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Gladfield Sour Grapes Malt (Acid Malt)

specialty malt · Gladfield Malt · New Zealand

New Zealand acidulated sub-base malt from Gladfield. Produces lactic acid during germination (2% acid content) — 1% of grist drops mash pH by approximately 0.2. Use 1–5% to hit target mash pH. Can also contribute a mild lactic tartness to the finished beer.

mild lactic tartnessslightly acidicclean

8 brews

About

Sour Grapes is Gladfield's acidulated malt, made by encouraging lactic growth from naturally present bacteria during germination and then washing the malt in a lactic bath with the same Lactobacillus strain before kilning. At about 2% acid content it is a clean, repeatable way to lower mash pH — roughly 0.2 pH per 1% of grist — and at the upper end can lend a mild lactic tartness to the finished beer.

Specs

Colour
3–6 EBC
Extract (FD)
26%
Max usage
5%
Moisture max
6.5%
Diastatic power
0 °WK

Usage

Use 1–5% to dial in target mash pH (about a 0.2 drop per 1%). A clean alternative to acid additions; at the higher end it also adds a gentle lactic tang, useful in hazy IPAs and light sours. Low extract, so it adjusts pH more than it contributes fermentables.

In your brews

Used in 8 brews 2020-05-03 → 2025-02-23
Total used 1.87 kg
Grain bill 4.2% range 3.1–6.1%

Styles brewed

18B American Pale Ale
5
2B International Amber Lager
2
21C Hazy IPA
1

Used in