The work was carried out across the central area of England, with a relatively even distribution of small, medium-sized, and larger craft breweries throughout both various urban and rural areas in England (
Figure 1). Forty of the craft breweries were located in urban areas, compared to 50 craft breweries from rural areas. There was a high distribution of smaller craft breweries (<1000 L) located around London. In total this study entailed nine small-, 19 medium-, and 12 large-sized urban-located craft breweries; and 10 small-, 20 medium-, and 20 large-sized rurally-located craft breweries.
4.1. Spent Brewer’s Grain
Regardless of their location or size, the main method of grain disposal is animal feed (
Figure 3). All rural-based craft breweries disposed of their spent grain as animal feed, and so did the larger urban-based craft breweries. However, the medium- and small-sized, urban-based craft breweries found alternative routes of spent grain disposal. The smaller craft breweries opted to have their spent grain being used to produce compost or directly as fertiliser as a sustainable disposal of the spent grains. However, some very small craft breweries had to dispose of their spent grain as landfill waste.
Two-thirds of small urban craft breweries have their spent grain removed from their site on a weekly basis, while the most common disposal frequency for medium-sized and large urban craft breweries was a couple of times per week, at 52.6% and 75% respectively (
Table 1). A greater proportion of the larger rural-based craft breweries had their spent grain removed on a daily basis compared to the small rural-based craft breweries (42.1% vs. 20% respectively). On the other hand, 50% of the small rural-based craft breweries had their spent grain removed 2–3 times a week compared to 31.6% of the large rural-based breweries. A small number of breweries had no set pattern with regards to their spent grain removal, instead the spent grain was removed on the day or after the day of brewing.
Regardless of their location, the vast majority of craft brewers incurred no cost for the disposal of spent grain from their site (
Table 1) . However, on occasion, both the urban and rural small craft brewers faciliated the removal of the spent grain themselves where the costs incurred were man-hours and fuel. Some of the rural-based breweries received payments for their spent grain, a trend only seen among the larger urban breweries.
The brewer from a typical, small urban craft brewery (Brewery US1) was interviewed with regards to their spent grain disposal method. Their spent grain is re-used as animal feed by a farmer. The farmer comes to the brewery and collects their spent grain once a week. The relationship between the brewery and the farmer was originally established with the farmer by a large national brewery who was present on the same site before Brewery US1 was established because the farmer used to collect malt dust from the mill screeners. Once Brewery US1 commenced production on their current site they “asked him if he wanted to utilise the spent grain because we do not produce big enough volumes to use the previous disposal method used by the national brewer” (quote brewer US1, 2017). Brewery US1 has a dedicated HACCP plan in place with regards to regulation EC:183/2005 because the spent grain goes back into the food chain. However, Brewery US1 is not a member of any assurance schemes, such as the one provided by BFBI.
The brewer from a medium-sized urban craft brewery (Brewery UM2) was interviewed with regards to their spent grain disposal method because they use a unique disposal method. Their spent grain is disposed of by a local anaerobic digester plant to produce biogas. The relationship between Brewery UM2 and the company operating the anaerobic digester was established when the brewery concluded that “using an anaerobic digester was the most efficient way to dispose of their spent grain” (quote brewer UM2, 2017) and a brewery representative contacted the plant direct. The anaerobic digester plant is approximately 15 m from the brewery and the only cost the brewery encounters is the transportation of the spent grain from the brewery to the plant. Brewery UM2 has no dedicated HACCP plan in place with regards to regulation EC:183/2005 and is not a member of an assurance scheme because their by-products do not re-enter the food chain.
The brewer from a medium-sized rural craft brewery (Brewery RM3) was interviewed with regards to their spent grain disposal method. The spent grain from Brewery RM3 is re-used as animal feed by a local farmer who is located approximately 5 m from the brewery. The relationship with the farmer is a historical relationship through local acquaintance. Brewery RM3 has a dedicated HACCP plan in place but are not a member of an assurance scheme because “it costs money for no return” (quote brewer RM3, 2017). Despite not being a member of an assurance scheme, their grain has been tested several times for toxins by local trading standards. Similarly, the brewer from another medium-sized rural craft brewery (Brewery RM4) was interviewed with regards to the disposal of their spent grain because they supply a local bakery with their spent grain. The local bakery contacted the brewery about potentially using spent grain from Brewery RM4 in their bread. Prior to supplying the bakery with their spent grain, the brewery disposed of their spent grain as animal feed. An understanding established that the bakery is responsible for the legal requirements of spent grain entering the food chain. Although brewery RM4 does have a HACCP plan in place under regulation EC:183/2005 and is a member of an assurance scheme.
A representative from a large rural craft brewery (Brewery RL5) was interviewed with regards to their unique and integrated method of spent grain disposal. Their spent grain is used as animal feed by a local pig farmer. They use this method as a unique marketing tool because they use a high-profile local farm who uses the spent grain to feed their pigs; these pigs are then used to provide pork for the brewery’s tap house. Customers visiting the brewery and/or the tap house are offered pulled-pork rolls from pigs fed on the spent grain that came from the brewery. Essentially, the spent grain goes in a cycle back to the brewery enabling them to sell their story as “a local craft brewer who collaborates with a local farm business in a locally sustainable manner” (quote brewer RL5, 2017), where the story is personably relatable. Brewery RL5 has a dedicated HACCP plan in place under regulation EC:183/2005 and the company is a member of the assurance scheme provided by BFBI.
A large rural-based craft brewery (RL6) stood out because of their collaborative approach to spent grain disposal. Their spent grain is used as animal feed by a farmer, who collects the spent grain on a weekly basis. The relationship with the farmer is a historical relationship through local acquaintances. The collaboration with the smaller brewery is also through local acquaintances and it allows the smaller brewer to dispose of their spent grain in a sustainable manner, because, by themselves, the smaller craft brewery would not produce sufficient volumes of spent grain to engage directly with a farmer to take their spent grain. Brewery RL6 and the small brewery they collaborate with both have a dedicated EC:183/2005-HACCP plan in place, however, only the larger brewer is a member of the assurance scheme provided by BFBI.
4.2. Spent Brewer’s Yeast
While most breweries with sufficient production frequency re-use some of their relatively fresh yeast to inoculate the next batch of wort, the vast majority of surplus yeast was treated as spent yeast. The most common disposal method for spent yeast by both rural and urban craft breweries is via their sewage system (
Figure 4). However, the use of yeast disposal through the sewage is more prevalent among the smaller rural and urban craft breweries, and decreases in prevalence with increasing batch volume sizes. While some small urban craft breweries dispose of their spent yeast as an animal feed source, this disposal method is more frequently employed by medium-sized and larger rural craft breweries (approximately 20% each) (
Figure 4B). Both rural and urban craft breweries dispose of their spent yeast for composting purposes; while direct use as fertiliser is common among the urban craft breweries (
Figure 4A). A small number of small and medium-sized, urban and rural craft breweries mix their spent yeast with the spent grain before it is carted off to a farmer, and in one instance for use as mixed substrate in an anaerobic digester. One large urban craft brewer disposed of its surplus yeast by selling it to a distillery as the inoculum for their fermentation; while two urban breweries had their spent yeast collected by commercial trade waste companies.
The vast majority of craft brewers disposed of their spent yeast within a couple of days of the yeast becoming surplus to their own needs, regardless of the location or batch capacity. However, regardless of location the small craft brewers tend to dispose of their spent yeast daily, and the larger the brewery becomes the less likely it is that the brewery disposes of their spent yeast immediately (
Table 2). Some brewers store their spent yeast in a dedicated tank and the yeast is collected until the tank is sufficiently filled and is emptied when required. In one instance the rural craft brewer indicated that the spent yeast is collected in a tank, which (when emptied) is sprayed onto fields as fertiliser. Similar to the frequency of spent yeast disposal, regardless of the location, the small craft brewers are less likely to incur any costs with regards to spent yeast disposal; while the larger the brewery’s batch capacity is, the more likely it is that the brewery pays some or all the costs of spent yeast disposal. Only two large urban-based craft brewers received payment for their spent yeast (
Table 2).
The brewer from a small rural craft brewery (Brewery RS7) was interviewed with regards to their spent yeast disposal via the sewage system. Brewery RS7 expressed that they used the sewage system to dispose of the spent yeast because they “do not brew often enough at the correct gravity to maintain a yeast culture, so we do not collect the yeast” (quote brewery RS7, 2017). They explained that their water provider has been informed that this is their disposal method and that they are happy with the brewery using this method and their water rates have not been affected. The medium-sized, rural-based brewery (RM3) disposes of their spent yeast by means of the sewage system. During an interview the brewer from brewery RM3 stated that “the big breweries in our location send their spent yeast to the Marmite factory”, and subsequently indicated that they did not produce enough spent yeast to use this method of spent yeast disposal. Brewery RM3 holds a permit from their water supplier to dispose of their yeast in this manner.
The brewer from a large rural craft brewery (Brewery RL8) was interviewed with regards to their unique disposal method for both their spent grain and spent yeast. Currently, both their spent grain and spent yeast are disposed of through a local farmer who has installed an anaerobic digester plant. The relationship was established with the farmer from the start of the brewery’s production, when the farmer collected the spent grain from brewery RL8 for animal feed. Since the installation of an anaerobic digester by the famer, the famer has been taken both the spent grain and spent yeast. The brewer (RL8) stated that “being a rural business disposing of spent grain and spent yeast using an anaerobic digester plant is the most efficient method”. The brewery maintains a dedicated EC:183/2005-HACCP plan and are a member of the assurance scheme provided by BFBI even though they have now changed their disposal method from animal feed to substrate for an anaerobic digester.
Two large craft brewers (one urban and one rural) discharged their yeast effluent in ponds. The urban-based craft brewer stated that they used anaerobic ponds; while the rural craft brewer operated a series of reed beds. The rural brewer (RL9) explained that this option of disposal is used because of their isolated rural location and that the brewery received a grant to setup the reed beds. Since the reed beds were installed the brewery has markedly increased its production volumes. The brewery’s representative stated that to cope with increased volumes they had to “increase the size of the swell dish and add another pond, we also installed a compressor in the last pond to increase the oxygen levels before the reed bed run-off entered a natural water source so to ensure that the native aquatic live was not affected by the influx of oxygen depleted water” (quote: brewery RL9, 2017). In order to use this method brewer RL9 communicated with their water authority and gained their consent.
4.3. Spent Brewer’s Hops/Hot Trub
The most common disposal method for spent hops is for fertiliser, however in comparison to the other by-products spent hops/trub shows a larger distribution of methods used by breweries (
Figure 5). Even so, none of the craft brewers specifically disposed of their spent hops/trub for animal feed. However, spent hops/trub is frequently mixed with other spent material, usually with spent grain. Even though hops add a strongly bitter taste to the feed which reduces the feed quality [
29]. Some brewers indicated that their spent hops are bagged up and made available for whoever was interested in taking it. Taken spent hops from craft breweries appeared a popular means for allotment gardeners to enrich their soils, either as compost or as ‘green soil conditioner’.
Spent hops/trub is probably the least voluminous of the principal brewery waste products considered here and can be stored for some time. The small, urban craft breweries tend to have their spent hops removed once a week, compared to their medium-sized and large craft brewing urban colleagues who accumulate their spent hops faster and tend to dispose of the spent hops 2–3 times a week (
Table 3). The rural craft brewers dispose of their spent hops/trub in a somewhat more ad-hoc manner with a large proportion having the ability to dispose of their spent hops once a week. The vast majority of craft brewers do not incur any costs with regards to the disposal of their spent hops. However, in some instances the brewers either contribute to the cost of spent hops/trub disposal or incur all costs. Very few craft brewers receive payment for their spent hops/trub.
The representative from a large rural craft brewery (Brewery RL5) was also interviewed with regards to their method of spent hops disposal. The hops are disposed of at the same farm that utilizes their spent grain. However, instead of being used as animal feed, the spent hops are “used by the farmer as a great soil improver, allowing the soil to retain more moisture” (quote: brewer RL5, 2017). The large rural brewery produces a large volume of spent hops and from time to time pay for a digger to be hired to help the farmer dig the spent hops into the soil.
The brewer from a small, urban brewery (US9) stated that all their spent grain, yeast and hops are removed from their site for use in an anaerobic digester. The brewer went on to say: “'I use the biogas, as it is eco-friendly”, and “secondly it allows me to dispose of grain, hops and yeast etc. in the same containers”. “This nice and efficient with regards to one pick-up, one relationship, and one invoice. It is a contractual relationship between two limited companies, I pay a deposit for the bins and then a collection fee when I request a pickup.” The brewer went on to indicate how the relationship started and said: “It is reasonably priced, and I needed disposal that week and they could get setup quickly. I had their number from a fellow brewer who was impressed with their reliability. Some farmers are not as reliable and can leave you with 500 kg of rotting grain. This way just works.” (quote: brewer US9, 2017)
Another urban brewery (UM10) was also interviewed with a principal discussion point being their spent hop and spent yeast disposal method. They dispose of both through a bio-recycling company for large-scale organic material composting. The relationship was established by the brewery through contacting the company after researching food waste collection companies within their urban area. This medium-sized urban brewery chose this disposal method mainly because “this method specifically benefits the environment” (quote: brewer UM10, 2017).