Vinegar Science pt. 5: Recipes

by Arielle Johnson


What follows in our last post in this 5-part miniseries on the hows and whys of vinegar making are some of the recipes we developed using the previously discussed techniques and methods. There are three recipes: one for celery vinegar using the ethanol addition method and single (acetic) fermentation; one for strawberry vinegar using a double (alcoholic and acetic) fermentation and aquarium bubbler; and one for roasted koji ale vinegar, using a triple fermentation (fungal saccharification, alcoholic, and acetic), and passive aeration.

Young Celery Vinegar:

1. Juice celery in a juicer – you should get a yield in juice of approximately 50% of the initial weight.

2. Add high-proof alcohol to the celery juice until the mixture has an ethanol concentration of 6-8%. If you’re using 80 proof liquor to do this, only 40% of what you’re adding is ethyl alcohol so plan accordingly.

3. Add 20% of a raw, unpasteurized vinegar you like the flavour of – either a previous batch of homemade vinegar, a commercial vinegar, or vinegar mother.

4. Submerge an aquarium air pump and airstone in the vinegar, cover the container with something air-permeable, like cheesecloth with a fine weave or a side towel ­(you’ll want to keep fruit flies out but let the air you’re pumping in escape) and aerate the mixture until it tastes strongly of vinegar, approximately 3-8 days.

Alas, a Dane wrote the names, in whose language celery has two ‘l’s (bladselleri)

Strawberry Vinegar:

1. Juice strawberries.

2. You want juice with 12.5-15% sugar to reach 6-8% alcohol post-fermentation. Your juice alone will probably not have this much sugar. Split the juice into two even volumes, reduce one on the stove by about 3/4, then combine them to attain this range. This method assumes you have about 8% sugar in your strawberry juice to begin with. If you have a refractometer, take measurements and calculate; or, cowboy it by taste and let us know how it turns out, we’re curious.

4. Add champagne or white wine yeast to your strawberry juice, seal it with an airlock, and let it ferment until it stops bubbling (it should taste dry and alcoholic), somewhere around 7-14 days.

5. Rack the strawberry wine off the yeast lees, add raw unpasteurized vinegar at 20%, and either aerate or let stand for 2-4 months.

Roasted Koji Ale Vinegar (with botanicals)

(Makes 25 L of beer, 30 L of vinegar)

1. Make Koji: Soak 1.5 kg of pearled barley overnight, steam it for 1.5 hours, cool to 35˚, inoculate with 1.5 g koji spores (1g/kg dry grain if using pure spores; 20g/kg if using koji-kin), spread into a 2cm layer, cover with a damp towel, and incubate in a humid room at 30˚. Stir and turn after 6, 12, and 18 hours. The koji is ready when a fuzzy white mycelium binds the grains together; if it has started turning green, use these parts for spores but don’t cook with them. Roast the koji at 175°, mixing frequently, until it is dark golden brown.

2. For easier fermentation and improved beer flavour, make a yeast starter. Make 2L of wort the day before brewing by diluting malt extract or dried malt in boiling water to about 12-13% sugar, let cool, and add a packet of dried yeast or, better, a tube of yeast culture like White Labs California V Ale Yeast, and let it grow for 24 hours before you brew. Adding this larger amount of yeast to the 25 L of wort stresses the yeast less.

3. Grind 4500 g of Maris Otter Pale Malt or another similar malt, and 1900 g of roasted barley koji.

4. Pre-heat a large insulated container such as a large thermal drink dispenser or cooler by pouring boiling water into it. This container is your ‘Mash Tun’. It will make your life much easier if it has a tap at the bottom out of which you can drain liquid, and even more so if you attach a piece or a cylinder of wire mesh to the opening as a filter)

5. Heat 15 L of filtered water to 72°C. This is your ‘strike water’, and you want it at a temperature so that when you mix it with your grain, they will be at 65°C. Use this calculator for a more precise estimate.

6. Combine the grain and the heated water in the pre-heated insulated container, make sure the temperature of the mixture is about 65°C, stir it, put a lid on it, and let it sit for an hour. Right now you’ve activated amylolytic enzymes in the malt which are converting starches into sugars, and these sugars as well as other flavour compounds are being extracted into the water. The extracted grain is your wort.

7. Heat another 15 L of water to at least 72°C; it can be boiling.

8. After an hour, slowly drain the wort off the grain with the tap on your mash tun. This is called lautering. Minimizing exposure to air, for example by covering the spout with tubing, will prevent oxidative flavors. Your wort will probably be fairly cloudy. If the mash tun has no tap, you can pour all of it through a strainer to separate the spent grain from the wort.

9. To filter the wort further and extract more sugar, slowly pour the drained wort over the grain bed again one or two times, preferably through some kind of perforated plastic so the wort trickles over the whole surface and contacts all the grain.

10. Pour the second batch of 15 L of water slowly over the mashed grain and collect it. Mix the original wort with this second batch of wort. [i]

11. Let the wort cool and take a sample to measure its sugar content by specific gravity. This is done with a hydrometer, which floats in the wort and measures its density by how high or low it floats. Assuming you’ll have a small amount of sugar and other dissolved solids left when the yeast have finished their fermentation, you want an original gravity of about 1055-1060, which means that the wort has a density that is 1.055-1.06 times that of water. A higher gravity means higher sugar, and either a sweeter or higher-alcohol beer. You can add water or boil down to adjust the gravity. You can also check the sugar content with a refractometer, which measures degrees brix, or percentage of dissolved solids calibrated to sucrose.

12. When the wort is at about room temperature, add yeast. We recommend White Labs Burton Ale Yeast, WLP023, as a starting point.  Put the yeasted wort in a sealed container with an airlock and let it ferment until you like the sweetness-alcohol balance; for vinegar you may want to stop it before it gets completely dry. This will take about 1-2 weeks. Either at this point or at the next step when you add vinegar starter, add 0.5-5% by weight of botanicals, depending on intensity and desired aromatic balance. We have used juniper berries, juniper wood, pine needles, liquorice root, and kelp.

13. Add 20% of the volume of beer of unpasteurized raw vinegar to the beer. Cover the container with an air-permeable cover, like a clean kitchen towel or muslin, and let it sit in a relatively warm place for 2-4 months, tasting every 2-4 weeks, until it reaches an acidity level that you like.

[i] At this point, if you want to turn it into beer, you’d take hops, and boil some of them in the wort for an hour and then add the rest to boil for a short amount of time- the long boil transforms some of the hop compounds into bitter-tasting isomers, and the short boil will provide more hop aroma. Hopped beer can be made into vinegar, too.