which in-turn depends on the volume and age of the 'split'.

Essentially what this yeast splitting technique is doing is swapping buying more/new/fresh yeast-packs for making (stepped) starters, so a good understanding of starters and stepped-starters is required before attempting this technique - however there is no reason anyone could not 'split' the first (and every) liquid yeast-pack that they buy.

After splitting the 4x12ml vials and the remaining (approx 80ml) yeast-slurry was pitched into a 1.5L starter, which was grown on the stir-plate for a 36h then left to ferment/settle for 12h.

The gravity is about 1.005, it smells/tastes like it should and visually there is a good amount of yeast ([i]somewhere around 150billion cells +/- 50%[/i]) so it should be ready to be pitched (tomorrow) into a 24L batch of 1.038 English Ale.
... the splits are in the fridge ready for future use or swapping.