Mash & wort for yeast propogation

[Fore]

I'm about to do a mash solely for the purpose of creating wort I'll later use to propagate yeast. It's much cheaper than using powdered malt extract.

I thought I'd just run my plan by you in case I plan something daft.

I believe best gravity for yeast propagation is in the region of 1.020 to 1.040. As I'll be freezing this and have limited freezer space, I plan to create as concentrated a wort as possible, and then dilute it down just before use. My thought is to keep initial run off separate, the concentrated part, then start a batch sparge, testing the gravity and adding sparge water until the batch reaches 1.030. So I'll have one part ready to go as is, and another part in concentrated form. A good plan? Any better idea?

So there is a lot of information on correct gravity, but what about mash temp, grain, and possibly even minerals?

Mash temp: I'm thinking we want to give the yeast easy access to the sugars, with not so much sugar carry over to the main brew. So I'm thinking a very low mash temp, say 62 degrees.
Grain: To carry the least flavour possible into the main brew, I'm thinking Pils.
Minerals: As this is a real mash, I guess I have to do what I normally do for a real brew, i.e. reduce carbonate so as to fall to an acceptable mash pH, and add calcium for yeast health.

Sound reasonable?

 

[Leon103]

Don't really know the answer, but to me that seems a lot of work and time for such a small saving

 

[Fil]

i would consider an overnight mash starting @ 66C that way you should start converting complex sugars in prep for the alpha amalayse to chop down further when the mash cools a little overnight. aim for a 1.040 target 1.020 is way too low imho (all ive done tho is read the chris white yeast book and forgotten more than i recall)

the problem using dme is unless its a usual brewday ingredient its difficult to maintain dry and often when returning 6weeks later its to be found as a wet lump even when stored in expensive 'air tight' storage boxes.

how about using jars of health food shop malt extract for your starter food??

 

[Fore]

Don't really know the answer, but to me that seems a lot of work and time for such a small saving

I think when you've decided to propagate yeast, the time is mostly in that activity, not a mash that will last me through many propagations. Of course I've not done it yet, but the more I formulate the plan, the more simple the mash part seems. For example, I can mash indoors because I don't need the 3 tier steps I need for the boiler and fermenter. It's just a case of dropping malt & water in my mash tun and leaving it for more than 1h. Not much more to it really. And I calculated the cost in making up from extract, and it's not cheap, particularly if you intend a 2 step build up. It wouldn't bankrupt me of course, but the cost of propagating a dry yeast packet to twice the number of cells, is about the same as the cost of a yeast packet. While the comparable cost of grain is so negligible as to be almost free.

 

[Fore]

i would consider an overnight mash starting @ 66C that way you should start converting complex sugars in prep for the alpha amalayse to chop down further when the mash cools a little overnight. aim for a 1.040 target 1.020 is way too low imho (all ive done tho is read the chris white yeast book and forgotten more than i recall)

the problem using dme is unless its a usual brewday ingredient its difficult to maintain dry and often when returning 6weeks later its to be found as a wet lump even when stored in expensive 'air tight' storage boxes.

how about using jars of health food shop malt extract for your starter food??

OK, good idea. 66C and left overnight it is.

You mention 1.040 as a target. That being a final target, so my idea of making up a concentrated form, then diluting down, is OK?

I quite like messing about with my equipment :whistle: and I'm OK to do one single mash that will probably last me more than 6 months. It just seems daft to me to buy an extract of something I can easily make myself. Yet I seem the odd one out, as all write-ups seem to use extract.

 

[strange-steve]

What I was doing for a while was, when brewing a batch, adjusting the recipe to allow for an extra liter or so of wort in the pre-boil volume. Then as the boil was reached, I would take that liter just before the hops were added, and stick it in a bottle which would then go in the fridge or freezer to be used for the next brew's starter.

 

[Fore]

What I was doing for a while was, when brewing a batch, adjusting the recipe to allow for an extra liter or so of wort in the pre-boil volume. Then as the boil was reached, I would take that liter just before the hops were added, and stick it in a bottle which would then go in the fridge or freezer to be used for the next brew's starter.

Oh bloody hell, why didn't I think of that

My next brew doesn't need me to propagate yeast, but the one after does (I bought the packs expecting I would be up and running by then). So I'll just create X litres more wort than I need in the next brew, then freeze it up.

The disadvantage of that approach is I can't really create the concentrated wort I wanted, as to calculate the SG of what remains would be pretty tough, if not impossible. Still, it means there is no extra work at all in the process. And it occurs to me I don't need to be so accurate on my 'volume to boiler' calculations, as I just take out everything other than what I need for the brew.

"What I was doing for a while". Can I assume you reverted to buying extract? Simplicity won out?

 

[strange-steve]

"What I was doing for a while". Can I assume you reverted to buying extract? Simplicity won out?

Sort of, I recently got a Grainfather and I'm keeping it straight forward until I'm fully comfortable with using it, then I'll get back to it

 

[BeerCat]

I have done that before to make a starter and it was a proper pita and took ages. Am gonna get 3kg of spray malt as only works out 50p for a liter starter. Failing that i would do as others have said and go down Holland and Barret.

 

[MyQul]

I've thought about doing this but I usually buy malt extract from holland & barrett and they often have a buy one get one free offer on so it's quite cheap to use that.
But tbh, I wonder if your over complicating things. The concentrated idea is a good one but worrying about mash temp and minerals, I'm not so sure. Mash temp - Depending on what yeast you use you probably dont need to worry about this too much unless your catering for a specific strain. Minerals - just add some yeast nutrient to the starter when you add the yeast.

@leon103 it doesnt have to be much work at all. Mash - most of the conversion is done in 10 mins or so, so you can just mash for 15 mins. I've done plenty of 30 min mash stove toppers and cant tell the difference between a 30 min mash beer and a 60 min mash beer. Boil -you making starter wort not beer and only sterilizing the wort, so you really only need to boil it for 15 mins at most as your not isomerising any hops or stabilizing the wort for long packaging periods

 

[Fore]

I've thought about doing this but I usually buy malt extract from holland & barrett and they often have a buy one get one free offer on so it's quite cheap to use that.
But tbh, I wonder if your over complicating things. The concentrated idea is a good one but worrying about mash temp and minerals, I'm not so sure. Mash temp - Depending on what yeast you use you probably don't need to worry about this too much unless your catering for a specific strain. Minerals - just add some yeast nutrient to the starter when you add the yeast.

OK cheers. Don't think they have a Holland & Barrett in France; it's a challenge to get hold of grain to be honest. But point noted, it doesn't need to be a brew store bought extract. I'll keep my eyes open.

About over complicating...just asking. Not really figured out yet whether these issues really matter or not.

But if you are going to do it, may as well plan and do it the best way with advice sought. For now, the over-production of a normal brew day mash seems the best idea. I think I once read that same idea somewhere (probably here), but then I already had my next brew water volumes & additions calculated and recorded, so delayed and then forgot the idea.