If you are a traditionalist, there are only four ingredients in beer.... water, malt, hops, and yeast. Contemporary colleagues will diverge, with almost nothing considered out of bounds. Either way, current world logistics can leave many shorthanded. Proper batch scaling and material sourcing will insulate from supply chain disturbances. 

One way to minimize impacts is to diversify vendors. Keeping several options allows for quick acquisitions when the need arises. Consider inventory increases as another layer of safety. Storing enough raw ingredients for one batch is a bare minimum. Realistically, a two-month supply should be standard, to allow enough time to scour alternative sources should stock run out. Sales representatives will often convey potential issues they are aware of, but even producers can get caught off guard by weather, tariffs, or pandemics. 

Although hops and malt are seasonal raw ingredients, modern processing has made them storable for extended periods. Weyermann malt, a gold standard manufacturer, offers a minimum shelf life of 18 months after manufacture for most unopened products, and Hopsteiner suggests a best before date up to 5 years out for pelletized hops. Dry yeast from Fermentis is vacuum stored in mylar bags can be kept for up to 36 months without significant decline. Liquid yeast cultures are not as forgiving, but they can be stored for extended periods with extra care. As with all thing's beer, fresh is best, so use ingredients as quickly as possible.  

The best way to perfect a brew is at scale, however this is not always an option. Brewing small pilot batches is one way to skirt the cost of ingredients, energy, and cellar space. Once refined, scaling up to the desired batch volume is not difficult. If known, consider adding any process loss to your desired fermenter volume. This ensures maximization of fermenter space and time. 

Many quality programs exist that can build, scale, and even categorize a brew recipe with just a few clicks. Beer Smith, The Brew Cloud, and Brewers Friend are just a few. Advantages are exponential, including scaling for evaporation or efficiency calculations. Coupled with the ability to save and recall recipes at a future date, there are few reasons to avoid brewing programs today.  

For those who prefer a more traditional approach, consider using percentages. From here, increasing malt bills is relatively linear. Simply factor by the desired percentage increase in volume, for each line item. This same math can be applied to yeast nutrients, kettle finning's, and brewing salts. Unfortunately, hops are not so easy to scale.  

International Bittering Units (IBUs) are the measure of choice for brewing recipes, but there is a lot of minutiae involved. Without a spectrophotometer it is very difficult to exact an IBU from wort or beer. When hops are added to wort, several factors influence their impact. Time and temperature are the most influential, and an increase in either will increase perceived bitterness. Depending on the way traditional hops are processed, they may be designated whole cone, type 45, or type 90. Whole cones are plucked right off the vine, but type 45 and type 90 are a bit more refined. 

The type designation of hop pellets, T45 and T90, represent the percentage of hop material pelletized after processing. While T90 processing removes primarily the strig, T45 removes the strig as well as some of the bract and bracteoles. Since the yellow lupulin glands at the base of the bracts and bracteoles are what brewers value, type 45 pellets offer the most concentrated value in standard offerings. Lupulin powder, alpha-extracts, and cryo-hops offer additional ways to decrease the amount of vegetal material used in brews.

Hop utilization refers to the quantity of alpha acids that are isomerized and remain inside the wort. When scaling recipes, this becomes a very important factor. The amount of isomerized acid is directly proportional to the perceived bitterness of the finished product. When you scale, check to see if a utilization factor for the brewing system is known. This will aid in adjusting hop additions. 

In most cases, hop utilization is in the 25-28% range over the course of an hour boil. This can increase to 30-33% if the boil time is lengthened to 90 mins, but many factors are at play. Besides time and temperature, specific gravity and pH of the wort impact isomerization. Note the pH on pilot brews and be sure to adjust batches to match as close as possible.