Scaling recipes up or down........

According to some of the discussion on Probrewer.com, making a bigger or smaller batch is not as simple as taking a recipe for a five gallon batch and multiplying or dividing.

They didn't elaborate, or give any clues as to what factors would be involved. Would the heat of fermentation in a larger batch tend to change the characteristics of the final beer?

Why couldn't/can't you just take a recipe and scale it up or down?

There are some factors to consider, such as hop utilization with water volume, but in general I think you can just scale a recipe up or down. I've scaled down 10 gallon recipes to 5 gallons that way and it's worked fine.

The biggest problem in scaling down is excess boil-off shifting the bittering utilization. That's an easy one to deal with.

Scaling up, you have to start actively controlling fermenter temperatures.

So taking a five gallon recipe, and intending to end up with 30 gallons is not just as simple a multiplying by six?

Is the fermenter temp the only crucial factor?

Scaling 5 gallons to 10 or even 15 can be done pretty successfully with direct proportioning. However, when scaling all the way to 30 gallons, I'd be a little concerned with hop utilization, as d42 mentions.

So, the magic question is, "How would you need to compensate?" More hops, less hops, higher IBU's, longer or shorter boil?

Your goal is identical IBUs with the same boil time. IIRC, it will require (proportionally) slightly less hops. I'll see if I can find a more definitive answer.

This article hints at some of the reasons why hop utilization may differ, but it doesn't give a very definitive answer to your question.

This snippet, however, suggests that we may be arguing a moot point. The difference in utilization when proportionally scaling hops will likely result in a difference of less than 10 IBUs, which lies below the human taste threshold for detecting differences in bitterness. I know we're not talking about changing boil times, but the end result is probably going to be the same...a rather trivial difference in bitterness.

Hi,
In general you can scale the recipe amounts up or down and it will work just fine.

The challenge comes when you change equipment or brewing techniques, as altering boil size or other parameters can change your IBU, mash, color and other settings. That's why a lot of people use brewing software to do this kind of thing.

There is a separate consideration that enters when you brew really big batches (over 20 gallons), in that hop utilization increases in some cases dramatically for large microbrew size batches. This number is equipment dependent, and something that microbreweries need to take into consideration when scaling up test batches. However, for the average homebrewer this is a negligible effect for batches below 20 gallons.

Cheers,
Brad

Actually, if you have the percentages for your grain bill and you know what the IBUs are, you should be able to scale easily in either direction.

To scale from 5G pilot to 1BBL, scale up proportionately them cut hops by 10%...then fine tune but you will be close.

First post, yeah! So I got a Mr Beer for X-Mas, haven't done anything with it yet but I'm planning to start this weekend. I think I'm going to skip the MRB ingredients and do an actual boil so my question is can I just take a 5 Gal recipe and multiply *.4 to get a MRB sized one? Thanks!

PS yes I've read John Palmer and the mr beer thread...some <grin> ...its 142 pages atm