I presently have the capability to ferment 20 gallons in one fermenter. But my brewstand will do 10 gallons in a session. I want to ferment all 20 gallons in the same vessel. My plan is to brew 10 gallons on Saturday and pitch the starter I have going right now. Then on Sunday brew my second 10 gallons and pump that into the already fermenting batch. Aside from potential risk of infection (I am pretty surgical with my clean-up, prep, and sanitizing but that doesn’t rule it out as potential factor.)does anyone see any potential flaws or have any advice for this endeavor? I have a 2000ml starter of S-05 which has been very successful in my past 10 gallon bathes for this brew. Also i am using a Brutus build for my brewing, not sure if this necessary information. Thanks in advance.
nope - sounds like you will be just fine - hopefully the first part will be just reaching krausen.
A lot of smaller breweries do exactly what you plan. my local brewery is a 15bbl system, but they have several 30bbl fermentors.
BTW, i know you said you’ve been successful with it in the past, but making starters with dry yeast isn’t so good for the yeast. and at ~$3 per sachet, you aren’t really saving much by doing it if you’re using DME. just saying…
do you have a way to oxegenate/aerate the second batch on it’s way to the fermenter? that’s the only problem I see. when breweries double batch into one fermenter they have an inline o2 setup so the wort is getting hit with o2 as it enters the fermenter.
also, you don’t specifiy how big your fermenter actually is but if it’s like a 22 gallon you don’t really have enough space to ferment 20 gallons of wort as it will take a fair amount of headspace
good point jonathan about aeration - forgot about that - they do aerate in line. perhaps, if he chills in the kettle (Immersion chiller) he could aerate prior to running off, although that would likely stir up the previously settled trub.
not sure on the headspace - 22gal for 20 wort would be close…
The fermenter is 23 gallons, i had figured this would be fairly under undersized for the size of the batch. But I should end up with a bit under 10 gallons with each, it’s definitely going to be close. I don’t have aeration set-up but I do pump in from the top of the fermenter, suspending the hose over the liquid. I know it’s not ideal for getting enough O2 in to the batch. But this is what i have to work with right now.
Blatz,
Could you enlighten me a bit on your statement about starters not working well with dry yeast? I have no problem adjusting my process, just need looking for a little more insight.
And thank you both for the feedback.
The ROT I have heard is 30% headspace. might be okay with ~10-15 though.
on the dry yeast, the manufacturers prepare the yeast by loading it will all the reserves of nutrients it needs to wake up and get to work. by adding the yeast to s small volume starter it causes them to wake up and use those reserves, but there isn’t enough food there to rebuild and be ready for another growth phase so you end up with a few more much less healthy cells than had you just rehydrated and pitched.

Blatz,
Could you enlighten me a bit on your statement about starters not working well with dry yeast? I have no problem adjusting my process, just need looking for a little more insight.
via the drying process, the manufacturer packs in nutrient reserves (glycogen?) in the cells. when you make a starter, the yeast release these reserves and apparently become somewhat weaker.
but its also time and economics - a for an average 10gal batch of ale, you need 2 packs of US-05. if you’re going to use a starter, you’ll need a 2L starter on a stir plate to grow the one pack to the size you’ll need for the pitch. 2L means you’ll need about a half pound of DME, northernbrewer.com sells DME for $5.79 per pound so about $2.90 in DME. They also sell US-05 for $3.29. Which would you do?
I had no idea about the manufacturing process for the yeast. This definitely makes sense to me. So that being said, if I’m understanding correctly, dry yeast is really generally intended for a direct pitch?
If you are doing a double batch you want to pitch enough yeast for both batches in the first batch and only aerate the first batch.
It is no problem to wait until the next day, but it is actually a lot quicker if you can just get the second mash going as soon as you are done draining the mash tun into the kettle for the first time. Everything is already preheated and it saves a little cleaning up time.
I was thinking about that also. Longer brew day but less chance for variation/problems doing it all in one day. Thanks again.