A Little Technical…
I’m in the thick of things right now, right around the fifth batch on the big system. In a prior post I referred to the first full-blow scaleup of the ‘Rubber City Red’ as a ‘comfort cruise’. Every batch after that bore no resemblance to that remark. Idiot that I am, I should have never even thought it. You see, the Rubber City Red has a low amount of hops and a lower amount of alcohol (grain)…the whole process was just easier.
Hoppy Beer Problems
The second batch, my Amarillo IPA, was not without major problems on the scaleup requiring me to rethink and retool some of my plumbing and processes. The Amarillo IPA has a lot of hops. A LOT. These clogged and slowed my pumpout adding additional bitterness that I didn’t want. The hopback I was using was open (instead of closed) this time to hold the larger amount of hops – bad idea, this caused too much oxidation (nasty hop taste). After finally getting the wort into the fermentor, I added the yeast. Everything seems to go well for the first two days and then the fermentation stopped prematurely. I smelled and tasted the beer. This tasted familiar…familiar like the only three homebrew batches that I put down the drain without ever knowing what went wrong. Well now that this is a 90 gallon batch that I’m putting down the drain, I better figure out what-in-the-world went wrong! The prematurely stopped fermentation had nothing to do with the hops…the yeast were unhappy. You see, scaling up I had to start yeast farming – something which I never did on the homebrew level. I initially thought that I screwed this up.
I’m a Yeast Farmer!
On the homebrew level, you can ‘get away’ with buying a pack of yeast at your homebrew store, add it to you’re wort and voila! You have beer in a few weeks. Scaling up 6x, I wasn’t going to buy six of these per batch ($). And in retrospect, I was adding the ‘minimum’ amount of yeast anyways. On the homebrew level of 15 gallons I was in this ‘grey area’ that I got away with most of the time.
To successfully give 60-90 gallons of beer enough yeast, I had to farm them from one pack, to a 2L flask, then again to a 5L flask over several days. Not a problem. But you definitely don’t want to do this everytime you make a big batch. What you can do, and what most brewers do, is take yeast from a prior batch and use it for the next batch – repitching. This is what I did. I harvested yeast from the first batch of the Rubber City Red and added part of it to this Amarillo IPA. When the beer stopped on day three, I thought I screwed this part up somehow and got the math wrong regarding how much to use and severely underpitched (not enough yeast).
That wasn’t it. I used exactly the amount of yeast I needed. What I found out is that I could have oxygen depletion in the fermentor in the first few days (boiling a liquid, in this case, wort, strips all gases out of it). This is a hot topic on probrewer.com. Many skilled homebrewers add oxygen when they add it to the fermentor. Yeast love oxygen – but only in the first day or two. They need oxygen to multiply to then get to work on converting sugar to alcohol. I never did this on the small scale level and got away with it just due to the surface area to volume ratio of the fermentor – enough oxygen was able to get back in a lot easier compared to a 6x larger fermentor as you are able to ‘splash’ the cooled wort back into your little fermentor allowing the air to mix back in. Not so on a completely sealed large fermentor. Most probrewers just add a bunch of oxygen – though surprisingly without testing and verifying it. And the flowrate of oxygen is critical too…you don’t want too much. I wanted to see exactly the amount of oxygen in the fermentor before I messed with oxygen injection. I found a dissolved oxygen meter on Amazon with a decent reputation. I was going to scaleup the ‘Towpath’n Pale Ale’ next and this would be a good test. But if my dissolved oxygen numbers were too low, what was I going to do? Blow bubbles in it with a giant straw? What I did was get a space-age crackpipe.
You see, I didn’t want to mess with renting an oxygen tank, figuring out flowrates, oxygen bubblers and what-not. What one can do is inject regular, filtered air via a venturi into the wort and it will give a perfect level of oxygen – a method that few brewers do. The added benefit with using air is that you can’t over-oxygenate the wort. GWKent had a venturi so I got it for my brew weekend.
Venturi’s suck air into the liquid stream via a pressure drop from a constriction in the pipe (an application of the Bernoulli effect). Remember the venturi’s that suck air in and blow it out in aquarium filter pumps? It’s the same principle. So I put my venturi right after the heat exchanger. No dice. No air got sucked in on the way to the fermentor. The flowrate was too low. So I had an ingenious idea, I put the venturi on a recirculation loop from a few ports on the fermentor. It worked (though I had to use a compressor to push it in) I took the dissolved oxygen from 1ppm to 8ppm in 30 minutes. Perfect. This just took an extra step from direct oxygen injection that most brewers use. But it was cheap as air is free.
O2 = Happy Yeast
This fermentation took off like a rocket. Never have I had a faster fermentation. I have to thank Rich T. from the Akron homebrew club, SAAZ. We had a discussion months before on all things yeast and I started tracking my fermentations daily – just to get some curves – to get a feel for the fermentation, mathematically. This was a totally different fermentation from those in the past. This fermentation made a better beer…faster. One scale-up problem solved.
Wort Heat Exchanger
Also with the Amarillo IPA, I realized that I just couldn’t keep using my little Therminator – the heat exchanger to cool beer down from boiling to about 70 degree fermentation temperature at the homebrew level. For hoppier beers with a lot of late addition hops for aroma, it’s critical to pump out fast so you don’t keep generating additional bitterness. This is where a lot of session IPA’s (and IPA’s overall), fail, in my opinion. My homebrew heat exchanger just couldn’t keep up with Akron’s rising water temperatures along with a quick pumpout on a much larger batch. Time to get a bigger one!
The first time I used this heat exchanger I totally clogged it with hops and it’s performance suffered. I’ve determined that my new boil kettle has the intake tube too far down into the cone of it – picking up too many hops. I wish it was further up. And this was only a minimally hopped beer. Imagine what this would look like on an IPA?
Before I discuss filtration, let me put out that I PREFER a filtered beer (or at least clear = aged) on most styles. I don’t want to chew my beer. Filtration is refinement. It doesn’t necessarily take away taste. Not filtering can add taste – like a yeasty taste…that isn’t necessarily good. Not filtering is EASY though. So easy. I do like that fact that when I brew a wheat beer, or certain IPA’s, that I don’t have to filter. Up until now.
Now that I’m filtering big batches, my little canister filters won’t cut it. I went down to West Virginia a few years back to get a 40×40 plate filter in expectation of this day. I ran one of my little 15 gallon batches through it soon after I got it just to test it. It seemed to work ok counter-pressure filtering. It had leaks though. I had the stainless tubing recently redone to combat some of the leaks. I tried a hack-job to fix the other one. It didn’t work. I drained half the beer I was filtering (though honestly, it didn’t look like that big of a leak).
I have some ideas to fix this.
More Complicated Plumbing
These pictures say it all…
Grains and hops
Being that I’m brewing larger batches and much more frequently, I had to get a wholesale account at the local LGCarslon supply store. As a homebrewer, I’ve used Grape and Granary for years. I could call up, place an order and within an hour, have my grains and hops ready for a double 15 gallon batch. You see, up until now, I didn’t really have to plan anything. Now I do – about two weeks in advance. Though LGCarlson is a good company, they deal in large orders that you just can’t ‘have in an hour’ – and they are a few times further away than G&G. Instead you can pick it up in several days. So now I’m using LGCarlson for the main grains and hops, but with a healthy dose of Grape and Granary on yeast and specialty grain for unplanned brew days…or issues that I just haven’t successfully planned for yet!
Thanks Grape and Granary for being my non-planning, need-it-the-last-minute crutch. You’re a great group of people. If I make it to a 15bbl system, I’ll still be placing a last minute order to you.
So those are some of the issues I have been dealing with the last month. NOT TO WORRY THOUGH! I have no reservations dumping bad beer and I’ll do it again if needed! I have figured out most of my scaleup issues now.
Any More Word on Opening, Ron?
There is still no word from the Summit County Building Department on some stuff I submitted three weeks ago regarding occupancy and being able to open. I plan to make some MORE phonecalls this week to see what the issue is. They haven’t answered ANY of my emails or voicemails for nearly a year. I’m not expecting anything different. I’m going to try Akron building planning first as they are a recent ‘satellite’ office in the Summit County Bldg. Department. I hope Akron cares about a new, small business trying to open before they run out of money from waiting on a local bureaucracy that just doesn’t return calls or email, repeatedly. I have a feeling that they are going to try to jam me on something that they could have cleared up a long time ago if they would just have some basic customer service and responded to one of my many inquiries on how the process works.
Wish me luck this week, I’m going to need it!