It would appear my maths does suck..... <_<
Right, lets knock that back to 2-2.5kg of grain, I see I failed to actually link to the recipe I referred to, I am gifted....
Right, so lets say I want to follow
this recipe for my first partial, butters, you numbers guru you, how would you suggest adjusting the numbers to make it work?
Gavo is right with what he's saying, for sure. There are a few ways that it can be done, basically, as gavo said, replace the jw trad ale with enough ldme to up the grav to the same amount. For me, I would make it an even 2kg of ldme, and reduce the trad ale down to 1.2kg. (edit - this would give 2.6kg of grain, which you should be able to do on the equipment discussed). I personally wouldn't go further down on the JW trad; if I wanted to reduce the grain further, I would start replacing some of he wheat with dry wheat malt, so that from a grain perspective, the trad ale is equal or greater than the wheat grain.
Sorry to interrupt again buut this seems as good a thread as any to chime in..... so to get this straight, for every kilogram of grain used by the method discussed, you would yield 700 grams of fermentable malt equilavlent to the same character of LDME ? That seems a high figure, as I would have thought the dry weight of grain would be measure least half of unwanted husks and other fibrous matter.......
And if all-grain is the goal for Pollux with his 15l pot capacity, why not do two batches back to back then add the results of both to the one fermenter ?
jase, you can do 2 batches side by side,, and then blend into the fermenter; particularly if it was no chilled and hotpacked. But you would need to do the 2 mashes seperately. If you do a mash, and have more than you can boil, then the left over that is waiting around starts to run into issues with continued enzyme activity, and the risk of infection increases (although for me, its the continuation of the enzyme in the liquor that is the bigger problem of the two.) There was a thread about not mashing straight after the boil in the AG threads recently. Leaving it just long enough to do back to back boils isn't that much of an issue, but it is something that needs to be considered.
With the grains yield, all grains have different yield potential, and there are various scales for this. But basically, the grain weight is mainly the endosperm, the husks weigh next to nothing. The actual yield depends on 2 factors. The potential, and the efficiency. For the trad ale, the potential is 80%, and at 75% efficiency, the yield would be potential x efficiency x weight which is 0.6 kg
extract weight per kg of grain. This is not to be confused with the weight of extract, extract weight refers to the weight of the actual fermentable. 1kg of ldme has an extract weight of 920-970g (depending on manufacturer and processes used) because even 'dry' extract has a proportion of water and other non fermentables in it. If interested, have a read of Palmers how to brew (I think its chapter 12), where he discusses potentials for various grains, and how to calculate gravities manually from that.
If I;m not careful, some of you buggers are going to come over to the dark side :lol:
Edit: if your efficiency is lower, it just means that you will be short on gravity...you have 3 options there. 1/ add more ldme to bring the gravity back up. 2/reduce the volume (by not adding as much water into the fermenter at the end), thereby bringing the grav back up, and adjust your hop weights to give you the same IBU for the new volume, or 3/ go with the slightly lower grav, and reduce the IBU to keep it in the same BU:GU ratio. IBU/OG = BUGU, and in this case it is 69%. So the IBU required would be 69% of the OG.
Really don't like the idea of holding the temp for an hour on the stove top.
