Fermentation

[MARMITE]

I have just started brewing again after many years and am a bit rusty! I've done 4 brews so far and am having difficulty getting the gravity down to reasonable levels. Info as follows:

1. Wheelers Wassail - OG 1066 - Pedigree yeast - 77% eff - 1019 current gravity after 38 days (still working very slowly in demi-johns).

2. Pedigree - OG 1046 - Pedigree yeast pitched from previous brew - 80% eff - 1011 current gravity after 5 days (had to prime in cask to induce condition).

3. Sarah Hughes Mild - OG 1069 - Pedigree yeast from previous brew - 91% eff - 1022 current gravity after 20 days (still working very slow).

4. Everards Old Original - OG 1061 - Safale 4 yeast - 84% eff - 1019 current gravity after 12 days.

Note: Last 2 brews stronger than recipes due to better mash efficiency than recipes.
As you can see the only one which fermented out fast was the Pedigree. What am I doing wrong and when is it safe to bottle.

[ColinKeb]

have they all been stored in the same place?

[MARMITE]

The first 2 brews were initially stored in the kitchen where the temperature could have dropped to 12C. For last 14 days all brews have been stored in a purpose built cabinet with heater and thermostat, where the temperature is maintained at 20C. The Old Original with the Safale used has always been kept at 20C.

[Aleman]

In an ideal world You should not reuse a yeast that has been pitched into a wort much greater than 1.060, they have worked hard and are bloody knackered! Ok you got away with it from brew 1 to 2, but consistently reusing a yeast that is not performing leads to beers that do not turn out as well as they could do.

When I'm brewing a big beer, I tend to make a 5 Gallon batch at 1.038-1.040, pitch a 1L starter into that, when its finished, Rack the beer off, Wash the yeast, pitch a new qty of wort and aerate for 25 hours before pitching into the main batch.

[MARMITE]

Many thanks for your replies -

3 further questions:
1. When is it safe to bottle these brews?
2. How do you wash yeast?
3. I brewed these high gravity ales taking GW's advice with the intention of preserving the yeast strain for future brews. He recommends 1065+ (see page 61 Home Brewing The Camra Guide). Do you disagree?

[Dan]

Heres my 2penny rant on repitching and yeast washing

yeast washing is a debated subject. It wont kill wild yeast and It doesnt fully eliminate all bacteria and depending on the strain can alter the beheviour in the subsiquent fermentation cycle. Plus you usualy have to pitch a pile of phosphoric acid in your wort. dragging the Ph down.

heres brupaks lowdown on the method if you fancy tring itclicky

I regularly repitch slurry with no washing at all. If you can leave all the break material behind in the boiler and try your best not introduce excessive levels of bacteria and wild yeast there wont be much need for washing. I reuse the slurry up to 3 times on a regular basis. after that Its cheap enough to reculture from a new source

Personally I dont repitch yeasts from brews as high as 1.060
its like dumping slack and knackered grannies into a marathon and when they die the spill their guts into your nice clean wort. You then play "name the taint"

imagine youre a yeast. floating happily in a jar of sugar water reproducing and doing what yeast do. then some one shoves you into a can of lyles choaking syrup. first the super high osmotic presure outside wants to rip through your cell membrane. then comes the high alcohol making your environment even more hostile. if your lucky, you come out of it withered, half dead and surrounded by dead cells.

the flip side is dont havest yeast from a weak wort.
1.040 -1.050 is excellent

[Aleman]

3 further questions:
1. When is it safe to bottle these brews?

I would say that it is safe to bottle them now, without knowing at what temperature they were mashed and the amount of crystal and dark malts in them it can be difficult to predict what the terminal gravity will be. Although you say they are slowly working, this could simply be CO2 coming out of solution causing the airlock to bubble. The general consensus about bottling is to take three gravity readings a day or so apart and if it is the same then you bottle.

2. How do you wash yeast?

I wasn't talking about acid washing, which I've dome but is very tricky to do properly. All I do is once I've siphoned the beer out of the FV I add a litre or so of Cooled Boiled Distilled Water to the FV and shake it around to loosen up the yeast. The slurry then gets poured into a large sterilised vessel holding another litre or so of CBDW. This gets shaken swirled every 30 minutes or so for 2 hours. The trub and dead yeast form a brown layer on the bottom of the flask the 'healthy' yeast stay in suspension longer. After a couple of hours I pour the yeast into another sterile vessel and let it settle out for a day or so before pouring off the cloudy liquid as that is the less flocculant yeast and I don't want to select for yeast that doesn't settle out. I then add my starter wort to the settled yeast ready for the next batch.

3. I brewed these high gravity ales taking GW's advice with the intention of preserving the yeast strain for future brews. He recommends 1065+,Do you disagree?

No, I've used GW's method myself in the past . . . but the important thing to remember is that you only want to preserve yeast that have performed a healthy fermentation. I wouldn't bother trying to save a dry yeast as it is more certain to buy another packet, and its a minimal cost.

Personally I would be tempted to use Daabs/Jims method of preserving yeast, for a brewing season and start again the next season with a new yeast culture. I use Aseptic methods of yeast farming now, culturing up from single cells to 500ml of yeast for pitching. I find this produces a much more reliable and healthy fermentation.

[skinfull]

Hi ya. Are your figures for the efficiency taken from the mash efficiency or the brewhouse efficiency.