My Mongrel has been going for 4 days on a WLP-022 (Essex Ale) yeast cake, set to 18°C for the first 2 days, then 19°C for last 2.
Already down to
SG=1.014.
Tasting mighty fine.
Thinking i'll go down the (D)IPA path & hop the bejesus out of it.
I'll wait for the yeast to finish & drop a little first to get a better taste for it before deciding; but it's tasting more like an IPA base than an Old Ale.
... Though maybe i'll look at splitting some off & minikegging it with an EKG keg-hop when i transfer the majority to the 2nd FV for CC-ing & dry hopping.
PS: (
@laxation), this was drained straight onto the 022 yeast cake after it'd chewed through 3 previous beers.
I generally haven't worried about the overpitching thing as i do tend to slowly ascend in OG of the consecutive beers and i'm normally keen to the cleaner drier finish the consecutive full-cake pitches produce. The reasoning i adhere to is based on the idea that most of the flavour components from a yeast develop in the first 24hrs from the reproduction of the yeast, not from the actual fermentation phase itself. So if you want a lot of flavour from the yeast, it's best to under pitch (as Mofox mentioned). Similarly, if you want less, then a higher pitch is better. Also, stress can encourage the formation of flavour compounds, both good and bad, so other factors like temperature, nutrients, etc can come into play. So it can depend on whether you want lots, some, a little or no flavour impact from your yeast as to what is best in those parameters for each beer.
Given this is an English yeast and i'm keen to get a some flavour/aroma elements from it, i'd maybe consider a reduced yeast size &/or ferment a little higher in temp. OTOH, as this is a super strong beer, i generally find the treatment to get some esters going in a lower strength beer produces too much in a bigger beer - either there's too much ester production or simply in such a big beer the "regular" amount of esters become too cloying. So basically i decided i wanted a cleaner fermentation and the yeasties would still reproduce a little given the significant step up in OG, so i went with keeping the yeast cake as is & fermenting at 18°C. Which luckily coincided with my laziness to just think **** it and empty the cube straight onto it.
The other info i keep in mind is that i've read a few threads on here where some of the more experienced and respected brewers have stated they basically have never had problems with overpitching. Sorry, that's a pretty lame bit of evidence & justification, but i don't have it bookmarked, etc.
PPS: found this from my notes when a started brewing back in 2012, maybe it'll help someone:
Yeast Info
from video:
!
White Labs (Neva Parker presenting)
Lower pitching rate/amount = higher growth rate (ie: more proliferation/multiplying of yeast cells. Because the small # of cells need to multiply like crazy in the large wort mass, whereas a high pitch rate means there's already lots of cells, so less growth/proliferation is required)
So "Growth Rate" is the same as "proliferation rate"
Higher O2 levels => higher growth rate
Higher growth rate => higher level of metabolic activity overall in wort.
Higher Metabolic Activity => higher (yeast) flavour byproducts (esters, fusels)
Higher OG => higher metabolic byproducts (fusels, esters)
Higher temp => higher esters & fusels
Esters are produced via acetylCoA in the non-growth phase. AcetylCoA is used in growth, then when growth stops it diverted towards ester production.
Most flavour compounds are produced in the first 48hrs (after growth phase?). After that, the yeast is generally "cleaning up" diacetyls & acetylaldehydes, etc.
~8-10ppm O2 = optimum for yeast growth. Results in lower FG, better metabolic activity.
Can take ~20min w an airstone & aquarium air pump
So,
High pitching rate -> Low acetylaldehyde, low fusels, high esters
High O2 -> High acetylaldehyde, high fusels, low esters.
Under pitching = strong yeast flavour produced.
Over-pitching = v clean, reduced yeast flavour.
Nutrients
Nitrogen - generally not needed unless using many adjuncts. Can use DAP to give nitrogen
Zinc - Dead yeast or zinc sulfate. Zn is used in an enzyme to convert acetylaldehyde to ethanol. Can generally be important/insufficient***
Other Minerals - Mg, etc. Generally not needed
Neva's fav yeasts:
WL020 - amber ale yeast
Edinburgh? - v versatile
Platinum, 510 - Belgium strain, clean, low ester, tart acidic finish.
White Labs = 1.5-2 billion cells per vial.
EDIT: NB: ~10mins in Neva starts talking about those factors affecting yeast, ~18:30 she summarises these points and explains how acetylaldehyde, fusels and esters are affected.
FWIW, my explanation at the start is a little wrong - fusel and ester production is somewhat inversely related for pitching rate & O2.
