Calculating a higher starting gravity to liquor back

[laithclark]

This may sound a basic question but here goes. I run a small 1 BBBL brewery with a pretty small mash tun, meaning I max it out at 4% ABV to get my 165 Litre output post fermentation. What I would like some insight on is how I calculate to brew stronger beers, with more grains but then liquor back to reach my volume target. When I have done this before I fall short on volume to about 150/140 litres.

Any ideas you can give me would be much appreciated. Thanks in advance

[brewfun]

If you want to stay all grain, it's not unusual for brewhouses to yield lower volumes in trade for higher gravity. But 4% average is a sign of a very small mashtun, indeed. The most common systems I know of are build to yield 5% beer, most of the time. I hope you're getting high mash extraction from the grain you can use.

My first thought is to use Brewers Crystals or Malt extract to boost your kettle gravity.

Another thought is to do a reiterative mash, where you do two back to back mashes. The second mash gets the middle to last runnings of the first mash at dough in, which boost gravity significantly without too much volume.

My final thought is to ask why you can't just build a bigger mashtun? At 1 bbl, it's not too difficult or expensive. I happen to have a little side project of a 1 bbl pilot brewery, which uses a 150 qt (142 l) ice chest for the mashtun. Nothing fancy, just a slotted copper manifold on the bottom. I know I can fit about 90 to 100 lbs of grain in it, which should give me at least 9% beers.

[laithclark]

Hi there

Thanks for the thinking. The issue with the equipment is that its not mine, I rent the brewery on a per use basis otherwise I'd have a much bigger tun and a few other things besides.

I have thought about using ME to do the job but I'd rather stick with the grain solution and I get very good extraction rates with the kit its just limiting the wort output the more grain I use. I was just wondering if I use more grain to achieve say 4.5% ABV and then liquor back to say 4.2% then what is a good way to calculate that in advance of brewing rather than on the fly when I know what wort I have and OG.

Thanks
Laith

[Oginme]

Two things come to mind.  The first is to set up your equipment profile to top off with water into the fermenter.  This would set up the mash tun with less water than is needed and producing a higher OG wort to achieve your target ABV goal at the end of the process.  The second is to use the dilution tool and set up your recipe to produce the higher gravity wort from the onset. This is essentially doing a manual version of what the software can do in the first option, but it would be more representative of a dilution post fermentation and pre-packaging.  This is the way A-B in Merrimack, NH produces their NAIL brews; making a much higher alcohol batch and then diluting it in the packaging line to the desired level of alcohol.

[dtapke]

I'm curious of your setup. You must only be using a 20-30 gallon mash tun? I would think if this is your limiting factor that Brewfun hit the nail on the head: get a bigger mash tun. You should be able to acquire one of functional quality for a couple hundred bucks, or high quality for less than 1k.

Another option you could perhaps do is two no sparge mashes? I'd be curious to know where the hold up is thats preventing you from running a 9-10% beer through your system.

[Kevin58]

I'm curious of your setup. You must only be using a 20-30 gallon mash tun? I would think if this is your limiting factor that Brewfun hit the nail on the head: get a bigger mash tun. You should be able to acquire one of functional quality for a couple hundred bucks, or high quality for less than 1k.

Except that he already stated the equipment is not his. I think Brewfun's other suggestion of using malt extract or sugars to boost the gravity is the simplest solution. Commercial brewers have always used sugar in some form and for good reason. I know homebrewer's who have "gone all grain" often have an aversion to using extra sugars but you shouldn't. It works.

[dtapke]

Oh yeah there's absolutely nothing wrong with using sugars or ME! It's just a tad more expensive.

as far as equipment ownership, if he were to invest in his own mash tun and swap out when brewing on this other persons gear, then he's working towards building his own equipment which I can only assume would be an end goal.

The other obvious answer would be to just run a smaller batch.

Hard to tell whats going on without an approximate equipment profile and recipe though. I would think a "1bbl" brewhouse would be equipped with a properly sized 50-55ish gallon mash tun, capable of holding 100 lbs of grain or so and achieving 9-10%abv without much issue on a 35g batch, it seems maybe he's being a bit overzealous trying to get 45g of 9% beer out of a 1bbl brewhouse sticking with all grain concepts. you just can't.

but really to liquor back from my knowledge isn't to increase the abv, if anything its to increase production volume with smaller equipment profiles, so in that regard we aren't answering his question as from my interpretation the question is counter-productive.

producing 120L of double density wort into two 160L fermenters and then topping up with water to produce the full fermenters. To this regard Oginme hit the answer best, but it's not going to get him higher gravity beers thats for sure, not if he's already having an issue hitting higher gravity full boils due to undersized equipment. usually this kills your hop utilization a bit, but otherwise there's no adverse effects.