[brownco]

My understanding is that when a beer recipe is scaled up to a larger size, ingredients and process do not move up in a linear fashion.  Say I want to take a 5 gal brew recipe and scale it up to 1bbl or 2bbl or 3bbl or larger. How do I alter my recipe?  Can anyone point me to a good book or online reference or give me some advice?  Thank you.

[ccarlson]

Use a program such as ProMash. Enter it as 5 gallons and then scale it up with the volume button. The program does it for you.

[dbeechum]

The one real gotcha with linear scaling is that you don't always want to completely linear scale your specialty malts - like the roasts and crystals or smoked malts.

Having said that, you can usually scale linear (ala how ccarlson points out in software or just  multiplying) and then tweak.

[brownco]

Thank you Craig.  I have Promash.  I assumed Promash to calculate a simple linear (ratio based) adjustement of ingredients based upon gravity and IBU.  I am up to speed on this type of calculation.  However I am concerned that through application of a linear scaling, the final product might come out tasting, smelling or looking differently.  It is my understanding that this is something that happens in the culinary world, e.g. you don't make a 50 gal stew by x 10 the ingredients of a 5 gallon stew.  Is my assumption incorrect?  Thank you again for your reply.

[brownco]

Thank you Drew.  From what you are stating, a calculator is of little help with the specialty grain scaling.  Experience with trial and error rule here?  I would assume the starting point for the specialty grains would be the linear approach followed by the tweeking you mention.  Is there a general rule of thumb that applys the the specialty grains as to tweek up or down?  Thanks again Drew.

[dbeechum]

Almost always you're going to be tweaking amounts down.

Here's the rub with scaling - there are so many factors changing between systems that its hard to predict what's going to need to change. The new system produces a more vigorous boil? Tone down the caramel malts, for instance.

You'll notice this sort of effect every time a brewery changes systems or locations. For isntance when Stone moved to their new brewhouse with the very fancy pants system they bought - the beers changed for a while to me.

[EHall]

I can tell you from experience that when I scaled up a 1gal test batch to 5gal, the multipling the victory malt x5 resulted in something different from the 1gal batch...

[SiameseMoose]

I wish there was a good rule of thumb! For background, I'm a homebrewer who currently works as unpaid labor in a microbrewery. Nothing scales linearly. My limited experience is that as you go up in volume the contribution of specialty grains increases, and the hop extraction efficiency goes up. With that said, I'm talking 5 gallon to 10 barrel batches. In scaling a 5 gallon to 15 gallon batch, the relationship is close enough to linear as to be beyond my tasting skills. But beyond that, even I can taste the difference. The relative extraction efficiency of both specialty grains and hops definitely increases as the volume increases. Unfortunately, I do not yet have enough experience to give you a mathematical formula. I hope to give you a better answer, maybe in a year or so. 

[tschmidlin]

Yeah, as Rob pointed out, hop utilization is typically much better in a commercial brewery so you have to take that into account.  If they know their system they will know the utilization, so use that when re-formulating your recipe.