Viewing entries tagged
Sustainability

Zero Plastic: A Backward Step?

Zero Plastic: A Backward Step?

One of the goals of our sustainability work is to be free of single use plastic in the distillery. That’s been a goal from day 1 and so we’ve never really used much anyway. We used plant-based plastic (PLA) straws for a while but we’ve phased these out in favour of paper ones.

We still use PLA tasting cups for events, which are better then oil-based plastic, but still not ideal due to commercial composting requirements.

PVC shrink capsules. To be replaced with PLA or discarded altogether.

PVC shrink capsules. To be replaced with PLA or discarded altogether.

The one thing we do use are PVC shrink capsules around our bottle tops. We feel like we need these to get our products around the world in perfect condition, and are hunting a manufacturer to make these from PLA for us (100,000 minimum order quantity so far), but will ditch them altogether if we can’t do that.

Then there is the stretch wrapping commonly used to secure pallets of stock - we can have giant reusable socks made which stretch over pallets to secure the cases, but that does rely on our customers collecting and returning them, and we are talking to our regular volume clients about the feasibility of this. We use a small amount of inflatable PET to pack our retail sales, and we mark our shipments so people know to recycle it, but again, are hunting alternatives.

So that’s been it until we recently took two backward steps.

Temporary - Corks

Our journey in closures (l-r): natural Cork, plastic shank, natural Cork with black painted wood.

Our journey in closures (l-r): natural Cork, plastic shank, natural Cork with black painted wood.

We’ve used natural corks from day 1. This is unusual in spirits as the manufacturers communicate a risk of colour taint which puts people off, but the risk and impact is small, and to us does not outweigh the issue of using disposable plastic or composite versions.

We really misunderstood the impact that the use of plastic corks has on the lead time of natural corks - our latest order was to take 5 months. We were sent plastic alternatives which match our preferred visual style of natural wood, but introduced single use plastic back in.

We preferred to switch to a black painted stopper which used natural cork even though it changes the look of our bottle. Better a temporary visual change then plastic corks, goes the thinking.

We’ll think 6 months ahead from now.

Permanent - Labels

Glassine backing paper (right) replaced with recyclable PET (left)

Glassine backing paper (right) replaced with recyclable PET (left)

Pretty much every label which goes on anything is supplied to the manufacturer on Glassine paper, a siliconised paper which is not practically recyclable.

So we’re changing to PET backing material for our labels based on the belief that using a material which is recyclable is better then one that isn’t, even if the initial impact of manufacture is higher (we’re not sure if it is or isn’t).

We didn’t know the options until we faced the problem of recycling our glassine - it would have been handy to know as we have had to have all our label die cutters re-made for PET. Who knows how many kilos of PET we’ll need to recycle to offset those metal dies.

So a permanent introduction of single use plastic, to mitigate a non recyclable alternative. an unappetising trade.

 

Building a Heat Recovery System

NOTE: This journal entry is a bit more technical then usual to give enough guidance to other distillers wanting to do something similar. If that's you, please note that pumping hot liquids is a dangerous business and our design is no guarantee of safety. If you can't calculate the technical requirements of your system then find someone that can.

As we grow and develop our distillery we maintain a list. It's a list of the things still to do to achieve our ultimate goal of zero waste.

This list is ranked, sadly not by ease of implementation, but by environmental impact. Way up there is waste heat.

Targeting zero waste

Distilling is a wasteful business. Our core role is to heat up liquid and cool it down again straight away. The specific heat capacity of water is 4185.5 J/(kg⋅K), which means it takes a LOT of energy to heat it up.

Once we've heated it up and boiled it for a while to extract the delicious, delicious ethanol, we're left with a volume of hot liquid (like, 98 degrees hot, called 'stillage') and a volume of hottish water used for cooling (60ish degrees, 'condenser water').

Now, we use a 100% renewable supply to heat it, but that doesn't mean we should be wasteful with that energy.

We need to strip out the heat energy for 2 reasons - 1) Our aim of zero waste includes heat energy that can be recovered and reused, and 2) all our liquid waste goes to our biodigester to be processed using green energy. Too much hot stillage would nuke the bacteria in the biodigester rendering it useless, and as we grow that's becoming an issue.

Build or buy?

Specialist heat recovery systems for distilleries tend to cost hundreds of thousands and are designed to suit distilleries which operate at full capacity five or seven days a week. Better for us to build one completely suited to our needs.

Ours essentially has three components:

  1. An insulated thermal store. We discharge the stillage into this along with some of the condenser water - not too much of the condenser water as we have other uses for that and we want the temperature to be as high as possible for maximum efficiency. If we don't want to use the heat energy for a couple of days that's fine, it'll stay hot in the store for when we need it. If we don't have a use for it, then a radiator is plumbed into the store and will vent the heat slowly to the distillery over a week or so.

  2. A wash feed circuit. This brings cool wash from the fermenter through 60m of coil in the thermal store which heats it up a bit, then through a plate heat exchanger where it picks up some more heat, and then to the still by which time it should be pretty hot.

  3. A hot circuit. This pumps stillage out of the thermal store around the plate heat exchanger, both to warm the wash feed in the plate exchanger and to circulate the stillage in the thermal store to maintain efficient heat transfer

The net result of this is we bring the wash from a fermenter temperature of 12 degrees to 55 degrees in the still, while reducing the stillage temperature from 95 degrees to a balmy 40 degrees (ish).

Operation

It works like this. In Fill mode (below) the stillage is pumped from the still (through a filter to remove debris) into the thermal store holding vessel.

FILL-MODE.jpg

The stillage feeds into the top of the thermal store where there's also a fill point for condenser water here which doubles as a vent point (we can close this but it must never be sealed completely). The volume of the store is such that if we ONLY use stillage then the coil is covered completely.

VESSEL-TOP.jpg

When we're charging the still, the wash pump is pumping wash through the coil, through the plate heat exchanger, to the still.

The high temperature pump is circulating the stillage through the plate heat exchanger and around the thermal store.

CHARGE-MODE.jpg

When we're done, we have a still full of hot liquid ready to distll, and a thermal store full of warm liquid ready to be dumped to the biodigester.

DUMP-MODE.jpg

Notes for Distillers

  • We mainly use this for stripping runs. You obviously don't want your fine spirit run to be hot too fast otherwise you won't get good separation of heads cuts.

  • Note we've mounted the plate exchanger on a few bits of timber so we can remove these easily and drop the exchanger off for maintenance.

  • Don't run you gin through this. It wouldn't be safe at that charge abv and it wont make for a nice spirit, but do use the gin stillage for heat recovery.

Materials List

  • High-temperature Pump - Lowara Stainless Steel 415V from www.anchorpumps.com

  • High-temperature suction hose (from still to system) - www.ebay.co.uk/usr/hosemaster64

  • Plate heat exchanger - Wiltec Stainless Steel Heat Exchanger 60 Plates 130 kW

  • Thermal Store (See Below) - Custom build from www.worldheat.co.uk

  • Connections - www.ukpumpsupplies.co.uk & www.screwfix.co.uk

1 - Coil Connections 2 - Vessel Fill 3 - Vessel sight, condenser fill & vent 4 - Vessel Dump 5 - Radiator Connections

1 - Coil Connections
2 - Vessel Fill
3 - Vessel sight, condenser fill & vent
4 - Vessel Dump
5 - Radiator Connections

All hail the apple

All hail the apple

How blemished does an apple have to be before you turn your nose up? Well, the supermarkets think not very. In fact, supermarkets, on your behalf,  won't accept many blemishes at all.

I was at the UK Fruit Show last week and took this photo of some extremely shiny apples. Perfection not far removed from what we are presented in the aisles. 

IMG_20161019_114238.jpg

New friends and local apple farmers, Peter & Gina, farm a few hundred acres a mile or so from the distillery.  In early summer this year, a freak hail shower passed through their orchards when the apples were golf ball sized, affecting a little under half the crop. 

The photo below is of one of the worst affected apples; most had one or two small dimples on, but still enough to make them unsaleable to supermarkets. 

IMG_20161021_132529.jpg

The fruit is now fully ripe and delicious, but can only be sold as juicing stock. Such a large amount of juicing stock causes a problem: it won't generate enough revenue to make it worth running the cold stores so needs to be sold straight away.  

This is the raison d'etre for Greensand Ridge Distillery. To be able to step in and take what may end up as waste, support local farmers and use amazing produce for mouthwatering spirits!